M81 - "Bodes Nebula"

Dave,
Super images.
Personally though, I would like to have the levels reduced so as to remove the noise somewhat. Here's my attempt at re-processing the first image.



What do you think? Have I removed too much detail?

Thanks for that Micheal. I totally agree with you that noise is the biggest factor here. I dont think your levels adjustment hurts the detail too much. I will say that reducing the size of the image does make it appear less noisy. However personally I like to see scale!!

Tell you tthe truth I was a bit dissapointed when I saw my first version of the image.Its kinda grown on me since the reprocess. Anyway the inevitable post mortem between myself and Jed came up with a few points which we agree on.

1: Many more frames are needed. This was a combo of 6 x 10min and 8x 5 min. 25 or so 5 mins would probably have produced a much better image.

2: this was done through my f/12 mak. f/12 is too long for this sort of image. The c9.25 @ f6.3 would probably have been a better choice.

3: The light pollution filter seriously hurts galaxy portrait shots. Though it may be impossible to do without it it does reduce the dynamic range of colours a lot.

4: I used to think that if you took darks the next night, as long as the camera was at the same temperature then it would be ok. We came to the conclusion that darks must be taken on the same night. Otherwise variations occur depending on stuff like, how long the camera has been switched on etc.

Ah yes, the quest for better images, a game with no end!!

Ah yes, the quest for better images, a game with no end!!

Yea! Tell me about it!

Wow, that's an amazing image. I was looking at the same area and the galaxies in Virgo last night but saw nothing nearly as clear as that. Last night it was still pretty high after midnight.

Had the moon gone down at that stage?

Trev

Trevor,
Even with a big scope, it can be very difficult to see those spiral arms in M81, the photogrpah really exagerates there brightness.

Lovely image, but we need more data

Later,

Jed.