Ngc 253

[jsmoraes (Jorge)]

GSO 305 mm - Canon Rebel XT - 50 frames - 20 seg - iso 1600

After thunderstorm launched away the dome of my observatory like a WIFO (Well Identified Flying Object), two weeks ago.

With winds 10 ~ 15 km/h, brilliant Moon, top PL, inside a not totally recovered dome and no good mood. But it was done!

medium scale: http://i1063.photobucket.com/albums/..._ngc253_1k.jpg

large scale: http://i1063.photobucket.com/albums/..._ngc253_2k.jpg

I think that it would be better with not so sharp stars. It needs a repro.

[Larryp (Laurie)]

Very nice Jorge!

[omegacrux (David)]

Nice pics Jorge
Like your work

David

[jsmoraes (Jorge)]

Thanks, David and Laurie. Unhappily I didn't capture a good colors signal, and it seems black and white.

[TrevorW]

Looks like you have some dust motes and gradients in the image

[tilbrook@rbe.ne (Justin Tilbrook)]

Hi Jorge,

You are getting some good resolution, If you download a program called Iris, http://www.astrosurf.com/buil/us/iris/iris.htm. It has quite a good gradient removal feature.

Sorry to see your dome was damaged, hope you have it fixed soon.

Cheers,

Justin.

[jsmoraes (Jorge)]

Thanks, Trevor and specially Justin. I know that it can be better, but I am still trying IRIS.

Repro - with DSS - IRIS - Photoshop

GSO 305 mm - Canon Rebel XT - 50 frames - 20 seg - iso 1600

medium scale: http://i1063.photobucket.com/albums/..._ngc253_1k.jpg

large scale: http://i1063.photobucket.com/albums/..._ngc253_2k.jpg


And removing gradients and noise, only:

medium scale: http://i1063.photobucket.com/albums/...53repro_1k.jpg

large scale: http://i1063.photobucket.com/albums/...53repro_2k.jpg

[TrevorW]

Much better

[jsmoraes (Jorge)]

Every day is a day to learn, Trevor.

[Paul Haese]

Actually I think I prefer the very first image. Some noise is ok. You subs are a bit too short to capture enough colour signal. Am I right in reading that you are capturing 20 seconds for each sub? If so this image is good for so little exposure time. Might I suggest doing 5 minutes for each sub, that will give better signal strength and over whelm background noise. You will only need to use iso 800 at most too, which will also work better with regard to noise.

Flats are important too as Trevor has mentioned. Do some sky flats just after sunset. Dust motes can be most annoying.

Keep at it.

[jsmoraes (Jorge)]

Yes, Paul, they are 20 sec subs. I am installing my guiding set, now. But I will need some filter against lighting street. Perhaps I can shot with 1 or 2 minutes only.

I use flats, dark, dark flat and bias.

My Canon with iso 1600 generates much noise and its sensor had much dust at that time.

Thanks for your words and attention