Swapping between eyepieces: The useful Baader Q-Turret Four Eyepiece Revolver

The planets Saturn, Mars, Venus and Jupiter are making an appearance in our morning sky making a lovely photogenic celestial lineup. About an hour before sunrise you can see the magnificent ringed gas-giant planet, and second largest planet in our Solar System, Saturn towards the south east with our red coloured neighbour Mars sitting below and to the east of it. Venus is next in line shining brightly at magnitude ~4.2 and is exhibiting a gibbous phase and very low near the eastern horizon is the largest planet Jupiter. These planets will make their way to being evening objects later in the year becoming better positioned where they will be observable for longer. Our Moon is easily seen throughout most of each month so its a frequent and easier object for observation and/or imaging.

 

Planetary observers are likely to own a number of eyepieces, changing between them to get differently magnified views of our Moon, the planets (and many deep sky objects). Owning multiple eyepieces comes with a few "associated issues". One is of course having to physically remove and safely store that current eyepuece, and then locate another eyepiece and insert it in your focuser and refocus if necessary. Its also important to think about where to store the (unused) eyepieces in the interim - on a table or in a box or storage case for example.

Wouldn't it be useful to have a device that holds a number of eyepieces you would most often use so switching between them is so much easier and more convenient? Enter the Baader Q-Turret Four Eyepiece Revolver.

The 1.25" Q-Turret 4-Eyepiece Revolver

The Q-Turret 4x Eyepiece revolver (#2957010 , € 55,-) is an accessory that helps you quickly and easily swap between eyepieces - or between eyepieces and a small imaging camera without having to remove, store and then insert a new eyepiece in the telescope's lightpath.

With the Q-Turret you can select up to four 1.25" eyepieces (or three eyepieces and a small imaging camera) you want to use at the telescope. The turret is designed to be used with low weight small eyepieces such as Plossls or similar (see below) rather than larger heavier optics. Next, place them in the Q-Turret's eyepiece holders and use the knurled locking screw on the side of each eyepiece holder to secure them in place. Insert and secure the turret's 1.25" nosepiece into your focuser drawtube and then revolve the turret to select which eyepiece you want to be in the telescope's light path. Its that simple. The unit features a simple but firm "click stop" so you know when an eyepiece reaches the correct position in the telescope's lightpath.

How to organise the eyepieces in the revolver is down to personal choice. For example you could organise eyepieces in structured way of decreasing focal length (increasing magnification) as you rotate the turret clockwise (or anticlockwise) from the initial lowest power eyepiece so that you know how the view will change.

The Q-Turret accessory is not a bulky accessory - it has a small form factor. It is quite compact and fits nicely in the palm of your hand measuring only 120mm in diameter (outside of barrel to outside of opposite barrel). The Q-turret is also not very long and adds only ~38mm to the path length (i.e. moves the eyepiece out by this amount) so can be used in a wide range of telescopes.

To keep the overall weight low and cost affordable, the turret is made of strong but durable plastic and as a result only adds just under 100g to the telescope.

The example set up shown in the image to the right consists of the Q-turret along with a Celestron’s 40mm E-Lux and 13mm Plossl, Baader Genuine Orthoscopic eyepiece and a Celestron Skyris planetary imaging camera where the overall weight of this visual/imaging setup comes in at just under 520g.

The Q-turret and Eyepiece and Barlow Package

In addition to the Q-Turret being available as a stand-alone accessory, it is also available as part of a complete visual eyepiece and barlow package: Baader Q-Turret Eyepiece Set (eyepiece revolver, 3x Classic Ortho, 1x Classic Plössl, 1x Q-Barlow 2.25x) (#2957000 , € 280,-)

This set comprises the following high quality components

• three 1.25" 6mm, 10mm, 18mm classic Orthoscopic (Ortho) eyepieces,
• a 32mm classic Plossl eyepiece,
• a 2.25x barlow lens
• the Astro (storage) Box #1.

This set is ideal for those who want a complete and versatile Lunar and planetary observing accessory package "out of the box". Let's look at the package contents in a little more detail.

Classic Eyepieces

Orthoscopic eyepieces are often the eyepiece of choice for many Lunar and planetary observers with their very high image quality and sharpness. The Baader Classic Ortho eyepieces are available in focal lengths of 6mm, 10mm and 18mm. One of the first things to notice is how light they are weighing in from just under 40g for the 6mm classic Ortho up to just over 90g for the 32mm Classic Plossl. Although their low weight may make you think their optical quality is low, they use the same glass and triplet element-plus-one plano-convex eye lens optical design as the old Orthoscopic eyepieces that were produced by Zeiss Jena - a good sign of high quality! In fact the Q-Turret and eyepiece set was reviewed by Sky and Telescope in their October 2013 issue and was selected as one of their Hot Products for 2014!

