Post-processing of images

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Post-processing of images

Postby nozzmoking » Mon Dec 12, 2005 1:50 pm

I really enjoy looking at people's imaging efforts, and we've already got some great pics posted in the photo gallery.

I've come across many pics on other sites where the full technical spec. has been given to how the image was achieved, e.g. how long the exposure, how many frames stacked etc. and quite often I see that the image was further processed in Photoshop, or a similar program.

What kind of processing is done in Photoshop? Is it mainly colour balance, colour removal, sharpening etc?

How do you know what actually needs doing to the image to improve it? Is it obvious once you see it?

Are most images satisfactory on the first attempt (in good seeing conditions) or is post-processing the norm for the majority of images?

Apologies if the above questions sound a bit dumb, but I'm preparing my self for the road ahead!


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RE: Post-processing of images

Postby Chanctonbury » Mon Dec 12, 2005 3:46 pm


I use an old version of Photoshop ( V 4 ) but it does everything that I need it to do for the base post processing of my images. I mainly use it to darken the background sky to inky black using the 'black pipette' and then I adjust the individual R, G and B 'levels' to bring out the foreground detail that I want. I then use 'canvas rotate' (if necessary) followed by 'crop' to get the best composition from what I have taken and then I normally re-size the image to 600 x 400 for inclusion on my web site so that the pictures will download reasonably quickly and yet be large enough to identify the object in question.

I never use 'sharpen' as this is likely to bring up background 'noise' which is undesirable. Very occasionally, I use 'contrast' or 'colour balance' but prefer not to as this can give an artificial look to the image.

I use a digital SLR camera (Canon EOS 300d) and because of light pollution and image 'noise' on long exposures (3 minutes or over) I very rarely have an image that is correct without some post processing. I normally take 5 to 10 2 or 3 minute exposures plus a dark frame exposure which I then stack using Registax to get more detail and lose most of the unwanted signal noise leaving me with the light pollution to deal with!
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