The weather at XX star party in Zatom was generally good however, some amount of high clouds was present all the time. But it did not prevent me from testing the Star Adventurer tracker mount, that I acquired some time ago. SW Sky Adventurer tracker mounts are well known among astrophotography amateurs and all kinds of tests and reviews were already performed. Adventurers are generally able to track 2 minutes subframes with lenses up to 100-135mm, and 90s frames with 200mm focal length lenses. These figures assume no guiding is used, the mount is not overloaded and 5-10% of the frames are trash due to elongated stars. But it is actually quite a lot of exposure time for modern CMOS sensor-based cameras. Due to low read noise in this type of sensor, the single subframe exposure time may be shortened without degrading of stacked image quality. Of course, the total exposure time must be quite long as well because the total exposure time determines the final image signal to noise ratio.
The setup I tested during the astroparty contained Sky Adventurer mount head with the wedge, Benro Mach 3 tripod (that proved to work in this role very well), and astro modified Canon 550D camera with Canon 70-200 f/4 lens. The camera was operated with the programmable release cable. I wanted it to be completely portable and battery-powered, but due to extensive humidity present in the air, I needed to equip the lens with a dew cap heater. There are heaters powered from portable power banks, but I did not have such a device yet, and I used a regular 12V heater with a power supply. The rechargeable battery in Canon is good for about 2-2.5 hours of exposures.
The first image covers the area in the border of Cassiopeia and Perseus constellations. This field is rich with clusters and nebulae, just to name a few of them: Cave, Bubble, Wizard, Lobster, Messier 52, but also several dark and emission nebulae as well. The second picture contains probably even more recognizable items: Gamma Cygni (Sadr) nebula and Crescent nebula, at the right well known double reflection nebula NGC6914, the lesser-known LBN218 reflection nebula at the middle-top, and many Barnard dark clouds and smaller emission nebulae.
The sky at this remote location was quite dark, so despite modest exposure times a lot of nebulosities were captured. However due to the presence of high clouds bright stars gained visible halos at the image, that is hard to completely remove during processing. Sky Adventurer proved to be able to take 90s subframes at 135mm focal length without any stress. More than 90% of frames were of good quality, and stars have no visible elongation. This Sky Adventurer setup with Canon 550D astro-modified camera is available to rent.
Full resolution media files:
https://astrojolo.com/wp-content/uploads/2020/09/2020-09-19-cassiopeia-2.jpg
https://astrojolo.com/wp-content/uploads/2020/09/2020-09-19-gamma-cygni-2.jpg
Image technical data: Date: September, 2020 Location: Zatom, Poland Telescope: Canon 70-200 @135mm, f/4 Camera: Canon 550D astro modified, ISO800 Mount: SW Sky Adventurer Exposure: 70x90s (Gamma Cygni) and 80x90s (Cassiopeia) Conditions: seeing medium, transparency good, high clouds
