M8 Widefield

[AstroJason (Jason)]

Hey all,

Finally managed to get my NEQ6 mount to not lose its data connection to my laptop. This meant that I was able to use Alignmaster to get pretty good polar alignment. So last night I managed to capture the attached image using my 60D and 200mm lens. Why is it always a full moon when I manage to get some time to do some imaging? Also the Souths V Dragons game was on while I was imaging so that added to the challenge of getting this data.

I must say I am getting pretty happy with my processing techniques to pull all this data out considering all the light pollution I am battling. Basically, any exposure over 1 minute at just ISO200 means I get a bright white frame...

So here are 120 x 30 second exposures at ISO200. Darks and Bias applied, no flats, as I was finding with these images out of my DSLR there was no difference with or without them to the final result.

Full uncropped frame and a close up on the Trifid and Lagoon. Any feedback greatly appreciated.

Thanks for looking.

Jase

[blink138 (Pat)]

nice jason......... what was the lens stopped down to for that?
pat

[AstroJason (Jason)]

Thanks Pat. Actually it was shot wide open at f4. Would stopping down help sharpen the stars?

[nebulosity. (Jo)]

G'day Jason
I like your pic! Very nice considering the conditions I can get 128 second exposures at iso 500 f2.8 with no sign of LP

[AstroJason (Jason)]

Damn, lucky you! What I would do to be under dark skies more often.

[rcheshire (Rowland)]

Hi Jason. Very nice. As you requested feedback and I use a 200mm lens for virtually all my imaging, I hope the following is helpful.

Stopping down will give a flatter field and rounder stars to the corners. It will also improve the resolution of the lens, depending on make and model. You might need to bump up the iso to 400 in that case. I agree with lower iso generally in light polluted areas. Integration is slower and star colour is better. More dynamic range. Your image would benefit from another hour or so of data

Perhaps vignetting is not so obvious and flats make little difference, but flats reduce other artifacts as well - I would use them anyway.

[tlgerdes (Trevor)]

Something else to help with LP, add a light shroud around the lens opening that extends about 10cms in front of the lens. I stuck some black felt to a plastic laminating sheet and wrapped it around the lens with some tape. This will help and probably get you 60-90 sec exposures.

[killswitch (Edison)]

wow looks heaps good jason, considering where you live.

[AstroJason (Jason)]

Thanks for the tips Rowland and Trevor. I will give stopping the lens down a try next time I get a clear night. Will also try to get more data next time than just an hours worth.

Cheers Ed, yeah Im surprised I could get this much detail out and on a full moon night. A full moon should be no excuse for improving my imaging techniques now.