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pjmaciw

Orion nebula - first proper attempt

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Up until now all my photo's were snaps to see if this or that worked and to set up my equipment.

On Sunday it was a clear night so I thought I would have a proper attempt at taking some subs, stacking and processing. This is the result of 50 x 30 sec subs, stacked and processed. I have real trouble with the processing but now feel that I am getting there.

I did not take any bias, dark or flat frames and am not quite sure how they would change the final image. The thought of taking dark frames is not very appealing. Are bias, darks and flats needed with DSLR's considering the high pixel count. I think you would be hard pressed to find a hot pixel out of 18million pixels.

Orion_Nebula_3-1.jpg

Orion_Nebula_3-1.jpg

post-23324-133877700563_thumb.jpg

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Hi

If you shot Raw files with your 550D and use Photoshop to convert them to 16bit tiffs it seems to automatically take out all the hot pixels. I'm shooting with a modded 550D and hardly ever bother to shoot darks, here's a link to my latest image, 48 frames 140 sec each no bias, darks or flats.

http://stargazerslounge.com/imaging-widefield-special-events-comets/165617-asteroid-15-eunomia-crossing-california-nebula.html

Mel

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Very nice animation Mel. I suppose having a modded cam helps with the red. That's another thing that I wonder about. With an unmodded dslr can I still get similar pics to a modded dslr if I increase the exposure or is the info completely filtered out in an unmodded dslr.

Back on subject - It occurs to me that only the flats may be useful and I can propably not worry about bias and dark frames, for now at least. I think I shall try to get some flats next time and see if I can see what difference they make.

Pete.

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Hi

If you shot Raw files with your 550D and use Photoshop to convert them to 16bit tiffs it seems to automatically take out all the hot pixels.

Incorrect, unfortunally.

It attempts to take them away, but it's not able to take away nerly all the hot pixels if you have many bright ones of them. I have that problem with my 550d, and DPP doesn't remove them (some are removed, some are just slightly dimmed, some are left almost untouched). However, with PS lightroom, they wanish completly as soon as it have loaded the raw file.

Though, DSS also removes them completly from what i've been able to see, so i've never had to bother with converting them all before stacking them. Even without darks.

Edited by Jannis

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Darks flats and Bias offset shots are a pain but they do improve your images. I let my timer take care of them while I bug off for a coffee set it to take 30 darks then come out and stick a sheet over the scope and plonk an led light in front of it and let the time do another 30 then lastly wap off 30 bias offsets with the shutter speed as fast as it can go and jobs a good un.

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Darks flats and Bias offset shots are a pain but they do improve your images. I let my timer take care of them while I bug off for a coffee set it to take 30 darks then come out and stick a sheet over the scope and plonk an led light in front of it and let the time do another 30 then lastly wap off 30 bias offsets with the shutter speed as fast as it can go and jobs a good un.

Good idea think I will try that next time...that is an amazing photo of the orion gonna be ahwile before I can grab a proper imager, but that would be just a blast to get seomthing that beautiful...well done.

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