Let me start by saying that I've uninstalled and re-installed PS and LR recently. Both are most up to date CC versions. Both are using ProPhoto RGB. Images look fine in LR and PS but "Save for web" JPEGS and LR exports both appear darker. Camera profiles aren't the culprit. I've recalibrated my NEC monitor with both Spyder 3 and DisplayCal. I've tried using the sRGB profile. Nothing seems to work. JPEGS appear the same as if they are proofed with "Monitor RGB". I'm at a loss as to what to do...
It's most apparent in the blacks. This is a lightroom export but PS JPEGs look exactly the same.
Adobe figured this out for me. It's IrfanView. IrfanView is not color managed. Opening the same file in windows picture viewer shows no difference. Damn non color managed apps!