Make sure you do not have the Soft Proofing option checked in the Develop module, this can cause perceptual changes to the image.
why does an image look different when I go from Develop to Library or back and forth. The histogram does not appear to change but you can see a difference and I have printed them and see the difference. Very strange and I'm not sure how to process the image
What version of LR and OS are you using? Please describe in detail exactly what "differences" you are seeing (darker, hue shift, less sharp, noise, etc.).
Things to Try:
1) If using LR 6 or CC 2015 uncheck 'Use Graphics Processor' in LR Preferences and then restart LR:
2) Recalibrate your monitor if using a a Spyder or i1 Display calibration device. If not using a calibrator reset the monitor profile as outlined here:
Not sure if this is where I reply. Reached an Adobe person and they said
it's because Develop uses proPhoto and Library uses sRGB and users go
between D & L til they get the image they want. Sounds like a lot of work.
Will try your suggestions. Thanks
Most image files will not look "different" due the narrower Adobe RGB color space used by the Library preview files versus Develop module's ProPhoto RGB working space. What monitor model are you using? Are you actually seeing color hue differences or something else?
We could help further if you provide the requested information:
"What version of LR and OS are you using? Please describe in detail exactly what "differences" you are seeing (darker, hue shift, less sharp, noise, etc.)."
It's all in the details...even when talking to us non-Adobe people.
I just did an update in the Help and all seems OK i.e. no difference
detected between Develop and Library.
> Adobe person and they said it's because Develop uses proPhoto and Library uses sRGB and users go between D & L til they get the image they want.
Yeah that is misinformed. Only on a few very high quality monitors should you be able to see any difference and even then it will only show up in some images and be quite subtle. If you see differences between Library and Develop it is almost always a bad monitor profile which is fixed by recalibrating the monitor using calibration hardware (essential equipment when you do photography on any computer) or it is the already mentioned problem with the gpu acceleration not loading the right monitor profile. That's fixed by turning off the GPU acceleration in LR 6/CC.