Equipment

# The 890 mm focal length is well-suited to the pixel size of the Starlight cameras. If needed, the focal length can be doubled using a Vixen converter.

# The image field shows no significant coma up to the MX7 chip size; a corrector is only required for the SXV.

# The fiberglass tube has low thermal expansion, so even multi-hour exposures without refocusing are no problem.

# However, due to the large aperture ratio, precise adjustment is necessary after each setup. The tube also weighs a good 20 kg, but the Gemini mount has handled this, including the 15 kg counterweights, without any issues so far.

# The Gemini was a real eye-opener after the Vixen GP. High positioning accuracy, no backlash in RA and hardly any in DEC. The periodic worm gear error is within the specified range of +/- 5 seconds.

Equipment
It all started in 1998 with a used C8 telescope on a Vixen GP mount with a SkySensor 3D. Instead of the wooden tripod, a homemade tripod made of square steel tubing was used for CCD imaging, which significantly improved stability. I spent many hours minimizing the backlash in the spur gears and worm gear. However, the simple mechanism couldn't be adjusted below approximately +/- 50 seconds. This, of course, had consequences for positioning and tracking accuracy. But with patience and practice, it worked reasonably well. Next, the counter from a 10-turn potentiometer was mounted on the focusing knob, which greatly simplified focusing with a Schreiner mask or diffraction spikes. Finally, a dew shield made from camping mat was added, and the telescope tube was insulated with heating foil. A Celestron F6.3 and a Meade F3.3 focal reducer make the telescope quite versatile. The mount, tripod, and Skysensor have been sold for some time, but I couldn't part with the C8 for a long time; it has quite good optics, see NGC6543.	C8 on Vixen GP with the Skysensor 3D controller (sold)
In 2002, I bought a used Parks 10" f/3.5 Newtonian telescope from Gido Weselowski. He had even used it to discover the two galaxies Weselowski I and II. The Parks had previously belonged to Rainer Mannoff, who had demonstrated its capabilities in wide-field deep-sky photography. The Newtonian is mounted on a Gemini 40 mount controlled by a FS2 controller. The entire setup is supported by a heavy, height-adjustable Spindler-Heuer tripod. Thanks to a number of advantages, this setup was my preferred workhorse for a long time: # The 890 mm focal length is well-suited to the pixel size of the Starlight cameras. If needed, the focal length can be doubled using a Vixen converter. # The image field shows no significant coma up to the MX7 chip size; a corrector is only required for the SXV. # The fiberglass tube has low thermal expansion, so even multi-hour exposures without refocusing are no problem. # However, due to the large aperture ratio, precise adjustment is necessary after each setup. The tube also weighs a good 20 kg, but the Gemini mount has handled this, including the 15 kg counterweights, without any issues so far. # The Gemini was a real eye-opener after the Vixen GP. High positioning accuracy, no backlash in RA and hardly any in DEC. The periodic worm gear error is within the specified range of +/- 5 seconds. So far, I have had no complaints about the mount. The FS2 works flawlessly, is easily controlled via PC, and is efficient to use. Only the PEC function still doesn't work with the Gemini. However, since I generally use an autoguider or self-guider, this is less important. In 2022, a Skywatcher EQ6R was added, which now also enables automated meridian flips. The Gemini remains in use for the heavy Parks Newtonian telescope and is now controlled by an OnStep controller, which also allows for meridian flips.	Parks 10"/F3.5 on the Gemini 40 with the FS2-controller
In 2003, I bought a used C5 on a Nexstar mount from Peter Bresseler for use as a travel telescope. I will also test its suitability for wide-field astrophotography; the test report indicates good optics.	Celestron C5 on a Nexstar-mount.
New since September 2004: The William Triplett APO 80/480 with TMB optics. It was supposed to offer a larger and higher-quality image field for CCD images than the C8 with a focal reducer. The first CCD images were disappointing, and the lens was sent back for inspection in January 2005. Apparently, the lens became warped at temperatures below 10°C. Markus Ludes promptly replaced the lens. Since then, this little instrument has been a great pleasure to use, both photographically and visually.	Wiliam Triplett APO 80/480
The first attempt to create a mosaic with the SXV and the 80mm William, and then the use of the ALCCD6 with the larger chip, made it clear that this would not work without a field flattener. The TS flattener proved extremely effective here, as the adjacent excerpts from the corner of the ALCCD6's field of view demonstrate.	Image corner of the ALCCD6 in the William APO 80/480 without flattener	Image corner of the ALCCD6 in the William APO 80/480 with flattener
In the spring of 2005, I acquired the Takahashi CN-212 from Helwig Fülling. The concept of this reflector is compelling: by changing the secondary mirror, this instrument can be operated both as a classic Cassegrain at f/12.4 and as a Newtonian at f/3.9. The TAK was intended to replace the 10" Parks and the C8. The Cassegrain mode proved its worth immediately; despite the often mediocre seeing at my location, small deep-sky objects can now be imaged well. The Newtonian mode, on the other hand, consumed a considerable amount of time during collimation. Ultimately, however, it worked out – my expectations were met. That said, achieving a clean collimation is significantly more complex compared to the Parks, and image distortions are much more pronounced when deviating from the optimum.	Takahashi CN-212. Sold 2011.
In the spring of 2011, I purchased the 10" RC telescope new from Wolfi Ransburg. It was first checked and readjusted by Wolfgang Rohr. Rohr attested to its exceptional quality: "Up to a field diameter of at least 21 mm, even the critical test of Artificial Sky at 1000x magnification shows clearly defined points that can demonstrate the possible resolution of 0.55 arcseconds up to a diameter of 21 mm."	GSO Ritchey-Chrétien 10" F8 on Wolfgang Rohr's optical bench.
At the beginning of 2014, a new, slightly larger Triplett APO from TS was added to the collection. Equipped with a 2.5" flattener and an additional 0.79x reducer. Testing by Wolfgang Rohr showed that I had once again been lucky – an excellent instrument for photography: "An impressive 'flattener' with a SUPER image field: TSapo130S + TSFlat2.5".	Triplett APO 130mm F7
My first CCD camera was a Starlight Xpress MX5c. I definitely wanted to shoot color images, and the MX5c promised a relatively inexpensive entry point. For that purpose, the camera was quite good, but it soon no longer met my growing demands. In particular, the limited 12-bit dynamic range proved to be a hindrance to optimal image processing of faint objects.The MX cameras' inherently effective self-guiding option and the minimal effort required to acquire color images then prompted me, after two years, to purchase its larger sibling, the MX7c. With increasing skill and demands, the MX's readout noise and the frequent uncertainties in color synthesis led me to purchase an SXV-H9 with a Naumann filter wheel and a separate guide scope (C5) in 2004.	SXV-H9 - my third camera from Starlight Xpress. Sold.
My initial attempts to capture large objects using mosaic techniques weren't particularly successful. Therefore, I decided to use a cooled CCD camera with a larger chip. For price reasons, and to avoid the compromises of uncooled chips in EOS cameras, I opted for the ALCCD6 (=QHY8), a 6 Mbit camera with an APS-C chip size. Initial images yielded good results. While the noise is higher and the quantum efficiency lower than with the SXVH9, it doesn't suffer from the color synthesis and amplifier noise issues of the MX7c. Capture without a dark frame or flat field is easily achievable, and the Ha sensitivity is good. The ASTROART plugin works flawlessly. Nevertheless, I haven't been able to establish an image processing workflow that consistently produces satisfactory results. Uneven intensity distributions in the RGB channels, in particular, have often been a problem. So I decided to switch back to a black and white camera with a larger sensor (Atik 383L+).	ALCCD6 (=QHY8) APS-size color chip Sold 2012

