This image of M13 in Hercules is the "first light" for my new QHY268M camera paired with the Sky-Watcher Esprit 100ED refractor and Atik EFW2 filter wheel with 36 mm unmounted Baader filters. I did not have a chance to optimize spacers and check for tilt yet, but my initial guess was close enough that I may just live with it for a while. The trickiest part of setting up the gear was connecting the camera to the filter wheel, which required an Atik EFW2 to M54 male thread adapter that I had to order separately. It arrived 30 minutes before sunset on the first clear night I have had in a long time.
My worries about the camera and filter wheel being too heavy for the Esprit's stock focuser were unfounded, as I did not have trouble with the focus slipping, and if there is any flexure, it is minimal so far.
My first impression of the camera is that I am going to love using it. With the Esprit 100ED at the native f/5.5, it provides a spacious 145' x 97' field of view and 1.4" per pixel image scale. I don't see why I would need to use a focal reducer with this camera. So far, I have only tested Mode 1 (High Gain) with short exposures, and here is the result with Gain=56 Offset=10. The image is cropped as little as possible, but I lost a few pixels due to dithering.
This image was processed with GIMP as the main platform, as usual. I masked some of the brighter stars to avoid overstretching them. It is worth noting that several of the brighter stars were overexposed, even with 1 minute luminance subs and the large full-well depth of the sensor. Perhaps Mode 3 will be the go-to mode for images with bright stars in the future?
One other note on the processing is that I stretched M13 with the goal of fully resolving the stars without burning out the core. The cluster might be a bit too dim for some peoples' processing tastes.
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