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Change in Histogram when saving as JPEG?


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Is it normal for the histogram to change when saving a PSD file as a JPEG?  I have a situation where my PSD file shows one tiny catchlight in an eye that is at 255 on the histogram.  The rest of the image is well within range.  I pull up the JPEG that I saved, and there is now a larger catchlight in BOTH eyes, plus a patch of teeth, and a few small patches of skin on the edge of an ear at 255 on the histogram.  The photo the LAB received from me, they are telling me that patches of the people's faces, AND one whole white shirt are completely blown out as well.  What could be causing this?  Thanks!

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OK, yes, i used Levels to check for clipping, and that's where I was seeing it on the JPEG, but only on the catchlight in the woman's eye in the PSD (and on the metal clamp on the left, but that's obviously cropped out later).

Attaching screenshots.  This was for a piece of photo jewelry.  It was apparently printed on pearl paper, which I did not know going in.  I do not have a copy of the file the guy at the lab was looking at, but he said the boy's shirt was completely blown out on that copy, and it is not on mine.

screenshot jpeg.jpg

screenshot psd.jpg

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I also just did soft-proofing with the color profiles from the lab, and there is negligible change, mainly in the mom's neck area, which was not a problem in the finished jewelry.

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Well, on the PSD file, as I was working on each levels layer to adjust contrast, I tried to never touch the ends of the histogram completely.  And for the most part, the PSD files are fine.  When I open up the jpeg, I added a blank levels layer on the top, and clicked "ALT" and the right histogram slider thing.  I'm seeing some clipping, though minor, on the JPEG--definitely more than the PSD, though.  The guy at the lab said he was using the levels layer method as well and saw clipping all over.  The file was uploaded via ROES.

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Sorry.  It was a long day yesterday.  I  checked both the PSD and the JPEG using the Level layer method, and there was significantly more clipping on the PSD.  Where there was only one point of clipping on the PSD (a catchlight), the JPEG had clipping in two catchlights, the woman's teeth, and along the boy's right ear.  Then, the employee at the lab said he was also seeing clipping, using the same Levels method, on faces and the boy's shirt.

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OK, I've done an experiment.  I've gone back to the file, and edited so there is no clipping.  I saved as a JPEG, no clipping.  Then, I applied sharpening: clipping EVERYWHERE.  So, the sharpening is introducing the clipping.  Does this mean my file was too close to the edges of the histogram to begin with?  Is there any way to predict how much the sharpening will lead to clipping?  I've never noticed this happening before, but I've always assumed if my file was clipping-free when I was done editing it, that it was good to go.  Clearly, I was wrong. :(

 

P.S. I have taken the print sharpening class and am following those instructions to complete the sharpening.

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I have now completely re-edited my file.  I reduced exposure in RAW, even though it didn't need it based on the histogram.  I have reduced midtones and did NOT push highlights during my levels editing.  I had NO clipped areas when I had completed the edit.  I cropped the file at 300ppi, and did NOT save as a JPEG yet.  Did NOT sharpen yet.  Clipping all over.  What on earth is happening?

Is it because the file size is so small, being that it's for jewelry? 

Edited by SarahS76
added qustion
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2 hours ago, SarahS76 said:

I have now completely re-edited my file.  I reduced exposure in RAW, even though it didn't need it based on the histogram.  I have reduced midtones and did NOT push highlights during my levels editing.  I had NO clipped areas when I had completed the edit.  I cropped the file at 300ppi, and did NOT save as a JPEG yet.  Did NOT sharpen yet.  Clipping all over.  What on earth is happening?

May I see screenshots for this?

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I've circled the only clipping on the PSD, and it's on something that is cropped out of the final.  The final image is cropped to 1x1" at 300ppi to fit on the necklace.  Hopefully you can see where the clipping is appearing on the skin now....Let me know if you wanted the images instead of the clipping.  I wasn't exactly sure what you wanted to see.

JPEG screenshot.jpg

psd screenshot.jpg

Edited by SarahS76
spelling mistake
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