I’m not even sure how to ask this question because I really don’t know what is going on or if it even matters. I have an image whose RAW dimensions as listed in the metadata of Lightroom are 6240x4160. So, then I exported the image into Photoshop and did most of my editing (no cropping) there and sent it back to Lightroom as a tiff file. But now, for some reason unknown to me, the dimensions are 2100x1500 (according to the metadata) - same ratio but different size. When I look at the original RAW at full size (“Fit” in Lr Navigator) and compare it to the tiff at full size, they look the same size on my screen but if I move the size slider and make it smaller the tiff file appears to shrink down much, much smaller than the RAW with the same slider settings. Can anyone tell me what’s going on or if it matters?
Hi Kerry. I think it does matter. Somehow your image was downsized when you saved it from PS back to LR. I would suspect that you accidentally clicked on something that changed your default saving system. There used to be a “save for web” in PS, but it hasn’t been there for awhile so as long as you’re running the current version that can’t be the culprit. If you want that image for more than posting on the web, I’m afraid you may have to reprocess it. Before you do so, I’d suggest you just pick a random file, send it from LR to PS then save it back to LR and see if the problem repeats.
There are plenty of others on the site that know a lot more about how this stuff works than I do, so hopefully they’ll chime in.
Thanks @Dennis_Plank I would sure like to know what I did so I don’t do it again. Plus, I put a lot work into it so I’d like to find out if it is possible to go through my work flow and see if I can’t correct the problem.
P.S. I did do a test with a random file and it was fine.
I think I spotted the problem. I did something I almost never do, namely crop in Ps.
And the problem, I think, is that when I cropped I did it by size instead of ratio, so, actually I inadvertently downsized the image. There is no way to repair that since cropping in Ps is destructive. But I’m sure the re-do will be better 
Ouch! But I’m happy to hear you found the issue.
For future, the Ps crop has option to delete (or not to delete) the cropped pixels. So you might want to change that to not to delete, if you have that on delete now.
Thanks for that. Very helpful.