H-alpha Accessories

Please take a look at our Digiscoping-PDF at https://www.baader-planetarium.com/en/downloads/dl/file/id/444/product/1210/digiscoping_camera_adaptations_for_afocal_photography_and_eyepiece_projection.pdf where we describe several options to attach a camera or video module.

You need some distance between camera and eyepiece to avoid distortions at the edges; but with a smaller sensor, you can get closer. You'll usually achieve higher magnifications than with a Barlow lens; the formulas for calculating the effective focal lengths are inside of the PDF.

For large sensor and really high magnifications, we recommend the FFC # 2458200

Probably...

If you want to equip any 2" star diagonal with a ClickLock, you can always use
Baader 2" ClickLock 37 mm extension #2956237
or
Baader 2" ClickLock 47 mm extension #2956247

If you want to replace the nosepiece of a star diagonal with this nosepiece, it depends on the star diagonal. If you can remove the original nosepiece and if you can then access a female SC-thread (2" 24 GZ 60°), then you can replace one nosepiece with another - although this shouldn't make too much of a difference?

If you can remove the clamp of the star diagonal and can then see a male 2" SC thread, you can use the Baader 2" ClickLock SC/HD (2") clamp (C5" - C9¼") #2956220 to replace the original clamp.

This depends on the adapter... If your Sony M48-adapter is *not* a slim version, but instead provides the standard distance of 55mm between flange and camera sensor, then you need an additional 1.5-3.5mm of distance (57.5 +/-1mm is the optimum).
You can achieve this e.g. with M48 finetuning rings:
https://www.baader-planetarium.com/en/m48-fine-adjustment-rings-(03--05--1-mm)---aluminium.html
The preferred 2.5mm could be reached with two 1mm and one .5mm ring.

For the QHY with its smaller sensor, you can use the T-2-thread. To achieve the desired 55mm, you need 9mm +/-1 with the autoguider.
You can create a 10mm-extension (which is close enough) from
Baader T-2 Conversion (Ring T-2 Part #: 34) # 2958110
and
Baader T-2/T-2 Inverter Ring (T-2 Part #: 26) # 1508025

For the QHY without the autoguider, you can use
Baader VariLock 29, lockable T-2 ExtensionTube 20-29mm with spanner tool (T-2 part #25Y) # 2956929
and set it o 22mm.

Yes, this is possible as can be seen on these images:
https://www.baader-planetarium.com/media/extendware/ewimageopt/media/inline/ac/1/baader-zero-tolerance-protective-canon-dslr-t-ring-t-2-m48-and-2-49c.jpg
https://www.baader-planetarium.com/media/extendware/ewimageopt/media/inline/6f/7/baader-zero-tolerance-protective-canon-dslr-t-ring-t-2-m48-and-2-858.jpg

The Alan Gee was designed for an ideal working distance of 121mm from the Alan Gee to the camera sensor/eyepiece at a classic Schmidt-Cassegrain. But you can also use it at different distances; 193mm e.g result in a focal ratio of f/3.5 - which of course compresses the usable image circle more, too.

The back-focus of an SC of about 146mm is the distance from the telescope's rear cell to the focal plane if there are no other lenses. If you use the Alan Gee, you place it in the desired distance from your camera (to achieve the desired compression ratio) and then focus with the telescope. Moving the main mirror changes the focal ratio of the SC, the data given in the manual refere to the resulting focal lengths when the Alan Gee is mounted as described in the manual.

But please note that the Alan Gee was designed years ago for Schmidt Cassegrains and not for the already flat field of an EdgeHD. For photographic use with an EdgeHD, we recommend the original Celestron reducers which were designed especially for the EdgeHD-optics.

The Alan Gee works fine with classic SCs, where it flattens the field and suppresses coma over a field of ca. 18mm - but with larger chips and smaller pixel sizes, this system is pushed to its limits. It is not recommended for pixel sizes smaller than 6-7my.

But for both EdgeHD and Schmidt-Cassegrains, the Alan Gee is a very interesting product for use with binocular viewers like the MaxBright II, because its working distance matches the back-focus of a binoviewer very good. Furthermore, the optical system of both Schmidt-Cassegrains and EdgeHD provides such a large back-focus, that the Alan Gee can almost double the field of view on most Celestron Schmidt-Cassegrains without visible vignetting. In the course of the development of the MaxBright II binoviewer, we have also developed a new T-2-cell for the Alan Gee. This new product - the AG Universal II - is designed for visual use with binoviewers and works even a little bit better with EdgeHDs, as they have a longer back-focus.

The AG II Universal as special reducer for binoviewing (but not for photography) will come to the market some months after the MaxBright II. If you are interested in binoviewing, we'd recommend not to buy the standard Alan Gee, because it deosn't offer the same connection options as the Alan Gee Universal. The Alan Gee Universal will be mounted directly between the binoviewer and the T-2-star-diagonal. We are looking forward to present this new product in 2020.