[br]

Combination of photometric and RGB filters to highlight dark nebulae

Photographing dark nebulae is a fascinating challenge for astrophotographers, often posing difficulties due to the low brightness and high contrast between celestial objects and dark nebulae. This often requires the use of different techniques and exceptionally dark skies to bring out fine details in the dark nebular structures.

In this test report, we examine the photographic results and the effectiveness of the combination [product sku="cmosSLOANset" style="imgright"] und [product sku="cmosRGBset"] to evaluate its effectiveness in improving contrast and detail, as well as enhancing them in all their colorful glory, while maintaining natural color reproduction.

Equipment used:

All single frames and the final image were taken with a [product sku="1931096" style="imgleft"]and the Celestron RASA 11“ as well as a selection of 9 different filters, which were changed manually using the UFC (Univeral Filter Changer) System.

The following filters were used:

The entire system was controlled and monitored by the N.I.N.A. imaging software. Filters were changed manually using the UFC Filter Changer. After each filter change, an automatic focusing motor was used to refocus (always after 90 minutes or sooner if the temperature dropped rapidly) in order to always hit the perfect focus point. Flat frames were taken at the end of the filter session BEFORE each filter change.

Gain settings:

High Gain Mode Gain 0 / Offset 25 (for all wideband exposures)
High Gain Mode Gain 56 / Offset 25 (for narrowband exposures)

Acquisition conditions and software:

The images were taken far from optimal conditions under city skies. With an exposure time of over 70 hours, spread over all filters, the images were taken on every clear night with good seeing conditions between May 2023 and July 2023. The main image shows the reflection nebula Van den Berg (vdB) 152 in the constellation Cepheus together with the very faint and diffuse molecular cloud LDN 1217 (LDN = Lynds Dark Nebula). The object is also known among astrophotographers as "Wolf's Cave Nebula".

Details on filter applications:

Photometric filters to increase contrast:

The use of photometric filters in combination with RGB-Filters led to a significant increase in contrast in the dark nebulae regions. The use of SLOAN g‘, SLOAN r‘ and SLOAN i‘ improved the visibility of fine structures and details, while RGB filters preserved the natural colors.

The three central filters used for the Sloan Digital Sky Survey (SDSS) divide the spectral range into three roughly equal parts: g': 410nm to 550nm, r': 555nm to 695nm, and i': 695nm to 845nm. These filters are therefore the perfect choice for three-color imaging with modern cameras.

Wavelength range of the Celestron RASA 11": The manufacturer specifies the Celestron RASA 11“ with an optimized wavelength range of 400 to 700nm. However, the test with the SLOAN i‘ Filter (695-845nm) clearly shows that a sharp and detailed image is also possible far beyond the fully corrected range. The prerequisite for this is refocusing after each filter change.

Filters for the reduction of light pollution:

The application of the [product sku="uhcl" style="imgright"], as well as the IDAS LPS-P2, were used to capture the luminance images. The UHC-L booster filter, which was also specially designed to reduce light pollution, led to a considerable improvement in image quality. The sky appeared darker, which significantly increased the contrast to the dark nebulae. In combination with the LPS-P2 luminance filter, this led to better recognition of fine details and structures.[br]

Use of the f/2 Ultra-HighSpeed H-alpha narrowband filter:

By integrating the narrow-band [product sku="cmosHaUltraHighspeed" style="imgright"] certain emission lines could be selectively emphasized. The hydrogen regions, which are rather weak for color filters, could be precisely extracted and re-inserted into the final color image in the subsequent image processing. This helped to enhance the structures around the dark nebula and the H-alpha regions.

Combination of RGB filters for natural colors:

Using RGB-Filters alone tended to reduce the contrast between the sky and dark nebulae. The integration of photometric filters helped to increase this contrast, while RGB filters preserved natural colors and allowed for a balanced color appearance.

Overall appearance and aesthetic gain:

The combination of photometric and RGB-Filters resulted in impressive structures within the dark nebula LDN 1217, emphasizing the fine details and structures while preserving the natural colors, resulting in an aesthetically pleasing and well-balanced image.

Image in full resolution: vdB 152 - Wolf's Cave Nebula (SLOAN g'r'i' + HaLRGB)

Acquisition details:

Bildautor: Yannick Akar
TelescopeCelestron RASA 11“
CameraQHY268M Photo
MountiOptron CEM120
AccessoriesBaader UFC, Baader UFC Tilter, Celestron Focus Motor, Pegasus Astro UPB v2
Total exposure time70.3 hours
Filters:
Red
Green
Blue
SLOAN g‘
SLOAN r'
SLOAN i'
UHC-L
IDAS LPS-P2
H-Alpha f/2 3.5nm
3.25 hours (195 x 60”)
3.15 hours (190 x 60“)
3 hours (180 x 60”)
5.4 hours (325 x 60”)
6.3 hours (380 x 60”)
8.5 hours (340 x 90”)
6.4 hours (385 x 60”)
12,7 hours (1525 x 30”)
21.5 hours (645 x 120”)

Note from Baader Planetarium: The following article was kindly provided to us by Christoph B. for publication.


Discover this 2.1M Classic Slit Dome also on our World Map[br]

Background

My journey to establishing my own observatory began with an extraordinary heirloom, a Baader observatory dome over 30 years old, carrying its own remarkable history. This dome had been in the possession of Mr. Ernst Blättler (✝) for decades, who had donated it to his club, the Astronomical Society of Zürcher Oberland (AGZO), some years ago. Until his old age, he was active as a passionate demonstrator. A few years ago, however, the club expressed the desire to operate a modern dome with the latest technology, which could be remotely operated by the club members.

Therefore, the club ordered a new 2.1m split dome, which was installed in September 2020. The heirloom, the over 30-year-old manually operated dome, was kindly left to me by AGZO. This dome, a testament to artisan craftsmanship and enduring quality, thus came into my possession and offered me the unique opportunity to transform it into a functional, modern observatory – a project that not only reflected my passion for astronomy but also a deep appreciation for astronomical heritage.

The challenge was to restore this historic dome, which had observed the sky for decades, and equip it with modern technology. It was a journey full of technical, physical, and emotional challenges. This dome had its own personality – shaped by its past, age, and many stories it had collected over the years. My goal was to not only breathe new life into it but also transform it into a modern observatory that could utilize the latest astronomical technologies.

Refurbishing the Classic Baader Dome

Restoration and Construction

The restoration of the dome was a mix of challenge and passion. Thanks to the know-how and materials from my brother-in-law's boatyard, I was able to breathe new life into the dome. The dome quality was impressive, and after replacing the rubber parts and rollers and repairs to the gelcoat, the dome shined like new.

In May 2023, I was finally able to start assembling the dome. The previous months were marked by continuous rain, which slowed down the excavation, formwork, and reinforcing work. I chose self-leveling pump concrete for the foundation, as direct access for a conventional concrete mixer was impossible. Within 10 minutes, the nearly 2.5 cubic meters of concrete were poured, and after two weeks, I could de-shutter. Then in early June, the dome and mount were set up in one day.

Technical Challenges

An important step was determining the precise position of the pillar. I had previously set up all the equipment in the dry in the shed to test the positioning. After Baader Planetarium warned me about the dimensions of the large refractor in a 2.1m dome, I left nothing to chance. A few days after the dome was set up, the mount and finally the telescope were installed and both were put into operation. More on this below.

