On my initial foray into Photoshop about a year ago I don't think I ever got clear on the sizing issue. To be safe I always cropped the image to 20x24 immediately then began to retouch it.
I usually print 20x24, 24x36, and they come into photoshop from the card at about 57 meg. The part the escapes me or never really got settled is, at what size does one start to manipulate and deal with retouching of the image.
What I've been doing is sizing the image to say 20x24 or the largest I will print it and then start to work on it. When I'm done, this is what I call my "master". It is often over a gigabite file. Then if I want an 8x10 say, I'll down size it to that, then print it. Same with say 16x20. I often keep all these size files in a folder which is pretty large. I keep them all because when printing, the adjustments are usually the same except for the exposure.
My questions is:
Is it the same thing to, when bringing the file into photoshop just leave it at the 57 meg and do all the adjusting and retouching at that size then call that the "master" (which will obviously be a lot smaller file than what I've been doing,) and then upsize to the 20x24 etc when deciding the sizes I want to print, or should I upsize immediately when bringing the file into photoshop.
The disconnect in my mind seems to be that: is it better to work on large files of an image or not. Will the image have the same quality if retouched at 8x10 and upsized to 16x20 as it will be to be retouched at 16x20 and saved at that.
Thanks in advance.