October 24, 2021: Attempt at M31 with the Sigma 120-300 F/2.8

[michael.h.f.wilkinson]

Clear skies at last, so I thought I would go for an easy target in M31. I thought I would have a test of the Sigma 120-300 mm F/2.8 Sports lens I have, with the Canon 550D for easy of attachment. I got a fairly bright star lined up quite easily, focused in live view, and then did a first test shot.

After some head scratching and swearing, checking the mount for issues, it finally dawned on me that I had left the lens as it was used for sports photography, so image stabilization and AF where still switched on. After setting both switches off, I did some test shots at full aperture, but these were not that encouraging in the corners, so I went for F/4. I got some 120 subs at 60s ISO1600, and stacked the results in APP (with flats, darks and dark flats)

The upper left corner is still not good. Bit of a pity, as the lens is very fast. Maybe a smaller sensor like the ASI183MM or ASI294MM will fare better

 

 

[callisto]

Nice image 

 

Mark