View Full Version here: : Destroyed Lagoon M8
EzyStyles
02-09-2007, 09:55 PM
:help::help:
Hi Guys,
On the road to image my best Lagoon, this came up. :eyepop::eyepop: I have no idea what or how suddenty blue pixels came about. I'm suspecting it might be dew fogging on the top between the filters (uv/ir & uhc-s ). I don't think this image can be fixed in anyway. maybe some sort of light source rejection? hmmm... question.. do i have to block the view finder when taking snaps?
If anyone can shed some light what causes these pixels. I have also imaged other objects within the same night. same thing in those images :shrug: .
cheerss
tornado33
02-09-2007, 10:20 PM
Gee, thats odd. Did these appear in every image you took that night? At first I thought they might be from dark subtraction that didnt work right but they are only on the top part. I take it they are on the original raw unprocessed images and did not just appear after dark subtraction and flatfielding? I would have thought if it was fogging thered be haloes round the stars.
Darn nice image too
Scott
Chase them with the colour range tool, then subtract the selection for the other regions (you'd need to do this as there will be other areas of the same pixel value that you don't want to modify). Then expand a few pixels and use a median filter. Alternatively go in with the healing brush. Once you've got one clean image, you can subtract the defects from the remaining images.
Looks like your sensor might be dying. Usually the mirror flips up blocking the light from the viewfinder coming in. Try some more pictures see what happens.
Great picture though :thumbsup::lol:
Eric, it is a good idea to block the viewfinder while taken long exposures, the Canon range of cameras supply a cap exactly for that reason of stray light.
I don't know where you live and if the light pollution has changed, but it seems that this has just happened since you relocated.
Please correct me if i'm wrong.
Leon
Garyh
03-09-2007, 08:21 AM
Thats a beaut M8 Eric!, pitty about all that noise from the hot pixels!
Could you be able to post a DF from that night? also details of exposure etc and temperature?
I know I get a few blue hot pixels but mainly down in the lower left corner where there is more amp glow..
cheers Gary
Dr Nick
03-09-2007, 04:36 PM
If you ask me, thats a beautiful picture! ;)
EzyStyles
03-09-2007, 08:43 PM
just found out the culprit. It is indeed my darks!. I have no idea why there is a black circle right in the middle. also looked at individual m8 shot, not evident only in the dark frames. when used with my old darks, it seems fine. Will finish processing the final pic and post it up. Thanks for your suggestions and help guys.
Garyh
04-09-2007, 07:31 AM
See what you mean with that dark! Eric..look forwards to your best M8 when redone!
cheer
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