need help with adobe photoshop!

CCD vs Film? Lots of time vs no patience? Alright, this is your place to discuss all the astrophotography what's and what's not. You can discuss about techniques, accessories, cameras, whatever....just make sure you also post some nice photos here too!
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MooEy
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Joined: Sat Oct 04, 2003 6:24 am

Post by MooEy »

hmm.. off topic by now, some mod pls split this up and move it to a proper thread.

ok, alot of misconceptions here. alot depends on what u are photographing. for planets, exposure is usually short, something like 1/15 sec to 1/4 sec. tracking is not that important. for deep sky objects, on a iso 400 film and a f/8 scope, u will prolly need 30min-1hr expsoures.

most people shorten this time on digicam by working with higher iso and faster scopes. shooting raw helps even more. if i use iso 800, a f5.6 scope, i would have shorten my exposure by 2 stops, which is only 8min. by shooting in raw, i can push it even further by maybe 1-2 stops, that bring it down to maybe 5-10min on iso 400. post processing and stacking will bring it to an acceptable level.

for planets, we usually stack like mad, at least 200 frames will be needed. i seen charlie stacking 1416 frames for mars. stacking will increase the amount of details we see.

for expsoure above 1min, tracking is crucial. perfect polar alignment is a must, no amount of guiding can ever cure inproper alignment, as the image on the film will prolly suffer from rotation and motion blur. star will prolly look like "Z"

~MooEy~
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Airconvent
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Post by Airconvent »

both sagi and scorp are very clearly seen in the original pic.
in the re-processed image, they are no longer obvious although M8 seems to want to pop out now.
as a purist, I guess the first pic is better and it depicts the constellations clearly. the processed image should be academically used for bringing out some details but at the expense of quality...
but good effort mooey...looks like you can be singastro's resident image processor! :lol:

rich
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