Sharpening and noise reduction can only be viewed accurately at 1:1 view, and should always be applied at 1:1 view.
Any other view will be inaccurate and misleading.
Library and Develop use different resizing algorithms. so they will only match at 1:1.
Exported files also need to be viewed at 1:1 to evaluate sharpening and noise reduction.
Again, different viewing apps use different algorithms to resize an image that doesn't fit in window at 1:1 view.
Thank you Per Berntsen. I am aware of the 1:1 view needed to for the sharpening/NR but unless I switch between Library/Develop modules, I can't tell how the photos is going to actually look like. At 1:1 the photos match, but the Exported photos are nowhere near as sharp as the ones viewed in Develop module. Anyway, thanks for your reply.
How are you exporting? If jpg, what is Quality set to?
Full size, or resized?
A full size jpg at 100 quality should be very similar to the original, with no output sharpening.
But if you resize, the image will become softer, and you may need to use output sharpening to keep it sharp.
I am exporting the photos as jpg (from RAWs) at 100 quality and without re-sizing. Also,the changes I do with the adjustment brush for sharpening, seem to disappear the moment the photos are exported. It's just annoying that the photos look nice and clear in Develop module but in Library or when exported, they are so different. I will just have try to take better pictures in first place!
Sharpening should carry over to the exported file.
Can you post screenshots at 1:1 of the original file in LR and the exported file, that shows the problem?