The Classic Ortho eyepieces each have a 52° apparent field of view, with the 32mm Plossl having ever so slightly less at 50°. All of the range are parfocal meaning that when you switch between the different Classic eyepieces no, or very little, focus adjustment is needed. Each lens features sharp field stops, and to maximise light throughput and minimise internal reflections High-Transmission Multi-Coatings (HT-MC) are applied on all the glass-to-air surfaces. The eyepiece bodies also have blackened interiors for stray light suppression and maximum contrast. The 1.25" eyepiece barrels are threaded to accept standard 1.25" filters to help with Lunar and planetary observation (e.g. 1.25" Six Colour Filter Set - Moon and Planetary). All four eyepieces are supplied with rubber removable winged eyecups (also available separately - in case of the need for a spare or a replacement: Baader Classic W Rubber Eyecap with folding wing (#2454652 , € 10,-) ) which are ideal to help keep stray light out (e.g. Moon glow or a neighbours outside light) when viewing which also helps improve the view. The winged eyecups are easily be folded back leaving a flat surface which may be suitable for some (e.g. glasses wearers).

The magnification and field of view you will get with these eyepieces all depends on the telescope being used. Schmidt-Cassegrain telescopes are good all-rounders for those wanting to view and image the Moon and planets as well as deep sky objects too. The image (right) shows the simulated field of view and magnification you will get (using Stellarium) with our Moon, a popular celestial target, with the 32mm Classic Plossl (top left) and clockwise the 18mm, 10mm and 6mm Classic Ortho eyepieces.

Below is a table with some more details about these Classic eyepieces.

Focal length (mm)	Optical design	Barrel	Lens elements / groups	Apparent field of view	Parfocal	EyeRelief	Field stop	Height	Outer Diameter	Weight
6	Classic Ortho	1¼”	4 / 2	52°	yes	5mm	5mm	34.2mm	34.8mm	37g
10	Classic Ortho	1¼”	4 / 2	52°	yes	8mm	8.7mm	41.12mm	34.8mm	48g
18	Classic Ortho	1¼”	4 / 2	52°	yes	14.67mm	16.8mm	54.46mm	34.8mm	81g
32	Classic Plössl	1¼”	4 / 2	50°	yes	21mm	26mm	78.8mm	34.8mm	94g

 

 

 

 

 

 

 

 

The 2.25x/1. 3x Q-Barlow Lens

The inclusion of a barlow lens extends the packages' usefulness as it will give an additional range of magnifications with the supplied Classic eyepiece set. The barlow is unique in that it gives a higher 2.25x image amplification rather than the usual 2x that the vast majority of other barlows offer. As with the Classic eyepieces, the Q-barlow features blackened interior and High-Transmission Multi-Coating on all air-glass surfaces for maximum light transmission and extremely low internal reflections.

Out of the box, the Q-Barlow has a 1.25" nosepiece and accommodates 1.25" accessories which are secured in place by a simple lock screw. The Barlow lens cell can also be unscrewed from the main body and be directly threaded onto the nosepiece of the Q-Turret. When used in these configurations the barlow gives an image amplification of 2.25x and 25mm image circle.

 

 

The removable barlow lens cell housing features a male M28.5 filter thread which means you can also screw the Q-barlow lens cell directly into the Classic eyepiece barrels or fully into a 1.25" imaging camera threaded nosepiece. If you use the barlow in this fashion the image amplification is 1.3x and, for imagers, the barlow gives a full un-vignetted image circle of 13mm. The barlow lens can also be used in the same manner with other 1.25" eyepieces with filter threaded barrels although the image amplification may be slightly different.

The table below shows the focal lengths of the Classic eyepieces with their resulting focal lengths with the Q-Barlow in its 2.25x and 1.3x configurations. If we list the eyepiece focal lengths in increasing magnification with the 2.25x barlow in use they are:

32mm --- 18mm -- 14.2mm  -- 10mm -- 8mm -- 6mm --- 4.4mm -- 2.7mm

As shown above there is a good spread of focal lengths and therefore magnifications.

Classic Eyepiece Focal length	Focal Length 2.25x Barlow	Focal Length 1.3x Barlow
6mm	2.7mm	4.6mm
10mm	4.4mm	7.7mm
18mm	8mm	13.8mm
32mm	14.2mm	24.6mm

 

Storage container: Baader Astro-Box #1

Nicely completing the Q-turret, four eyepieces and barlow lens package is the Case: Astro-Box#1 (M31) with window (#2957005 , € 12,-) (this is available on its own too!). This small container is ideal for safely transporting and storing these accessories. The box is made of aluminium, has internal foam insert for added protection for storage and transportation, features a window (so you can see whats inside) and is decorated with a nice image of the Andromeda Galaxy adorning its lid.

