Nothing but Blobs

[robindurant]

I have been fairly sucessfull in imaging the Messiers 27, 57 & 82 together with clusters but have had no luck with M 31. The image below is 20 subs @ 45 secs on a clear night with the messiier at approx. 45o. I processed it on Elements3 but all I can get is a blob. I have tried 3 times now at other number of seconds with the same result, a blob. Every one was taken with my Canon 350D via my 8i on Prime Focus. ISO 1600. Can anyone help.

Robin

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[Astroman]

The problem here is image scale. You've only imaged the central portion of the galaxy, not the extents, so it appears as a blob. Since M31 is several times the diameter as the full Moon, you may not be able to image it whole.

Take a look at this image closely. http://stargazerslounge.co.uk/index.php?topic=7710.msg83287#msg83287 You can see the pattern of stars around your image very close to the center core of the galaxy.

[moondog]

Robin

I agree with AM.

Your 8i is has a 2032 mm focal length.

I imaged M31 earlier in the year with my TAL at prime focus with the 350D

The Tal has a 1125mm focal length and I still didn't get the extent of M31.

It takes my Revelation 80ED at 550 mm focal length to easily get M31 at prime focus.

Even a focal reducer on your 8i wouldn't help.

That's why a lot of SGL members have a second, smaller, refractor in the 450mm to 700mm range.

I presume you stacked the images before processing in PS ?

MD

[CELESCOPE]

Nothing more to add really , its all been said , its a huge Galaxy, and take a few more subs , 45 secs should be ok , try for 50 or more subs , not sure about elements i have it but never use it for stacking images in ,

Rog

[robindurant]

Thanks for your replies.

I use Deepskystacker to stack and Element3, which is a Adobe processing program like Photoshop.

I might try using my Celestron 102SLT, do you think that this could be better.

Robin

[moondog]

Robin

Don't know about the 102SLT's lens quality, but the 660mm focal length should show the extent of M31.

Give it a go, it'll probably be fine !

I also use Deep Sky Stacker and PS Elements 3.

MD