Advise on Imaging Eagle nebula

[zakkhogan]

Hi all, ive been imaging with my cpc80 (no wedge),

I shoot a few frames of the eagle nebula at the end of a session the other night.

Without a wedge i can get 15 - 30 sec exposures, but i didnt get a hint of the eagle nebula.

it is quite possible that the scope just didnt centre on it, howerver my gut instinct is that M16 is just possibly too dim to capture in 15 sec exposure.

any thoughts?

Thanks

Craig

[badgers]

You'd be very hard pressed to catch much in 15 seconds on an unmodified camera. Depends on your f-ratio though, if it was very fast (e.g. below f/4) it might be possible to get a hint of it in less than 30 seconds.

I'm pretty sure I could see hints of M16 already emerging at a darkish site with a cooled CCD in 15 second exposures at f/5.

You could submit the shots you did get to http://nova.astrometry.net/ and check whether or not you were on target though. I can also solve images for you very quickly to see how far you were from the mark.

Anton

[JacobvonChorus]

With my modified camera in a completely dark location in my F/6.3 ED80, it only took a few seconds at ISO1600 for this nebula to show up. I could easily see it visually through my guide scope when setting that up. I may be wrong buy my guess is you weren't aligned on the target. You camera may not be modified buy you were using a much faster system than I was. As Anton said, try that astrometry solver, I haven't used it myself but it looks like a very powerful tool.

Good luck,

Jacob

[zakkhogan]

Thanks Ant, Unfortunately Nova couldnt recognize the image.

My scope is f\10, there is a f\6.3 focal reducer available, maybe i need to invest come payday

thanks

craig

[zakkhogan]

Thanks Jacob,

my gut feeling is that f\10 just isnt up to the task,

as i say i had been shooting all evening, and just tried to get a few shots to review for next time,

[badgers]

Hyperstar works great on the CPC but they are quite expensive if I remember.

On the other hand it will bring you waaaaay down to f/2 which would make a 15 second shot roughly equivalent to 5 minutes at f/10.

If you post the image you did get, I'll solve it for you. The nova server can have issues.

Anton