QHY-5-III-462C Planetary-Bundle (VIS/NIR) with complete Q-Turret Eyepiece Set

The Q-Turret package is also available as a bundle with the QHY-5-III-462C Lunar and Planetary camera (Planetary-Bundle (VIS/NIR) with complete Q-Turret Eyepiece Set). This package is ideal for those interested in combining visual Lunar and planetary observation with some planetary imaging.

The bundle comes with all the items mentioned above, in addition to the QHY-5-III-462C colour Lunar and planetary imaging camera, 1.25" UV/IR Cut filter, 1.25" 850nm IR Pass filter, parfocalising focus lock ring, ST-4 compatible autoguiding cable and USB3.0 data/power cable.

The 462C features an uncooled 1920x1080 pixel CMOS colour sensor with 2.9micron square pixels and a high maximum full frame rate of 135 frames per seconds (higher if using a smaller ROI [Region of Interest]). The sensor, a back-illuminated Sony IMX462 CMOS, has very low read noise making it ideal for stacking very large numbers of frames to produce a cleaner final "stacked image" and also has high sensitivity in the visible 400-700nm range. Furthermore the sensor's structure increases its sensitivity in the red and Near InfraRed (NIR) portion of the spectrum and this is shown in the sensor's spectral response graph. For those wanting to do something "a little different" by imaging the planets with a Methane filter ( Baader Methane-Filter 1¼" (889nm, 8nm) (#2458295 , € 239,-) ) which can reveal for example cloud structures on Jupiter, this camera is ideal.

The sensor and its electronics are housed in a long tubular 1.25"-sized barrel body so it can easily slide into a 1.25" focuser - or in this case into the Q-Turret or the Q-Barlow. Four larger diameter "fins" near the rear of the camera help with heat dissipation (and also could stop the camera falling into a telescope too!). The camera comes supplied with a parfocal lock ring which slides on the camera nosepiece body. Once you have your object in view and focussed with one of the Classical eyepieces rotate the turret to bring the camera into the telescope's light path. With the camera operating through the QHY (or other) software hold the parfocalsing ring against the body of the Q-turret or focuser and slide the camera in and/or out until the image is sharp and then tighten the ring's lock screw. The camera and the eyepieces are then all parfocal requiring none or very little refocusing. Switching between eyepieces and the camera is therefore a very quick, simple and straightforward procedure.

Power and data transfer is via USB3.0 with the USB port on the rear of the camera so no additional power lead is necessary helping with clean cable management. In addition to planetary imaging, the 462C can be used for guiding. The rear faceplate has a 6-pin connector that allows the supplied standard RJ11 cable to be used with mounts featuring an autoguide port.

The images to the left are simulated views from Stellarium of Saturn (left) and Venus (right), which are currently visible in the morning sky through a Celestron 8" f/10 SCT with the 462C camera.

For both, the image at the top is without a barlow, with a 2x barlow (middle) and at the bottom with the Q-Barlow at 2.25x amplification. The result of the extra magnification of the 2.25x barlow over a 2x model can easily be seen.

 

Final Thoughts

As someone who owns a large range of different eyepieces, I often use the Q-Turret in its purely visual configuration when observing the Moon, planets and even the Sun (with appropriate solar safety equipment such as AstroSolar Safety Film). Being able quickly swap between eyepieces is such a benefit and I find its small size and low weight ideal especially if I am using portable "grab and go" telescope and mount. If you already have a range of suitable eyepieces the Q-Turret on its own is an ideal accessory. If you want to expand your eyepiece range for Solar system observation the affordable complete Classic Eyepiece and Barlow kit is perfect. For those who want to additionally delve into Planetary and Lunar imaging the Visual and Imaging Planetary Bundle is well worth considering.

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About the author: Lee Sproats

Dr. Lee Sproats has been interested in astronomy since watching Star Wars in 1977 and has appeared on the UK Sky at Night TV programme. He then went on to study Astronomy where he obtained a degree and then a PhD in the subject at University College London/Mullard Space Science Laboratory. He has worked in Australia in radio astronomy and used optical/infrared telescopes on Hawaii and La Palma and Lowell and Kitt Peak observatories in the USA. After working for the University of Surrey to promote the use of computers for teaching in UK higher education and then as an IT trainer for a stock market company, he went on to work for Greenwich Observatory Ltd where he ran their northern branch and then worked for David Hinds Ltd dealing with our and Celestron products. He is often involved in flight excursions that take passengers to observe the northern lights, has led trips to see the great USA 2017 eclipse near Hopkinsville and was lead astronomer onboard a specially chartered 737 to view the 2015 total solar eclipse at 38,000ft. Lee`s astronomical interests include Lunar observing, astrophotography, photometry and pro-am collaborations.

Since David Hinds stopped operation in December 2020, Dr. Sproats works for Baader Planetarium as our UK representative/consultant and is responsible for looking after our UK/Eire dealers, dealing with Baader Planetarium/PlaneWave/10Micron product support, writing articles and also is involved in our large telescope and observatory instrumentation projects.

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