Where's M27 Gone

[JamesF]

This is another image I took with the SPC900 last night. I can see the dumbell is vaguely there in the centre, but it doesn't show up at all well. Is that just because it's very faint, or could there be other reasons it doesn't show up?

16x40s exposures, no darks.

James

[rfdesigner]

What focal ratio were you shooting at?

[JamesF]

I just had the webcam straight in the back of the ST120, so f/5. (ST120 on an unguided EQ3-2. I think all the other details are there.)

I'm wondering if I just need an awful lot more subs. I can't really take the gain down any further because I wouldn't even be able to see M27, but if I take longer exposures the stars will probably be blown out?

James

[rfdesigner]

I just had the webcam straight in the back of the ST120, so f/5. (ST120 on an unguided EQ3-2. I think all the other details are there.)

I'm wondering if I just need an awful lot more subs. I can't really take the gain down any further because I wouldn't even be able to see M27, but if I take longer exposures the stars will probably be blown out?

James

Ah!

you need to take short insensitive shots and long max sensitivity shots then sort it out in processing.

I beleive the webcam will be 8 bit output.. in which case you certainly need to do different shot types. On M42 many people use different shot lengths and then process them together and that's with 16 bit cameras and 12/14 bit DSLRs.

Derek.

[JamesF]

I think I might leave that for the moment then. I'm struggling enough with learning about the imaging side for the moment, without confusing myself with processing as well

James

[Chris]

Hi James, have you thought about getting a dslr body? it will make things a lot easier, you can pick up a Canon 300, 350D etc for about 100 quid.

[JamesF]

I have one. I'm starting simple

James

[rfdesigner]

James

I would just try a set of max sensitivty shots then. Give it a go, good luck

Derek