Weather Resistance and Practical Test

The dome was already exposed to extreme weather conditions, including a heatwave of over 36° C and two thunderstorms, one with 120 km/h winds and heavy rain. The dome withstood, and thanks to the replacement seal kindly provided by Baader Planetarium for free, the interior remained dry.

As already mentioned, I am thrilled at how well the dome could be renovated. Although it was a lot of work as mentioned above, without the substance of the object, the best polishing machine is useless. And the substance of the dome is first-class.

State-of-the-Art Instruments

Commissioning the Mount

The mount, a 10Micron GM3000 HPS, was another crucial factor. The commissioning was surprisingly simple:

I started with a short drift alignment as I was used to, and already saw that there was no PE. Then I conducted a 10-point alignment with Mount Wizzard 4. After adjusting Polaris and generating a 60-point model, I was impressed with the precision and performance of the mount. The images in long exposures, such as 15 minutes on M101, were visually and metrically flawless – only turning the dome made me sweat.

First Astronomical Successes

After these results on the first evening, I was overwhelmed. The mount enables absolutely precise and clear shots, commissioning completed successfully in one night! Particularly impressive were the results in unguided long exposures.

In the following weeks, I stayed with the Crescent Nebula and was able to collect 7h Ha and OIII with 10min subs each, as well as 14*3min RGB for the stars. All un-guided! Below I show the first finished processed image, for a First Light I am already extremely satisfied.

NGC 6888 – 7h Ha and OIII with 10min subs and 14x3min RGB

Final Remarks

As you can see, I am thrilled so far. The 30-year-old dome is brilliant and now shines again in full splendor – the mount alone could already become a hobby. The next project step will be the automatic rotation of the dome, so I don't have to turn it every 15 minutes – but this is currently only in the planning phase.

I am extremely pleased that this dome with a long history will continue to serve me well for many years.


Sure, here's the English translation:


FROM A FOUND OBJECT TO A MODERN OBSERVATORY: THE STORY OF MY "ANTIQUE" BAADER DOME Note from Baader Planetarium: The following article was kindly provided by Christoph B. for publication.

Discover this 2.1M Classic Split Dome also on our world map Background My journey to establishing my own observatory began with an extraordinary heirloom, a Baader observatory dome over 30 years old, carrying its own remarkable history. This dome had been in the possession of Mr. Ernst Blättler (✝) for decades, who had donated it to his club, the Astronomical Society of Zürcher Oberland (AGZO), a few years ago. Until his old age, he was active as a passionate demonstrator. A few years ago, however, the club expressed the desire to operate a modern dome with the latest technology, which could be remotely operated by the club members.

Therefore, the club ordered a new 2.1m split dome, which was installed in September 2020. The heirloom, the over 30-year-old manually operated dome, was kindly left to me by AGZO. This dome, a testament to artisan craftsmanship and enduring quality, thus came into my possession and offered me the unique opportunity to transform it into a functional, modern observatory - a project that not only reflected my passion for astronomy but also a deep appreciation for astronomical heritage.

The challenge was to restore this historic dome, which had observed the sky for decades, and equip it with modern technology. It was a journey full of technical, physical, and emotional challenges. This dome had its own personality - shaped by its past, age, and many stories it had collected over the years. My goal was to not only breathe new life into it but also transform it into a modern observatory that could utilize the latest astronomical technologies.

Refurbishing the Classic Baader Dome Restoration and Construction The restoration of the dome was a mix of challenge and passion. Thanks to the know-how and materials from my brother-in-law's boatyard, I was able to breathe new life into the dome. The quality was impressive, and after replacing the rubber parts and rollers and repairs to the gelcoat, the dome shined like new.

In May 2023, I was finally able to start assembling the dome. The previous months were marked by continuous rain, which slowed down the excavation, formwork, and reinforcing work. I chose self-leveling pump concrete for the foundation, as direct access for a conventional concrete mixer was impossible. Within 10 minutes, the nearly 2.5 cubic meters of concrete were poured, and after two weeks, I could de-shutter. Then in early June, the dome and mount were set up in one day.

Foundation Preparations

Finished Foundation with Self-Leveling Pump Concrete

Assembling the Dome

Technical Challenges An important step was determining the precise position of the pillar. I had previously set up all the equipment in the dry in the shed to test the positioning. After Mr. Risch warned me about the dimensions of the large refractor in a 2.1m dome, I left nothing to chance. A few days after the dome was set up, the mount and finally the telescope were installed and both were put into operation. More on this below.

The GM 3000 HPS on the Baader Steel Column

My CFF 185mm APO on the GM 3000 HPS Mount

The Finished Dome Shines in New Splendor Weather Resistance and Practical Test The dome was already exposed to extreme weather conditions, including a heatwave of over 36 degrees and two thunderstorms, one with 120 km/h winds and heavy rain. The dome withstood, and thanks to the replacement seal kindly provided by Baader Planetarium for free, the interior remained dry.

As already mentioned, I am thrilled at how well the dome could be renovated. Although it was a lot of work as mentioned above, without the substance of the object, the best polishing machine is useless. And the substance of the dome is first-class.

State-of-the-Art Instruments Commissioning the Mount The mount, a 10Micron GM3000 HPS, was another crucial factor. The commissioning was surprisingly simple:

I started with a short drift alignment as I was used to, and already saw that there was no PE. Then I conducted a 10-point alignment with Mount Wizzard 4. After adjusting Polaris and generating a 60-point model, I was impressed with the precision and performance of the mount. The images in long exposures, such as 15 minutes on M101, were visually and metrically flawless – only turning the dome made me sweat.

First 60-Point Model

45 minutes later 3.1 RMS and 55” PA Error First Target, 10 min. exposed: WOW – absolutely round stars

Next Target: M101 15 min exposed, still round measured stars

Third Object NGC 6888 - 20 min exposed on the other pier side First Astronomical Successes After these results on the first evening, I was overwhelmed. The mount enables absolutely precise and clear shots, commissioning completed successfully in one night! Particularly impressive were the results in unguided long exposures.

In the following weeks, I stayed with the Crescent Nebula and was able to collect 7h Ha and OIII with 10min subs each, as well as 14*3min RGB for the stars. All un-guided! Below I show the first finished processed image, for a First Light I am already extremely satisfied.

NGC 6888 – 7h Ha and OIII with 10min subs and 14x3min RGB Final Remarks As you can see, I am thrilled so far. The 30-year-old dome is brilliant and now shines again in full splendor – the mount alone could already become a hobby. The next project step will be the automatic rotation of the dome, so I don't have to turn it every 15 minutes – but this is currently only in the planning phase.

I am extremely pleased that this dome with a long history will continue to serve me well for many years.

Acknowledgments

I would like to thank AGZO for generously leaving the dome to me and especially Baader Planetarium for their support and the provided seal. Without their products and their service, I could not have realized this project. My dream of owning my own observatory has become a reality.

Christoph B., November 2023


Notice: Trying to get property of non-object in /home/baadercom/public_html/blogs/wp-content/themes/fishpig/local.php on line 458

Takahashi is known for excellent telescopes, but when it comes to adapting accessories, they sometimes go their own way, which can make life hard for astronomers. In particular, the use of a bino viewer on the Takahashi Mewlon kept raising questions, and since we don't sell Takahashi telescopes, we couldn't simply try it out ourselves.

Thus, we are all the more grateful to our customer Maiko, who was able to successfully use the [product sku="2456460"] with his Mewlon 180 C and gave us feedback on his setup. We thank him for the information and would like to briefly present the required parts here.

At the Mewlon 180 C, he used:

  • [product sku="2458130"]
  • [product sku="2456005"]
  • [product sku="2456313A"]
  • [product sku"=2456314Z"]
  • [product sku="2456460"]

Takahashi Mewlon 180 C with MaxBright II Bino-Viewer

Of course, it is not just a matter of adapting the bino viewer mechanically, you also have to come into focus – on the Mewlon, the 1.25x glass path corrector is sufficient for this. Another advantage of a glass path corrector: it picks up the light beam "further back" in the telescope, where the beam of light is narrower, so that vignetting is avoided.

And how does it work under the night sky? Here, this combination fulfills the expectations, as the following observation report proves.

We thank Maiko for the information about the adaptation to the Mewlon and wish him many clear nights!

Observing with the Mewlon 180 C on the roof top. May 17th/18th 2023

Actually, yesterday would have been a much better night for the first deep sky session with the Mewlon 180 C: My SQM showed values of 21.2 to 21.3 MPSAS – and that on the roof top in the middle of a small town! The Milky Way was clearly visible and structured, which corresponded probably to a good Bortle 4 sky.

Well, I had to use the following night: The SQM showed 20.6 MPSAS, the Milky Way was barely structured, slightly blurred, probably between Bortle 4 and Bortle 5.

MaxBright® II Bino and Rigel Quickfinder at the Mewlon 180 C

For moon and planets, I tested the combination of HEQ 5, Mewlon 180 C and the Baader bino-setup, consisting of MaxBright II, BBHS T2 prism, 1.25 x GPC, ring dovetail and heavy-duty changer a few times. With the Panoptic 24mm and the Nagler 12mm T4, which were modified to 1.25", there were good to very good moments for observing the moon. During the brief moments of good seeing, the view is breathtaking. Unfortunately, I have been waiting in vain for good seeing (lasting longer than a few seconds) so far this year. Last August and September I had conditions that made for wonderful Jupiter and Saturn observations (at that time still monocular), also from the roof. Saturn appeared almost like in a photo at 240x in the 9mm Nagler, at about 20° height above the horizon. Several years before, I had a spectacular view of the moon with the Mewlon in April at 180x: contrast and sharpness were overwhelming, the image as if cut out... so I hoped that this spring the seeing would play along... well, maybe when the morning visibility of Saturn and Jupiter begins.

After setting up the telescope and finishing the polar alignment, I wanted to start with M3, but had no success. So I tried M13 and struggled, until finally I had it in the eyepiece. Why? Because of GoTo-refusal or purism...

To be able to use the setup binocular and without GoTo, I had to solve some problems. When pointing the telescope to a new object, the system must be in good balance, because the clamps are loosened. But this only works if the bino is always in the same position. I decided to align it to the axles of the mount. But this blocks the 30mm finder. I roughly locate the object in the Rigel finder I have attached. Then I clamp the axles. Now the bino can be carefully rotated into observation position. The Mewlon viewfinder can then be used for more precise adjustment, with corrections made via the motors.

This works fine for moon and planets, but I would not recommend this method for deep sky objects. Besides the usual observing problems, the limited visibility of the objects in the mewlon viewfinder and the necessary bending of your body to look into both finders cause lots of frustration when you have to guess in the Mewlon's viewfinder in which direction the invisible target has to be moved relative to the invisible crosshairs by the tracking motors which move only at snail's pace.
Ready to go: Monocular and binocular configuration

You're better of searching the objects monocularly with a long focal length 2" eyepiece, so that the object is in the field of view when switching to the bino-viewerrn.

Well, M13 was a delight in the binoviewer at about 110x: A quite dark sky background, and countless little stars in a cluster. At 220x the image naturally became quite dark.

M92 was a dream. I caught myself saying: "What a cute little bunch." On the same telescope, 220x was more usable, but not really good either. I mean, this magnification is better suited for the moon and planets in nights with really good seeing.

For a higher magnification in the bino-viewer, which is for medium seeing or brighter deep sky objects, I will probably try 16/17mm eyepieces, as 16mm will give you about 169x...There was something very touching about being able to enjoy M92 resolved into stars with both eyes almost meditatively on the roof garden of my small town at 3 o'clock in the morning.

The Mewlon is best known as a telescope for planets, but I encourage you to try bright, compact deep sky objects.

Monocularly, I had beautiful observations of M13, M92, M57 and the Eskimo Nebula in the Mewlon under a medium Bortle 4 sky.

Bino-viewers are also often praised for planetary and lunar observation.

Here, too, I recommend trying brighter deep-sky objects at the Mewlon. It can be very rewarding.

Since I am observing without GoTo, it is important for me to be able to quickly switch between the bino viewer and a 2" eyepiece to find objects more easily. I have now found a working combination for this too:

Mewlon 180 C on HEQ 5 in tracking-only mode monocular vs Baader Planetarium Maxbright II

It seems that my Mewlon setup is now ready to suit my observing style.

My equipment:

  • Mewlon 180 C upgraded with Rigel Quickfinder
  • ScopeStuff FineFocusKnob
  • mirror diagonal Televue Everbrite 2“
    • LVW 42mm, Nagler 22 T4, Nagler 12 T4 eyepieces
  • Baader Planetarium Maxbright II Bino-viewer, GPC 1,25 x, Zeiss Heavy Duty Quick Changer, T2-BBHS Prism
    • Panoptic 24mm eyepieces and Nagler12mm T4, modified for 1,25“

First night, June 11th, 2023, starting shortly after midnight:

My goal with the Mewlon was to find a solution to be able to quickly switch between mono and bino observations. On the one hand, I want to be able to observe optimally adapted to the conditions, on the other hand, I want to give fellow observers the option of going the "easier" way of monocular observation, and then to be able to observe effortlessly with a bino-viewer. In addition, I have developed the ambition to find objects in the classic way without a goto-mount with the setup described and to be able to observe either monocularly or binocularly.

The observation site is my small-town roof garden, which provided me several nights of very good seeing.

At dusk, I set up my telescope relaxed in a T-shirt – tt must have become summer... I used the Kochab method to polar-align the telescope. I used the the Celestron power tank as power source. My first object was M13. I found it quite easily with Rigelsucher and the LVW 42 eyepiece. Then I switched to the bino: M13 was beautiful to see for a short time, then fog moved in. The focus difference between mono ans bino is noticeable, but far from dramatic. In all configurations I reach focus effortlessly.

I paused, relaxed, looked a few times through the telescope. Eventually the fog cleared and I looked for M13 again. At 113x it was quite respectable in the 12mm Nagler. In about 30 minutes, the cluster remained reasonably in the centre of the field of view, which speaks for an acceptable polar-alignment.

M3 was a bit harder to find, but finally I succeded. Not very impressive at 113x and quite low in the sky...

On the other hand, M92 was a beauty: resolved into fine stars in the bino-viewer, again at 113x. It is wonderful to be able to experience this from the roof at home! Only a welcome-back-party of the neighbours distracted me a little.

