Matt. K wrote:My understanding is that you can open and close a JPG until the cows come home and it will not re-compress unless you have made changes to the image.
Just opening and closing the file would pose no problems.
As soon as you
save the file - changed or not -
if the application the saves the data (not all apps will) you would be reinvoking the compression routines and thus degrading the images.
Taking that a step further (and working from memory)
PS disables the "save" option (and thus prevents you from saving the file) unless and until you've made a change in that file. By way of contrast, Irfanview permits you to save a file at will, and rewrites the file every time, thus causing degradation each and every time that you save it.
Now ... as a very simple example, what about one image, shot in jpg in portrait
mode? In order to prepare that image for presentation you might - at the very least - need to rotate that image through 90 degrees. There's your first save, and your first recompression.
If exposure, composition, wb, etc are all exactly what you want, then great; you're done. But let's say we just want to crop it a little .... get rid of some annoyance from the edge ... There's a second recompression.
Of course, you could restart the process with the original jpg, and execute both of these changes in the one pass before saving, but I think that from a workflow perspective, that could become tedious.
Especially if you then decide to nudge the wb a notch or three.
So, it's not quite as simple as just opening and closing a file, and it bears dependancies upon the editing/viewing client that you're using, and what you're actually trying to achive.
My preference (workflow),
btw, is to shoot raw + basic jpg, and copy them all to the HDD. I then segregate the jpgs from the nefs, and use Nikon View to browse the nefs. If I see one I like, I'll open it in Nikon Editor (not Nikon Capture) and, if it needs adjustments, try to use the (limited) adjustments NE gives me. 9 times out of 10, they're more than adequate.
I'll then resize, and save the resulting image as jpg in another folder containing just these processed images.
That's exactly the process I followed for the images I posted this week, using the 24-120 VR. It seems to be reasonably quick, and quite reliable for me, and I always still have my untouched nef image should I decide to do something different with it at a later stage.