Tarantula 400d ED80

Astrod00d · #1 06-04-2008, 05:53 PM

Hi All,

Yes, another image of the Tarantula.

This is a stack of 53 frames over 3 nights, varying in time from 30s to 240s. Levels and curves in Photoshop5. I've tried to push the levels to show the extensive dust clouds and part of the starfield associated with the LMC, without over-exposing the centre.

I feel there should be more red in this image, it seems way too blue-green. Is this because the 400d is not seeing the Ha part of the spectrum? Do I need a modded DSLR?

Have I hit the limit for an ED80 and an unmodded DSLR, or am I missing something??

ED80, 400d, 800iso, 53 frames, 30s to 240s, darks, Deep Sky Stacker, levels and curves Photoshop5.

Cheers,

Rob

dugnsuz (Doug) · #2 07-04-2008, 11:49 AM

Quote:

Originally Posted by Astrod00d

I feel there should be more red in this image, it seems way too blue-green. Is this because the 400d is not seeing the Ha part of the spectrum? Do I need a modded DSLR?

Have I hit the limit for an ED80 and an unmodded DSLR, or am I missing something??

Nice image Rob - lots of data collected there.
I had a similar problem with the Tarantula and the colour red!!!
I also have a similar setup - ED80/40D.
I found pushing the exposure time to 10min subs (and fine tuning through processing) helped bring out those faint reds and browns seen in other pics.
Here's my best attempt...
http://s231.photobucket.com/albums/e...ebula-High.jpg

All the best
Doug

leon · #3 07-04-2008, 12:03 PM

Good one Rob, and although the colour is not quite right, you have managed to get some good detail in that shot.

If it is a Modded DSLR you want than check out the For Sale section, just what you would need to get that HA out.

Leon

Astrod00d · #4 07-04-2008, 12:07 PM

Thanks Doug, you've certainly got good colour and detail there.
I'll try longer subs next time. What ISO did you use for the 10-minute subs? I did all mine at 800 ISO, but perhaps the 400d begins to get a bit noisy at 800ISO. Maybe I should stay at 400.

Cheers,

Rob

dugnsuz (Doug) · #5 07-04-2008, 12:14 PM

Quote:

Originally Posted by Astrod00d

Thanks Doug, you've certainly got good colour and detail there.
I'll try longer subs next time. What ISO did you use for the 10-minute subs? I did all mine at 800 ISO, but perhaps the 400d begins to get a bit noisy at 800ISO. Maybe I should stay at 400.

Cheers,

Rob

iso 800 for my Tarantula pic I think Rob.
Doug

leon · #6 07-04-2008, 01:25 PM

Rob I'm no expert, far from it, but with experimenting of ISO settings I have found that 400 is your best option all round, that is all i shoot now.

You get reasonable dynamic range, and the noise factor is also reduced.

It may be that you have to expose a bit longer, but you will see the difference, well that is my 2 cents worth.

Leon

Astrod00d · #7 07-04-2008, 03:25 PM

Hi Leon,
Yes, I've read somewhere that 400iso is best for the 10MP Canon cameras, I used 800iso to reduce my exposure times, and hoped that stacking would reduce the noise. I may not have given enough consideration to dynamic range. Next clear night, I want to try 10min to 16min subs at both 400 and 800iso, and compare the results.

Cheers,

Rob