After a break, I tried my luck at Saturn. Around 3:30 it was a little over 15° high above the horizon, of course still too low. But still it was quite pleasant at 113x, with a few quiet moments every now and then. Then I bravely tried the 12mm eyepieces at 225x. Surprisingly, there were quite passable phases despite the bad seeing. Cassini division, ring shadow, and colours of the cloud bands were well visible. I'll get back to Saturn when the conditions are better. Saturn was one reason to use a bino-viewer with the Mewlon. Oddly enough, at 225x it didn't seem that big to me.... if only the seeing was a bit more reliable...

All in all, it's a successful start. It's wonderful what is possible when using both eyes and combining Takahashi and Baader.

Every now and then I read about back-focus problems. I would like to encourage you to find out on your own Mewlon whether it is possible to successfully use a bino-viewer, and also use it for deep sky.

It seems to work very well for me.

Maiko

What do you look for in an astronomical filter? Everyone has different requirements and goals and with a myriad of filters available today; how do you choose the right filters to unleash the full potential of Astrophotography?

In this blog our customer Ian Aiken gives some high level advice on what to look for when choosing a filter, coupled with reasoning why he choose the Baader's CMOS-Optimized LRGB and Ultra Narrowband f/2 filters, along with example LRGB and SHO images taken with these filters on his Celestron RASA 11 from his Bortle 7 suburban location.

New CMOS-optimized Baader filters

Blog Post by Ian Aiken:

I live in the North East of England in the United Kingdom, which experiences a temperate maritime climate characterized by mild summers and cool winters. Cloudiness can vary throughout the year and it feels like I only get 20 usable clear nights per year at my Bortle 7 location during the 6 months where astronomical darkness actually occurs. I've been an Astrophotographer for over 20 years and I've had all kinds of telescopes, mounts, filters (including Optolong, Astro Hutech, Chroma, Baader) and cameras (Atik, QHYCCD, ZWO, Canon) in this time, for both planetary and deep sky photography. Financially, I've learnt the hard way through fine tuning my current collection to something which supports my sky conditions, budget, time, and imaging goals.

Currently I own a Skywatcher EQ8 mounted in my roll off roof observatory. On this I have a RASA 11 with Baader UFC, QHY268M camera and Baader's CMOS-Optimized LRGB and Ultra-Narrowband f/2 filters.

Here are the factors I've considered when choosing my filters:

  1. Price:
    Assess the price of the product in relation to its features, quality, and performance. Is the price reasonable and competitive compared to similar products in the market? Consider whether the product offers significant advantages or unique features that justify its price.

    In my opinion, Baader filters are absolutely value for money. They've kept the price competitive and performance high. A set of Baader filters costs a little more than a single Chroma. Chroma are good, but did not feel value for money in comparison (Baader 2" LRGB set ~ € 500 vs. Chroma LRGB ~ € 2.238).

  2. Quality:
    Examine the quality of the product. Does it meet your expectations in terms of durability, craftsmanship, and overall build quality? A product that is well-made and built to last will provide better long-term value.

    Baader CMOS-Optimized filters come with Baader Planetarium's Life-Coat technology. Baader warrant the coatings for the life of the filter guaranteeing that the coatings will not peel, flake or physically degrade and they have no issues with you cleaning the filters with fine optical cleaning equipment. You can see the build quality is high, the coatings look durable, and I can understand how Baader can offer such a life time warranty. I don't think anyone else offers this.

  3. Performance:
    Evaluate how well the product performs its intended function. Does it deliver the expected results or fulfil your requirements? Consider its efficiency, accuracy, reliability, and any additional benefits it provides compared to alternative options.

    I'm going to post some images later in this blog, and you can judge the quality for yourself. Yes, there were initial problems with halos and these have been resolved. I haven't had any issues that I am concerned about. Halos can be a real pain, and it's not always the filter that causes this (most cases it is not the filter). Reflections can occur in your imaging system and could be caused by a number of factors: including spacing between optical elements; distance to CMOS camera; the CMOS camera front window itself etc. You have to spend time to understand your entire optical system and its individual nuances.

  4. Features and Specifications:
    Review the features, specifications, and capabilities of the product. Are there any unique or advanced features that differentiate it from competing products? Determine whether these features are essential to your needs and whether they justify the price.

    I opted for high-speed ultra-narrowband to match with my RASA 11. This was based upon my needs (explained a bit further below). In terms of features, what stood out was the features integrated into the filters to help prevent reflections and halos. For instance:
    • Reflex-Blocker - with coatings to reduce halos caused by my imaging system.
    • Parfocal - this helps to not have to refocus so much during a filter change. As a filter change is manual on my RASA 11 with the Baader UFC system, it means less movement with my motorised focuser and I am back to imaging quicker (and the focuser isn't off on some mission to reach focus by going further out of focus, which can happen when using an SCT type design).
    • Blackened edges - again to help reduce reflections in my imaging system, lots of mirrors and glass = high potential for reflection
    • Sealed Coating Edge - each filter is coated individually and not cut from a sheet. This is probably why they will last forever, and Baader are able to offer Life-Coat warranty.
  5. Brand Reputation and Customer Reviews:
    Research the brand's reputation and customer reviews of the product. Look for feedback from other customers who have used the product to gain insights into its performance, reliability, and customer satisfaction. Positive reviews and a strong brand reputation can indicate better value for money.

    Baader Planetarium have been in business since 1966. I've never experienced any poor customer care from dealers or Baader directly (I admit, I've not really had any issues either, with exception of one issues with the early Baader Steeltrack software which was swiftly resolved by Baader themselves). As a family run business, I feel they are passionate with what they do, and want to do the right thing at the right price, making astronomy accessible to all budget types, and truly are Aiders in Astronomy (this is their slogan).
     
  6. Longevity and Future Compatibility:
    Consider the product's longevity and future compatibility. Will it remain relevant and usable for a reasonable period? Assess whether the product is upgradable or compatible with future advancements or technologies to ensure its value over time.

    I have the older Baader 2" CCD filters which are in the same condition that I purchased them in. I have no concerns about the longevity of the Baader CMOS Optimised filters, especially backed by the Life-Coat warranty. 2" filters are going nowhere, and while the sensors on modern CMOS cameras are getting larger, I cannot see the need to upgrade anytime soon. I've been using 2" filters for the past 20 years.
     
  7. Warranty and Customer Support:
    Evaluate the warranty offered by the manufacturer and the availability of customer support. A reliable warranty and responsive customer support can provide additional value by offering peace of mind and assistance in case of any issues or defects.

    Baader offers Life-Coat, a lifetime warranty on their CMOS-Optimized filters (providing used and handled correctly). As a family run business operating for over 50 years, Baader are trustworthy and offer great customer support.
     
  8. Personal Needs and Preferences:
    Finally, consider how well the product aligns with your specific needs, preferences, and intended use. Different products may cater to different requirements, so it's essential to choose one that best suits your circumstances and priorities.

What did I choose?

