Highlight/Shadow blowout

[wideangle]

Why is it that when you have an original full size image up on screen and check levels for highlights/shadows they are fine, but then when you say shrink for web and check there are blown highlights and shadow areas? In saying that they are blown, its not massive, but it is more there.

I take it that the historgram is just representing pixels that are bunched closer toghther so the 'looser' pixel information is lost?

[pgbphotographytas]

I can't say I have ever noticed this myself but what your saying does sort of make sense to me.

Paul

[ricktas]

JPG compresses the range of colours.shades etc in photos, so it could make sense that if you are very close to ultimate black or white, that the JPG compression algorithm moves those slightly and you end up seeing the results you have.

Good information on how JPG compression works is here

[Nicholas N]

Never experienced this issue myself after loads of resizing and conversions.

All I can assume is that your shooting in Adobe and then converting to sRGB.