Using the F/15 Maksutov as an astrograph

The F/15, 2700mm focal length 18cm aperture Maksutov is never intended to capture deep-sky images. Instead it excell’s at planets and the Moon.

However, with this focal length, it makes sense to give it a try at small objects like galaxies.

This is what came out of it, as a test, stacking 40 subs of 300s at gain 0. That’s 3 hours and 20 minutes. The detail is ok, what I noticed are triangular stars so I need to take a look at the collimation, seems to tight.

M66, Maksutov 180mm F/15 43x300s ASI2600MC

Compared to what my C11 did with an ASI183mm RGB last year:

M66, C11 F10 46x120s at G111 ASI183mm RGB

Testing the C11 without OAG

After cleaning & collimation, I tested the C11 with the Starizona F 7.2 reducer, the ASI183mm (way oversampled obviously), and guiding using a simple external 8×50 guider and the ASI290MC. Just as a test not bad. I’m not convinced the mirror shift did not have influence in this image. Focusing was a pain, needed to be done manually.

C11 Starizona F7.2 reducer flattener 8×50 guidescope, ASI183MM 46×120″ G111 Baader RGB