I decided on the Ultra Narrowband High-Speed filters on my RASA 11. Why? Well, the reasoning may surprise you. While the filters are excellent value for money, my garden backs onto other gardens and my neighbours have lots of LED lights lit, especially on weekends when it's not windy, the moon is not out, and the sky conditions are good. You can picture the challenges already. Also, there are trees which do not belong to me which get in the way. I work full time, and have two small children, time is limited. I'm middle-aged, but not retired, so I cannot stay up all night imaging into the early hours. So, I went for a RASA for high speed imaging, reducing my imaging time significantly. While I may image across multiple nights, I don't need to. It just works for my current situation. The Baader filters are brilliant on the RASA 11, and I'm able to produce some excellent results (see further in the blog) even with all my challenges.

I hope the above helps you make a decision on what filters would be good for your needs. Baader Planetarium has a really nice tool to help you match which filters would be best for your imaging system. At time of writing you can access this tool: Baader Narrowband-/Highspeed Filter Selector

Example of Astrophotography taken with Baader CMOS Optimized Filters

I could talk about how tight the stars are (they are), how the filters have much more contrast than their predecessors (they do), but this can still be very subjective and influenced by sky conditions. My skies aren't great, they really aren't, and I have to battle with all the other issues living in a suburban environment. These images were also shot in reasonably poor conditions with thin haze. I also have to point out that I don't spend a massive amount of time processing my images. I think partly, if you capture good data you can produce a good image. You don't, in my opinion, need to push an imagine in processing so that it looks so bright and colourful. To me this looks over processed, and I prefer the darker looking style images with simple histogram and curves transformations. There's the disclaimers out of the way.

M45 taken with Baader CMOS-Optimized LRGB

My workflow consists of using PixInsight to Calibrate, Stack, Automatic Background Neutralisation, BlurXterminate, NoiseXterminate, and maybe StarXterminate. I may use TGV Denoise post stretching but haven't on these examples. I simply use the ScreenTransferFunction (STF) in PI applied to the Histogram, and a hint of Curves Transformation before exporting off into a PNG/JPG. There's probably so much more I could do, but I don't. Oh, I nearly forgot. I do use PhotometricColorCalobration in PixInsight, which applies a white balance to the image.

NGC 7023 - The Iris Nebula 2 hour integration from Bortle 7 sky

NGC 7023, also known as the Iris Nebula, is a captivating and visually striking celestial object located in the constellation Cepheus. This reflection nebula lies approximately 1,300 light-years away from Earth, and its unique features have made it a favourite target for amateur and professional astronomers alike. The Iris Nebula gets its name from the distinct shape and appearance of its central region, which resembles an iris or an eye. This prominent feature is created by a dense cloud of interstellar dust, which scatters and reflects the light emitted by nearby stars. The dust particles in the nebula also create intricate dark filaments, adding to its overall visual allure. At the heart of NGC 7023 lies a young star cluster, illuminating the surrounding gas and dust with its intense radiation. This interaction gives rise to the vibrant hues of blue and yellow seen in many astro photographs of the nebula.

Imaging System: QHY286M CMOS Camera mounted on RASA 11 with Baader UFC.
Filters: Baader CMOS Optimised LRGB
Mount: Skywatcher EQ8
Exposure Details: 30 x 60 seconds each channel (LRGB).  Total 2 hours integration time from Bortle 7 skies.

NGC 7635 - The Bubble Nebula 17 Hour Integration from Bortle 7 Sky

NGC 7635, famously known as the Bubble Nebula, is a captivating and visually stunning emission nebula located in the constellation Cassiopeia. Its unique structure and distinct appearance have made it a popular target for both amateur and professional astronomers. The Bubble Nebula derives its name from the spherical bubble-like structure at its center, which is created by the powerful stellar wind and radiation emitted by a massive, hot, and young central star. This star, known as BD+60 2522, is estimated to be several times more massive than our Sun and emits intense ultraviolet radiation, which ionizes the surrounding hydrogen gas. The ionized gas then emits light, creating the striking reddish glow seen in images of the nebula.

Imaging System: QHY286M CMOS Camera mounted on RASA 11 with Baader UFC.
Filters: Baader CMOS Optimised 3.5/4nm f/2 Ultra Highspeed (Ultra-Narrowband) filters.
Mount: Skywatcher EQ8
Exposure Details: Ha: 354x60s, SII: 121x60s & 104x120s, OIII: 175x120s. Total ~17 hours integration time from Bortle 7 skies.

Don't ask why the varying exposure! I'd also like to collect more data on SII and OIII in due course given it's about half of what I planned and need. You can tell by the images more is needed. Maybe next time, right? Astrophotography is for life not just for Christmas, or something like that…

I mixed the combination using PixelMath in PixInsight.

And finally to finish off, M45 taken with Baader CMOS-Optimized LRGB on same kits as above.

M45 taken with Baader CMOS-Optimized LRGB

The Universal Filter Changer (UFC) system with its solid mechanics and high flexibility has found a large user base worldwide. Nevertheless, there are always applications that are not covered by the adapters available to date. Therefore, we receive requests for technical drawings from our customers again and again. In the course of further development of our products, we are now pleased to be able to provide the UFC Design Guide.

This design guide contains technical drawings with all the relevant dimensions you need to make your own adapters for both sides of the UFC - be it S70 ring dovetail connection on the telescope- side or the eyepiece/camera-side adaptation:

UFC Design-Guide: Camera-side UFC adapter
Download as PDF

UFC Design-Guide: Telescope-side UFC adapter
Download as PDF

This means that you can now easily design your own adapters for the UFC system and thus implement individual solutions for your special requirements.

We created this small design guide because of the following review by one for our customers. This is a good example of how your feedback and customizations help us continuously improve our products.

He published a very positive review of our UFC system, which highlighted the solidity and flexibility of the UFC system, but also his need for special adaptations, which motivated us to publish these drawings. Our customer has already created his own adapter using our design guide and kindly provided us with pictures as well as his self-created CAD drawings and documentation for it (without warranty), which we are allowed to share here. He himself writes about it:

My new adapter is an off axis guider for the UFC with M68 connection. It is supposed to connect the 2 1/2" corrector of my selfmade Newton (M68 mount) to the UFC and the camera without mechanical compromises. Another design criterion was to realize a clear aperture as large as possible to minimize the vignetting of a full format sensor. Since I had already made very good experiences with a homemade off-axis guider with an M48 connection, I used the Baader information on the UFC to make an M68 off-axis guider with a UFC ring mount that has the required length for my image train. As prism I used a simple 8x8 prism from Chin.

Kai Wickerphotonenfangen.de

We encourage you to share your similar projects and customizations with us and our customers. Your feedback helps us to continuously improve and enhance our products.

Thank you for your support and trust in Baader Planetarium.


Notice: Trying to get property of non-object in /home/baadercom/public_html/blogs/wp-content/themes/fishpig/local.php on line 458

This summer we provided our customer Mr. Rüdiger Proske with the new [product sku="1363080"] for a comparison test with the longer TZ-4. Most interesting was the question how the TZ-4S, which was primarily designed for the SunDancer II H-alpha filter, harmonizes with his large SolarSpectrum H-alpha filter. We are very happy about his very positive conclusion and his field report.

Please read the detailed report of Mr. Rüdiger Proske here:

In June 2023 I was offered the opportunity to test the new "Baader SunDancer II Telecentric System TZ-4S" (short TZ-4S) for the upcoming market launch.