Return to black and white photography: I bought the Atik383L+ at the end of 2012 for two reasons: 1) to have a larger sensor compared to the SXV 2) because of the tried and tested KAF8300 sensor. On Wolfi Ransburg's advice, I opted for the slightly smaller 383 instead of the ATIK4000. This saves additional effort in avoiding vignetting caused by filters, guiders, etc. The 80 mm secondary mirror of the Parks 10" Newtonian telescope couldn't stay – it was replaced with a 104 mm mirror.	The ATIK383L+ (KAF8300 17.6 mm x 13.5 mm mono chip) Purchased in 2012, sold in 2022
The rapidly improving quality of one-shot color cameras and the ASIAIR mini-computers finally led me to purchase the ZWO 294MCpro and 2600MCpro cameras and the ASIAIR controller. This made the recording process very convenient and efficient, and the image quality improved significantly.	ZWO 294MCpro, purchased 2022	ZWO 2600MCpro, purchased 2024

Wide Field Photography After initial attempts with the Fuji X10 proved less than successful, I began exploring wide field photography with a Canon EOS 700D and 60Da. Under the superb skies of the semi-deserts in the southwestern USA, I was quickly able to capture successful images of the Milky Way. The Vixen Polarie also proved its worth for tracking at short focal lengths. The Samyang 14mm f/2.8 and 85mm f/1.4 lenses are significantly superior to the Sigma 18-200, which I use for daylight photography.	Canon EOS 60Da with Samyang 85mmF1.4 on Vixen Polarie Purchased 2017 Sold 2019
But soon, simply capturing the Milky Way wasn't enough for me, and my desire for longer focal lengths grew. Several attempts with travel-friendly mounts like the Skywatcher Star Adventurer, the Omegon Minitrack, and the AstroTrac TT320 didn't meet my expectations. Only the Chinese Strainwafe UMI 17L mount enabled me to take long-distance images that were in no way inferior in quality to those obtained with stationary mounts.	Travel mount UMI 17L

Location
All stationary images were taken on the balcony of our 250-year-old half-timbered house, about 15 km north of Freiburg im Breisgau. The tripod and mount usually remain in place, while the telescope is set up and taken down each time. The location is far from ideal – stray light from streetlights and neighbors, a severely limited view of the sky, and often requiring shooting over rooftops. Of course, there are better observing locations in the nearby Black Forest, but the effort is too great for me – after all, there's life outside of astronomy. The transparency is generally moderate, rarely better than magnitude 4, and the seeing is exceptionally good, sometimes reaching 2 seconds, but usually more like 3-4 seconds.	My "observation window", south is below