if you load the photo in and edit it, the photo will not get destroyed, as long as you don't save it as the same jpg name
of course if you are using raw then its all changeable anyway
Make one of the adjustment layers, adjust the brightness, then either delete the adjustment layer or turn it off. I do that all the time.
Menu->Proof Setup->Custom->Device to sumulate: *wscRGB + Preserve RGB number set to On -> OK
Then press Ctrl+Y to toggle.
Awesome--some of my menu choices were not the same so I had to guess but I did it and it preserved the original brightness.
View->Proof Setup->Custom->Device to simulate: sRGB ice (bunch of nos.)->Preserve no. set on
And Voila! it returned me to my orignal colors and brightness and maintained the other changes I made.
I am not very well versed in layers. I made an adjust. layer, increased brightness, but was not able to edit anything. I need to practice more on these. Thanks.