Since I had already been working with the classic, long telecentric systems TZ-4 and TZ-3 for 2 years, my interest and curiosity for this TZ-4Short were immediately aroused. I wanted to know how the new system had developed and how it compared to the older TZ-4. It was also very interesting to see how the TZ-4S, which was primarily designed for the SunDancer II H-alpha filter, would work with the SolarSpectrum filter, which was used here.

The test setup

The new TZ-4S was tested on a TEC 140 ED with a native focal length of 980mm in front of a SolarSpectrum Solar Observer 1.5 - 0.5A H-alpha filter. To get the refractor to the necessary focal length aperture ratio of F=30, the TZ-4S is ideally suited. The achieved focal ratio of F=28 is sufficient.

A camera with a Sony IMX174LLJ was used as sensor, which is particularly suitable for solar images due to the global shutter. A Baader D-ERF was mounted in front of the telescope lens to keep the energy out of the telescope.

Unboxing and mechanical impression

The TZ-4S comes in a small, Baader-typical cardboard box. When you hold it in your hands, the TZ makes a solid and robust impression. Spontaneously, one is reminded of an eyepiece, and it can be mistaken for one at first glance. Although it is completely made of metal, it is a bit lighter with approx. 250g than the old system with approx. 310g.

What immediately stands out positively is the compact and short design compared to the significantly longer old system. The satin black surface seems to be identical to that of an eyepiece and promises longevity. Both ends are securely closed by dust caps.

Integration into the image train

On the telescope side, the TZ-4S is inserted into the eyepiece clamp like a 1.25" or 2" eyepiece. I use a 2" Baader ClickLock eyepiece clamp. This allows for quick setup and offers the ability to rotate the H-alpha system as needed.

On the camera side, the TZ-4S has a T-2 thread. This makes it easy to adapt standard components such as T-2 extension tubes or quick-changer. But also an integration into the Baader M68 Tele-Compendium is possible. A minimum of 100mm after the last lens element is specified as backfocus. The distance is usually achieved with T-2 extension tubes. Here I have made the experience that it is quite beneficial to the image quality to increase the distance a little. In the end, I found about 150mm to be optimal. However, the system is very tolerant, as is typical for a TZ (in contrast to Barlow lenses).

The short backfocus is a significant advantage over the old TZ-4, which required at least 240mm as working distance. This significantly reduces the enormous length that an H-alpha setup has. This reduces the load on the focuser and reduces the risk of a mechanical collision during meridian flip.

The entire assembly proved to be mechanically robust with no play or "wobble".

Optical performance

As always, pictures say more than a thousand words. Therefore, I refer you to the pictures below. Visually, however, it can be clearly said that the new system is at least equal, if not superior, to the old one. A direct comparison at Lucky-Imaging is always a bit tricky, since conditions are constantly changing and ultimately a statement is always based on the "stacked" images. However, what I could determine in a direct comparison is that the new TZ-4S was consistently a tad sharper and the images had more reserves in terms of dynamic range. This is probably primarily due to the recalculation of the optical setup and the H-alpha wavelength optimization, which pays off here. 

Size comparsion old and new TZ-4(S) at the telescope

Conclusion

The new "Baader SunDancer II Telecentric System TZ-4S" is a wonderfully compact and high-quality telecentric system that feels at home on both small and large telescopes. Its connection options allow for versatile use. And when stowed away, the system takes up no more space than an eyepiece.

To me, the new TZ-4S represents a consistent and logical evolution of its several-year-old predecessor.

Pros:

  • Compact
  • Relatively light
  • Robust
  • Standard connections
  • Very short working distance for TZ systems

Cons:

  • None found in two weeks of use

Notes:

  • The test system was provided on loan by Baader Planetarium. Many thanks for this!
  • The system was not tested with the SunDancer II, but with a SolarSpectrum.
  • More pictures and solar animations from the author: https://www.astrobin.com/users/DarkStar/


Notice: Trying to get property of non-object in /home/baadercom/public_html/blogs/wp-content/themes/fishpig/local.php on line 458

Our customer Mr. Karrer uses the [product sku="2301003"]. With his fantastic images Mr. Karrer proves that a SC telescope can keep up with the best refractors in solar photography. We are truely impressed – high-res images which compete with well-known professional observatories.

Read here the detailed field report of Mr. Michael Karrer about the Baader Triband SC 9.25":

I own the Baader 9.25 triband SC telescope now since august 2022, but I'm still not using it often enough. Last May, a calm weather phase was coming and I decided to to start working later in the morning than usual and take a look at the sun instead. Visually, there were no air turbulences visible in the small Lunt H-Alpha telescope, the image was "steady". Accordingly, I had high hopes for the camera view through the 9.25" Triband. For the first time I used the 3x Baader SunDancer telecentric system which I had just bought, which allows a quite short image train. Because everything had to go quickly, I saved myself the warm-up phase of the Solar Spectrum H-Alpha filter and used the etalon of a PST instead. The image on the monitor was the steadiest I have ever experienced! And that at around 7 m focal length! Not much later, I had the AVI data on the hard disk. "Autostakkert" selected the best zones as usual.

I compared my results with (the few) top solar photographers who work with refractors with up to 9" aperture: Details with the Triband-SC are at least on the same level, if not even better to recognise! A sensational result for me! A large refractor costs a lot, is heavy, is hardly transportable and requires a massive mount. With the "feather weight" of an SC, all this is no longer necessary.

Let these pictures be the prove that an SC telescope can keep up with or surpass the best refractors in solar photography (be sure to look at the photos in full resolution).

 And if you don't know it better, you sometimes do things which are "forbidden": I also used the Triband to take pictures in white light, together with the Baader Solar Continuum Filter. The image looked quite dull, but the details were good. The image processing was challenging. It was only afterwards that I discovered the now available Triband manual on Baader's website. The Triband-coating blocks the wavelength of the Solar Continuum Filter – hence the pale image! I should have used an OIII filter. Depending on the focal length extension, the sensitivity of the camera or even the transparency of the sky, a photographic Baader film or the Baader Herschel wedge may be necessary for further light attenuation.

How much of an issue is the obstruction of an SC compared to a refractor? It does reduce contrast, I can see that when I compare the image with that of my refractors. But image processing with dedicated contrast enhancement largely makes up for this disadvantage.

My conclusion:

Highest resolution, that's the goal. With the compact design of an SC, there is also the elegant option to observe at places with better chances for good seing seeing. Because only there can the optics unfold their true potential – and that is amazingly high! A refractor of the same size, on the other hand, will suerly stay at home...

Michael Karrer
www.flickr.com/photos/michael_karrer

The new QHY 5-III-715 Color of the 2nd generation is an affordable solar, lunar and planetary camera and at the same time a perfect guiding module for extremely short focal lengths.

General description of the QHY 5-III-715 Color

QHY 5-III-175C

[product sku="1931038"]

The QHY 5-III-715 Color is now the 4th camera of the 2nd generation of lunar and planetary cameras with integrated SBIG ST-4 guiding port. The advantages compared to the 1st versions of this camera series are among others:

  • Large internal 512 MB DDR3 image memory
  • Improved front-end design
  • Compatibility with CS and C-mount lenses
  • LED for camera status indication
  • USB 3.2 Type-C interface[br]

The QHY 5-III-715 Color is an ultra-high resolution color camera with a very sensitive Back Illuminated Sony Sensor (BSI) while maintaining extremely low readout noise. The new USB 3.2 interface allows frame rates of up to 42 frames per second at full resolution (lucky imaging for sun and moon), and significantly more for ROI (planets). Due to the extremely small pixel dimensions of only 1.45 µm x 1.45 µm, an imaging scale (image resolution) of about 1 arc second is already possible with focal lengths around 300 mm, so that reliable guiding is easily possible with focal lengths around 200 mm.

