Constellation: Andromeda
Telescope: Esprit 100ED with ASI2600MC camera
Autoguider: Williams Optics Uniguide 50mm with ASI120MM camera
Mount: Losmandy G11 with Gemini 2 mini controller
Controller: ASIAir Plus
Filter: UV/IR Cut
Location: Mid Pinellas County, Florida.
Bortle: 8+
Subs: 10 at five minutes each (50 minutes)
Processing: PixInsight
Comment: Mousing over the photo shows the Cepheid Variable star that in 1923 Edwin Hubble used Henrietta Leavitt's
technique to determine the distance to the Andromeda Galaxy proving that it was not a nebula in the Milky Way but its own galaxy.
This greatly expanded the known size of the universe.
This image isn't bad for 10 subs but there is a lot of detail that will show up with more data. This image is about the full frame of the Esprit
100 at 554mm with the APC-C chip size of the camera.
While I made a half-hearted attempt at astrophotography in the film area in the early 2000s using gas hypersensitized Tech Pan using an old Nikon F2 T-mounted to my C11. The results were mostly out of focus star trails. Digital astronomy cameras were available at the time but they were in the $5K and above price range for any quality and only a few megapixels. The good news is that I already had a fairly substantial tracking mount - the Losmandy G11. This was a 20 plus year old tracking but not a go-to mount. The good news for me is that the Losmandy mounts were designed to be upgradable. After changing out the stepper motors to servos and replacing the controller and a few other upgrades I now have a software controllable go-to mount that should be able to support a telescope and astro camera.
Reevaluating the camera options in 2022 opened a world of new manufacturers and options. One of the new players is ZWO. They make an ASI camera and accessory line of more than a dozen gray-scale and one-shot color cameras as well as autoguiders and other accessories. After some research I went with one of their APS-C cooled one-shot cameras for the main camera and a William Optics f/4 Uniguide scope with a ASI120MM 'mini' camera for the autoguider. Later that was upgraded to an ASI220MM camera. These are being controlled by a ASIAir Plus. When I added an electronic focuser that the ASIAir controls a lot of the tedium was eliminated from the process.
After all of the other pieces were working the limitations of the old Megrez 80SD doublet were really showing up in images. I decided to upgrade to a more modern triplet in the Esprit 100ED. Now everything was where I wanted it, except for clear skies.
If you go the ASIAir Plus route you need to use ZWO cameras for both imaging and tracking (or a ZWO camera that has a autoguider built-in) and a ZWO auto focuser if you want the ASIAir to control them. The mount may be most modern go-to mounts. Although I have a Pole Master I usually use the ASI Air Plus to get the polar alignment and control everything from an iPad. While ZWO offers a few ASIAir models the plus model has two USB3 ports which I wanted for the camera that also supports USB3.
ASIAir Plus Controlling the G11
My Losmandy G11 mount is from about 2003 and has been upgraded to the Gemini 2 system. Additionally it also has the latest Level 6 firmware upgrade.
I started off using a compass to rough align the mount to magnetic North. Then Pole Master was used to polar Align the G11. The G11 hand controller was used to star align and then letting the ASIAir's plate solving finish off the object targeting.
After some testing I now still use the compass for rough alignment. Then the ASIAir's polar alignment is used instead of Pole Master. I also no longer attach the Gemini's hand controller and let the ASIAir's Plate Solving take care of framing the target. Additionally the guide scope tracking is also handled by the ASIAir. I chose the ASIAir Plus because it had two USB3 ports that attach to the primary imaging camera and the guide scope camera. The two USB2 ports connect to the EAF (electronic focuser) and the G11 mount. If needed the primary camera has a built-in USB hub and two additional USB2 devices may be connected, like a filter wheel or camera rotator. For now I like connecting the tracking scope to the camera's hub with a short USB cord.
There are also four 12v power outputs (round 5.5mm x 2.1mm I believe). One goes to the primary camera and allows the built-in chiller and dew heater to work. Two of the outputs have software controllable PWM (Pulse Width Modulation from 0-100% power) on them and may be used with standard 12v Dew heater strips with an adapter to a female RCA plug. Both the guide and main scope's dew heaters are powered by the ASIAir Plus. All of the power outputs may be turned on and off via software.
The ASIAir is connected to my wireless home network and controlled by a tablet (Android or iOS). The ASIAir is an amazing and well thought-out piece of hardware and if you are using ZWO cameras, focuser, filter wheel I highly recommend it.
Cleaning the Camera Sensor
Although I try my best to keep the camera sensors clean dust seems to find them. Both my astro and DSLR cameras have had dust issues. It manifests itself as light toned circles on the images.
The ZWO camera comes with a metal screw-in dust cap with an o-ring seal. While great for storage it has to come off sometime. In my case that camera is attached to the filter drawer once the camera is on the mount. Before attaching the camera I check it inside with a flashlight at various angles to make sure that it is clean. Really clean. Spotless. Every tiny spec on the sensor shows up as a light circle on the image. Any dust at all requires a sensor cleaning. I try a squeeze blower first. Sometimes that's not enough.
There is a spec of dust in the center left of the sensor that could not be removed with the blower.
My cleaning supplies are a flashlight to check for dust specs, a sensor cleaning swab and Eclipse optical cleaning fluid. First turn off any fans and close nearby windows. You don't need new dust swirling around. Using some tape remove any dust from the black outer metal part of the camera (Not the sensor!) to prevent it from falling on the sensor later.
Remove the dust cap and place it face down on a dust free surface. Open the sensor swab and do not touch the swab's cleaning end. Put a few drops of the cleaning fluid on the swab near the end. Make a couple of wipes across the sensor the same direction for each the the width and height getting right to the edge. Do not blow on the sensor to dry it faster and never use your breath to blow on the sensor. Check for any remaining dust. The sensor should be clean. If not repeat the wipes, otherwise install the dust cap until the camera is mounted on the telescope.
The supplies to clean the sensor. I use Eclipse optical cleaning fluid and an APS-C sensor cleaning swab.
