Tarantula Nebula

[winensky]

Finally, a clear night after two weeks with my new ccd sitting on the shelf.
By the time I worked out how to operate the software it was getting late so data time was limited.

I was reasonably happy with my first ever Ha shots but when I try to combine it the RGB image, it washes out and the cloud detail dissapears. I have, for the moment, left them as separate images but any advice would be greatfully accepted.

In any event its a big step up from the digicam.

Kind regards
Matt

Ha 15x1 min. unguided LXD75 8" SN DSI II
RGB 5x1min each. No flats or darks.

http://i213.photobucket.com/albums/c...avawasa/Ha.jpg

http://i213.photobucket.com/albums/c...vawasa/rgb.jpg

[NGCHunter]

Not bad for not having any dark frames, I would say once you apply dark frames you should be able to bring out the nebulosity a bit more by adjusting the levels. Other than adding more time into the integration there's not much I can say, but if you happen to know about what the temperature was when you took it, just plug the camera in somewhere at that temp and take some darks. Really good though, my old DSI 1 never used to produce a useable image without darks.

[winensky]

I finally worked out layering in photoshop so I have re-rendered the Ha at its natural frequency,combined the colour images and cleaned up a bit of noise. I think this is the most I will get from this data.

Kind regards
Matt

[galacticphoto]

There is a lot of good info in your image, but insufficient "stretch". Try a nonlinear stretch to bring out the nebular cloud w/o totally blowing out the central region.

The DDP in MaximDL is popular, also the various nonlinear stretches in the PS plug-in, FITSLiberator.

Robert

[kvwood]

Hi Matt,

Great first light image with your new camera! Congratulations. I agree with Robert, that you might be able to bring out a bit more nebulosity. Do you have photoshop? If so, go to Image/Adjustment/Curves. Grab the line about 1/3 from the bottom and begin to move it upward. You should begin to see the nebulosity growing with out clipping the white end. Make sure the line never touches the top. You can play with this until you get what you like, and even do it several times. (Do it for the RGB and the Lum seperately before combining)

Another thought you might consider is to combine about 30% of your Ha data into the Red data and about 10% with the blue data. Then once you have your RGB and Lum (Ha), layer the 2 with the the RGB as your base, copy the Ha on top and set the Ha layer as Luminance. This will get you started.

Also, be careful not to black clip the images. It is very easy to black clip and a alot of folks do without realizing it. I check this periodically in my processing, just to make sure, and I still end up clipping from time to time. This is what will help retain the star colors and help them look more true. I always leave the black point (Set in levels) pretty far to the left, which gives a gray background, until I am completely done with my processing sequence, then I set the black point in levels at the very end. You can tell if it is clipped by checking the histogram. Levels is found again under Image/Adjustment tabs

There are many ways to approach this. This is just one thought. You have a great image that you might be able to enhance even more with a bit more work.

Take care,
Kent

[winensky]

Thank you both so much for the advice and encouragement. I have tried streching the curves for all the colours individually in a set of Eta Carina from last night and I am reasonably happy with the result.

Kind regards
Matt

ps I have now done the same with this image and it has improved remarkably.
Thanks again.

Matt

http://i213.photobucket.com/albums/c...tprocessed.jpg

[JAICOA]

Matt you did a super job on Ccd imaging being your first. its a beautiful nebula looking forward to see more. Clear Skies