Some highlights of the camera

Lunar, planetary and guiding camera: QHY 5-III-175C

Lunar, planetary and guiding camera

  • Sensor: Sony IMX715 BSI sensor - only available as color version
  • Pixel size: 1.45 µm x 1.45 µm
  • Number of pixels: 3.840 x 2.192 (5.6 x 3.2 mm) - 8.4 MegaPixel
  • Readout noise: 0.87e- to 2.17e-
  • Full well capacity: 5.7ke-
  • Maximum frame rate: 42 frames per second at full resolution
  • Exposure times: 11µs - 900 seconds[br]

Extended sensor sensitivity in the near infrared spectral range (NIR)

Similar to the [product sku="QHY5III462C"] the new [product sku="1931038"] also features extended sensitivity in the near infrared spectral range.

In this latest generation of Sony sensors, the photodiodes are embedded deeper in the substrate than in previous sensors, allowing photons with longer wavelengths (NIR) to penetrate deeper into the substrate. This dramatically increases the sensor's sensitivity to red and near-infrared light. The peak sensitivity (quantum effectiveness) of the sensor in the NIR spectral range is almost as high as for light in the visible spectrum.

All further information and the technical data of the new QHY 5-III-715C can be found on our prodcut page.

The [product sku="2458170"]

The M68 system allows for a sturdy and rigid connection of heavy accessories. The M68 tilter is a relatively recent addition to this family of adaptors and was developed to easily compensate for image tilt in an optical train through simple adjustments of three pairs of easily-accessible (even when a camera for example is attached) hex-screws located around the edge of the adaptor. Although the M68 tilter itself is small occupying just 9.50-10.25mm of optical path length, and relatively light weighing in at just under 100g, it can accommodate a heavy accessory payload of up to 5kg. The tilter allows a tilt shift of up to 1° to compensate for misalignments in the image field.

Baader M68 Adapter with M68-Tilter + UFC for the QHY600M camera
Baader M68 adapter with M68-Tilter + UFC for the QHY600M camera.

The M68 tilter has been used successfully on a Celestron EdgeHD 14” with a 36.3MP DSLR and a 61MP CMOS camera to achieve round stars edge-to-edge. A review of the M68 adaptor can be found on AstroGear Today's website.

Other "members" of the Baader tilter-family include the UFC tilter and the FCCT (Filter Changer Camera Tilter) forr RASA 8" and QHY cameras. You can read more about these here.[br]

The T-2 and M48 adaptations for cameras and accessories are still widely popular and we have been often asked whether (and how) the M68 Tilter can be used with these systems. The answer is YES the M68 Tilter can indeed be used with T-2 and M48 accessories and below we show you how. At the moment we have no plans to introduce a smaller T-2 or M48 tilter as the larger size of the M68 unit allows for fine tilt adjustments and also can accommodate a larger accessory payload too.

[br]

T-2 Accessories

Lets begin by looking at the T-2 system first. The T-2 system is still widely used and there is a wide variety of cameras having T-2 (female) connections and T-2 (male) fitting accessories.

M68 Tilter with parts for connecting to T-2 telescope and camera-side accessories

Starting from the telescope (left) side and moving (right) towards the camera side, we have the following adaptors in place:

Telescope or accessory with male T-2a thread :->

  • [product sku="2958242"]:
    The adaptor ring has an internal female T-2i thread (to screw onto the male T-2a thread of the telescope-side accessory) and has a 2"a external male thread. In other words it allows a male T-2a thread to be converted to a 2"a thread.
  • [product sku="2458232"]:
    Has an internal 2"i thread with an M68a external thread. With the above adaptor in place it will now convert the telescope accessory T-2a external thread into a male M68a thread.
  • [product sku="2458195"]:
    This converts the male M68a thread of the above #2458232 adaptor into a female M68 thread to allow attachment onto the Tilter's telescope-side M68 male thread.
  • [product sku="2458170"]:
    The M68 Tilter (external M68a thread telescope side ; internal M68i camera side)
  • [product sku="2458233"]:
    This two-piece adaptor steps down from M68 to T-2. The adaptor has external M68a threads to screw into the Tilter's M68i internal threads and has T-2 male threads on the camera side to attach to a T-2 accessory with female T-2 threads (e.g. camera). The adaptor, as whole, consists of two separate parts: [product sku="2458232"] and [product sku="1508035"].

-> fits to Eyepiece/camera side accessory with female T-2 thread (e.g. camera with female T-2 thread or T-ring)[br]

[br]

M48 Accessories

Let us now turn to the M48 system. As with the T-2 outline above, we will once again start from the telescope (left) side and move (right) towards the camera side. You will notice that there are a number of the same parts used as outlined for the T-2 adaptation above.

M68 Tilter with parts for connecting to M48 telescope and camera-side accessories

Telescope or accessory with male M48a thread :->

  • [product sku="2454834"]:
    This zero-length adaptor has an internal M48i thread and external 2"a SC thread to convert 2"i SC female into M48i female. This will attach onto an M48 accessory with a male M48 thread. As this zero length adaptor is very thin we suggest it be attached to the male M48 accesory first.
  • [product sku="2458232"]:
    Has an internal 2"i thread with an M68a external thread. With the above adaptor in place it will now convert the telescope accessory into a male M68 thread.
  • [product sku="2458195"]:
    Converts the male M68a thread of the above #2458232 adaptor into a female M68 thread to allow attachment onto the Tilter's telescope-side M68 male thread.
  • [product sku="2458170"]:
    The Tilter unit - which has an M68 male thread on the telescope side and M68 female thread on the camera side.
  • [product sku="2458229"]:
    A single-piece step down adaptor with a male M68 thread on the telescope side to screw into the M68's female thread and has a male M48a threads on the camera side to attach to an M48 accessory with female M48i threads.

fits to -> Eyepiece/camera side accessory with female M48-thread (e.g. Camera or M48 adaptor with female M48 thread).

M68 Tilter used with a DSLR and the Baader M68 Quick Changer

It may be that your imaging train uses both M48 and T-2 accessories, for example an M48 male thread accessory on the telescope side and a camera with a T-2 female thread. In this example this is easy to accommodate. Looking at the first T-2 diagram you would simply replace the first (in-line) telescope-side T-2 adaptor (#2958242) for the [product sku="2454834"] which would attach to the M68-2"UNFi conversion ring (#2458232; used in both configurations) and then use the remainder of the adaptors in the T-2 sequence. If you require to use spacer/extension tubes (e.g. for use with reducers etc) you could select one of the fixed or the variable extension from the M68 series and the Baader M68 Quick Changer to use on the telescope side of the tilter (e.g. see image opposite).

