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leon
21-03-2009, 09:39 PM
Hi Guys as some of you may have seen my posted image of the Sea Gull Nebula yesterday, I mentioned that i would attempt to add some more Data and give it a bit of a boost.

Well last night I was able to capture another 12 sub frames and have added them to the 6 I took the night before.

I intend to do another night on this object, but it is actually clouded out tonight, so I will just post this image which is of the two nights combined, totaling 18 sub frames, at 400 ISO

All were taken through the Tak and Modded 5D, on the G11, and Auto Guided through the WO, 80mm FD, using a Orion Star Shoot Camera, ICNR was on, and Flats applied.

The first is 18 sub frames and the second is only of the 6 I took the night before

Please comment and thanks for looking.

Leon :thumbsup:

strongmanmike
21-03-2009, 10:10 PM
Well Leon to be honest it's hard to tell any difference at that image size other than the longer exposure is more magenta. Perhaps you processed the two night image differently? Have you noticed a reduction in noise?

Mike

leon
21-03-2009, 10:25 PM
Mike I,m inclined to agree with you, it is difficult to see a lot of difference, however I did notice considerable noise reduction between the first 6 I did, and the combined lot of 18 frames.

I did try and process both batches the same, but have noticed a definite colour change between both images as well.

Leon

Craig_L
21-03-2009, 11:41 PM
Hi Leon,

I've had a couple of goes at this subject with the Tak and a 450D and I personally think you have to go harder with 800 ISO and 10min subs to get enough photons. You'll get more noise but makes the subject much more appealing. My opinion anyway.

gregbradley
22-03-2009, 12:32 AM
Nice image Leon. You may find you can push the longer exposure image harder to bring it up. Lower noise and the ability to be pushed harder is what you get from longer exposure time.

Also ISO400 may not be sensitive enough. ISO800 or 1600 may be the go.

Greg,

Paul Haese
22-03-2009, 11:02 AM
Nice image Leon. I also agree with longer subs and more ISO. The signal increase is so much great doing this that it more than compensates for anything else. You can do your darks later if you like. I have found that I can use darks from longer sub sets but just need to use a bias set to compensate in the subtractions. Meaning that you can use darks that are several minutes longer and still apply them to a shorter exposure image.

Many of the top DSLR guys also suggest that you can also use a wide ranging dark set where the temperature ranges drastically. You don't really need to do the darks at the same time. I have found that this is also true. You can then make a master dark that covers a wide temperature range and with differing durations.

You might like to try perhaps increasing the contrast a little, just to reduce the flat look the image has. Just my opinion of course and I leave that up to you.

leon
22-03-2009, 12:04 PM
Thanks Guys, I have to admit you are not the only ones that have told me to push it a bit harder, :whistle: so I will give it a go. :thumbsup:

Ya, know what though, it took me long enough to get to 8 minutes subs, :whistle: and now you want me to go to 10. :P :lol:



Leon :thumbsup:

desler
22-03-2009, 12:25 PM
There's no way I could comment on the technical aspects of the captures or the processing. I just love looking at fantastic images. Well done Leon.

Darren

Garyh
22-03-2009, 12:54 PM
Good to see you had some more photon capture time Leon!
Now hit it with some curves! and get that fainter stuff showing!
Look forwards to what you shall achieve :thumbsup:

leon
22-03-2009, 03:34 PM
Glad you like it Darren, :thumbsup: I don't reckon it is half bad either, especially, from a novice imager like myself, thank you.

Gary, I just wish I was more efficient with the processing part of this hobby, sometimes I just don't quite know how to go about it, :shrug: and I know there is probably more to extract from the Data.

Leon :thumbsup: