M31

[JohnC64]

Hi All,

Now M31 has ben a nemesis of mine since i started in Astrophotography. I could never get an image that I was entirely happy with. At last I feel I've started to make some progress on this one. 20x3minute subs with a IDAS filter 135mm Lens on Canon 1100D. The Filter does make a huge improvement. I've added a couple of subs with and without the filter to show the difference. Captured with Nebulosity & PHD, Stacked and DBE'd in PI and Levels, curves etc in Gimp.

Cheers John

Processed Image

No Filter

With Filter

[ian_bird]

Wow - that filter is earning it's keep!!!!

Nice one John.

Cheers

Ian

[nmoushon]

Thats a great start! I would add another hour or two...or more if you have the time. I think you will be super happy with what you can achieve. Make sure to grab a couple 30 or 60sec subs for the core. Once you start to really stretch the image you will want those so you don't burn out the core.

[ian_bird]

Does Gimp do layers like PS does? If so - you don't need short exposures for the core. Just have two layers - high stretch for the outer arms on one layer, shallower stretch for the core on a second layer. Then erase the first layer over the core to allow the second layer through.

Allegedly.

Cheers

Ian

[nmoushon]

Does Gimp do layers like PS does? If so - you don't need short exposures for the core. Just have two layers - high stretch for the outer arms on one layer, shallower stretch for the core on a second layer. Then erase the first layer over the core to allow the second layer through.

Allegedly.

Cheers

Ian

Layers don't work like that. Yes you can no stretch as much for the core but the core is still burnt out to begin with. Not as much as a final stretch without layers but you still loose some of the inner detail. At this wide FOV you might be able to get away with that but I can't with my ED80 at 400imm ish. Maybe I'm a bit of a perfectionist but I want as much detail as I can get.

[JohnC64]

Thanks all, Yes more subs is the way to go on this (True for most things APwise :-) ). Cheers John

[Quatermass]

looking good there John, your dead right M31 is a strange beast to image I always found the hard part was capturing the very faint outer edges of the galaxy. Stacking about 80 subs with a good mix of shorter subs for the core was my method of choice when I had the ed80. I hope to get a new skywatcher 130pds soon and will have a crack at it with that. Nice job.

[ian_bird]

Quote on

Does Gimp do layers like PS does? If so - you don't need short exposures for the core. Just have two layers - high stretch for the outer arms on one layer, shallower stretch for the core on a second layer. Then erase the first layer over the core to allow the second layer through.

Allegedly.

Cheers

Ian

Quote off

Quote on

Layers don't work like that. Yes you can no stretch as much for the core but the core is still burnt out to begin with. Not as much as a final stretch without layers but you still loose some of the inner detail. At this wide FOV you might be able to get away with that but I can't with my ED80 at 400imm ish. Maybe I'm a bit of a perfectionist but I want as much detail as I can get.

Quote off.

Ahem!

Olly and I. Processing by Olly.

Cheers

Ian