Please note: With the Baader family of tilters, the whole "tilt adjustment operation" can be achieved without imaging train removal. Tilt adjustment is performed using three pairs of opposing set screws, on the tilter's outside edge, which independently move the inner tilt mechanics. These hex screws have tapered and hardened points that bear against a precision hardened ‘zero-clearance’ internal steel-counterpart. The direction that each set screw moves the tilter is shown with a helpful etched arrow next to each individual adjustment screw. You can read more on how to finely adjust tilt with the UFC-, M68- and FCCT-Tilters in an article here.

QHY461M PH, BSI Mittelformat Kamera, gekühlt

[product sku="1931294"]

The QHY461 PH (photo) is a monochrome BSI CMOS camera with 102 MegaPixel, 16bit AD conversion, highest quantum efficiency with extremely low readout noise.

New - especially for amitious amateur astrophotographs -

The monochrome QHY461M PHis a completely new development of the larger, scientific camera of the monochrome model QHY461M-Pro. It has a more compact body and does NOT have the scientific features of the  [product sku="qhy461"]. These include the two 2 x 10 GB fiber interfaces, GPS timing, programmable FPGA and the external trigger input. An optional additional water cooling is also not available.

Data is transferred to the PC via a standard USB 3.0 interface. Otherwise, the performance of the QHY461M PH is essentially identical to the scientific version. The main advantage of the QHY461M PH is that it offers all the features and performance important for astrophotography at a much lower price than the QHYM 461-Pro.

Die Daten werden über eine Standard USB 3.0 Schnittstelle an den PC übertragen. Ansonsten ist die Leistung der QHY461 PH im wesentlichen identisch mit der wissenschaftlichen Version. Der Hauptvorteil der QHY461M PH besteht darin, dass sie alle für die Astrofotografie wichtigen Funktionen und Leistungen zu einem deutlich niedrigeren Preis als die QHY461M Pro bietet.

The Sony BSI CMOS IX 461 sensor

The Sony BSI CMOS IX 461 sensor

High-resolution, scientific CMOS sensor Sony IMX 461 with 102 megapixels

The Sony IMX 461 is a BSI Exmore R sensor with similar architecture to its bigger brother, the IMX 411. The sensor measures 44mm x 33mm with a 55mm image diagonal. The array has 11,656 x 8,742 pixels (102 megapixels) at 3.76 µm square pixels. It has maximum quantum efficiency while maintaining high dynamic range.

True 16 bit analog digitization with 65,536 gray levels

The IMX is the world's first scientific CMOS sensor with the AD converter "on board". The data output provides true 16 bit with 65,536 gray levels. Compared to cameras 12/14 bit sensors, the QHY461M PH offers higher sampling resolution and the system gain is less than 1e-/ADU with very low readout noise.

Very low readout noise of only 1 electron with high gain

The QHY461M PH has only one electron readout noise (1 e-) at high gain and a high - for the large dimension of the sensor - readout speed of 1.3 frames per second (fps) at 16 bit, or 2.7 frames per second at 8 bit AD conversion.

Quantum efficiency and low dark current noise

The IMX 461 sensor's BSI technology results in exceptionally high quantum efficiency (max. 90% at 540nm) and features extremely low dark current thanks to SONY's Exmor BSI sCMOS technology. This means that the camera's high sensitivity and low readout noise make it suitable not only for short exposures, but also for long exposures, where dark current noise often dominates.

The quantum efficiency of the IMX 461 as a function of wavelength.

The quantum efficiency of the IMX 461 as a function of wavelength.

Full well capacity of 50 ke- in standard mode and up to 720 ke- in extended mode

Another advantage of the BSI CMOS structure is the increased full-well capacity. This is especially important for sensors with small pixel dimensions. Even with unbinned 3.76 µm pixels, the QHY461 photo has a full-well capacity of 50 ke-. When binning 2x2 to 7.5 µm, the full-well capacity is already 204 ke- and when binning 3x3 to 11 µm, it is 408 ke-. As a further technical highlight, QHY461M PH offers 4 different readout modes of the sensor, including an extended full-well mode. In extended mode, the full-well capacity is 80 ke- unbinned, 320 ke- binned 2x2 and 720 ke- binned 3x3.

Pure raw data

Many DSLR cameras have RAW image output, but it is usually not entirely in RAW format. Upon closer inspection, some traces of noise reduction and hot/coll pixel removal are visible. This can have a negative effect on the image in astronomy. However, the QHY461M PH (and also the other QHY models with 16 Bit AD conversion) provides REAL RAW IMAGE OUTPUT and produce an image consisting only of the ORINAL SIGNALS of the individual pixels, maintaining maximum flexibility for astronomical imaging programs and other scientific imaging applications.

Anti-dew technology and amplifier readout glow

The QHY461M PH's technology is based on nearly 20 years of experience in developing cooled CMOS cameras and provides solutions for icing and dew control. The optical entrance window has a built-in heater to protect dew condensation on the entrance window and the sensor chamber from internal moisture condensation. The sensor itself is kept dry with our desiccant tube base design to control humidity in the sensor chamber. The QHY461M PH shows no amplifier readout glow even with long exposure times.

Advanced high-tech features

Restarting the camera with power on/off

The camera's electronics are designed to use the +12V power supply to reboot the camera WITHOUT having to disconnect and reconnect the USB interface. This means that you can restart the camera by simply disconnecting the +12V and then reconnecting it. This function is absolutely essential for remote operation of a telescope! You can simply use a remotely controllable power supply to restart the camera.

Random thermal noise suppression function

Certain types of thermal noise can change over time in BSI CMOS cameras (keyword: the aging of electronic components). As a result, each image has a unique thermal noise characteristic, making it difficult to reduce by subtracting a dark image.

The QHY461M PH employs innovative proprietary technology that significantly reduces the amount of random thermal noise.

Optimizing USB speed to minimize horizontal banding

CMOS sensors usually show some horizontal banding (see figure below). Usually, these random horizontal bandings are removed by adding multiple raw images so that they do not affect the final image.

However, the so-called periodic horizontal banding is not removed during stacking, so it may be visible in the final image. By adjusting the USB transfer speed in single image or live image mode, the user can adjust the frequency of the CMOS sensor driver, optimize the transfer frequency and thus suppress the horizontal banding.

Left, an example of typical periodic horizontal noise at standard USB transmission frequency. On the right after optimizing the transmission frequency with strong reduction of banding

Left, an example of typical periodic horizontal noise at standard USB transmission frequency. On the right after optimizing the transmission frequency with strong reduction of banding

The most important technical data of the QHY461M PH:

  • Sensor: Sony BSI IMX 461,
  • Sensor resolution: 102 megapixels with the pixel size 3.76 µm x 3.76 µm
  • Sensor size: 44 x 33 mm, sensor diagonal 55 mm
  • AD conversion: unaltered, true 16 bit (65,536 grayscale)
  • Read noise: 1e- to 3.7 e- (depending on readout modes)
  • Data interface: USB 3.0
  • Full well: up to 720 ke- depending on readout mode with high dynamic range
  • Quantum efficiency: max. 90% at 450 nanometers
  • Dark current noise: extremely low
  • Amplifier glow: not available
  • Noise reduction: user selectable
  • Image readout: 4 different modes, user selectable

Here we describe in detail the advantages of the modern Sony IMX 461 CMOS sensor in comparison with a CCD sensor, which was for years the first choice in amateur astronomy imaging.

{{block type='core/template' blockpost_id=17334 template='gammafx/planetarium/wppost.phtml'}}