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View Full Version here: : Comet Lemmon before and after processing


StephenM
24-02-2013, 01:28 PM
Hi all,

With all the clouds around, I decided to go back to the original RAW files and reprocess my image of Comet Lemmon passing the SMC and 47 Tuc on the 13th February. (This image was taken using just a tripod-mounted DSLR.) I'm much happier with this version.

In the process of doing this, I decided to put together a 3 panel image demonstrating the power of stacking images to improve signal to noise ratio and therefore image quality. I know that this is common knowledge to those who are experienced astrophotographers, but I thought there might be others with less experience who might want to capture an image of the current comets using just a DSLR and tripod. It still amazes me how much detail can be captured when you stack a few images!

Anyway, the first image shows the comparison of unprocessed RAW, processed RAW and stacked images of Comet Lemmon, and the second one is my reprocessed Lemmon/SMC/47 Tuc image.

Thanks for looking!

Cheers,
Stephen

Larryp
24-02-2013, 01:36 PM
The 2nd one is great, Stephen!

Domol
24-02-2013, 02:29 PM
Just wondering what ISO and len you used on the 50d?:thanx:

StephenM
24-02-2013, 03:13 PM
Thanks Laurie!



Sorry Domenic, I forgot to mention that in the first post! I used the Tamron 90mm macro lens at f/2.8, and 3200 iso. Because I was using the camera on a tripod (not a tracking mount), I limited the exposures to 20 secs. The final image was 20 x 20 sec exposures stacked.

Cheers,
Stephen

iceman
24-02-2013, 04:13 PM
Excellent!

bobbyf
24-02-2013, 05:12 PM
That's a great example Stephen. Well done. I'm waiting for less moon before trying for Lemmon and Panstarrs together hopefully and your info amongst others in the forum will help me a lot I'm sure.
Cheers
Bob

Phil Hart
24-02-2013, 07:52 PM
Great example Stephen. Well done on posting it. :thumbsup:

I'm finding this comet quite hard to process too.. a lot of compromises/decisions to be made compared to static deep sky objects.

Phil

StephenM
24-02-2013, 09:59 PM
Thanks Mike! Glad you like it.



Thanks Bob. I'm also looking forward to trying to capture the two comets together... if the Brisbane clouds clear in time. The next week's forecast isn't great though.




Thanks Phil! I'm no expert on image processing, but it looks like you did an excellent job on that Lemmon image you posted the other day!

Cheers,
Stephen

pixelsaurus
24-02-2013, 10:40 PM
:thumbsup:Triffic. Hope for me yet.

MortonH
24-02-2013, 10:50 PM
Thanks, Stephen. I am exactly the person this is aimed at since I haven't yet tried astrophotography with my DSLR, but used to dabble in the days of film. Just got a Polarie and this clearly demonstrates the value of taking multiple images. :thumbsup:

StephenM
26-02-2013, 10:40 AM
Thanks Mike and Morton. I'm glad it's useful.

Cheers,
Stephen