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<p>I can't remember where I read this, but I had thought that photoshop wouldn't do many functions at higher than 8 bit.</p>
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<p>A little over a decade ago, that would have been true. The move to 16bpc support started ages ago and is basically done with today. We're now at the point now where <em>most</em> functions will even work in 32bpc. That this kind of information never dies is a liability of the information age.</p>
<p>Unless you're rocking an extremely old version of Photoshop (or a woefully underpowered computer—the extra overhead does demand a bit of added grunt), 16 bit is perfectly fine. It's the golden age and the water's fine. Come on in! ;)</p>
<p>Like Mssrs. Harrington and Ferrel, I don't see anything out of the ordinary in your crop.</p>
<p>To throw another possibility out there, it could be a bad monitor profile, assuming you've profiled your monitor.</p>