Viewing changes that have been made to a photo?

[Photo__Dude]

I was wondering if it is possible to take any photo and view the changes that have been made to it in photoshop. For example, can I open a .dng file from 3 years ago and view the changes I made to it during post processing?

My software:
CS5
Lightroom

My file types:
From RAW to PSD to DNG

 

[KmH]

Yes and no.

If you edit the Raw in ACR, then edit as a PSD in Photoshop, then convert the PSD to DNG, no, the DNG file will not have the edits.

If you edit the Raw and then save to DNG, yes, the edits made in ACR are written as XML command lines in the DNG file.

Using Camera Raw you can open the Camera Raw flyout menu.
The 'Image Settngs' selection will show the state of the setings the last time the image was opened in Camera Raw.

When I do edits in Photoshop as PSD file, I use layers for the edits, and save the layered PSD file if i want to go back later and see which edits I made.

 

[ann]

You can also go Edit>Preferences > General > check the box next to History Log > click on Metadata >click on detail , apply

then when you work on a photo and want to see what you have done. Go to File info. find the tab that says "history" and it will give you a list of what you have done, etc.

Can be very helpful, as I used to write things down so I could learn what I was doing and be able to repeat with some degree of intelligence.