out of the blue, when i go to Save As my tiff, the options are about halved. and jpeg is not one of them! suddenly i cant turn a tiff into a jpeg. help!
Markerline's advice is right on for versions of Photoshop before CS5. In Photoshop CS5 and newer, if you're working on a 16 bits/channel image it will actually offer the JPEG setting, saving you several steps.
Interesting Noel. I wasn't aware of that update to PS. Just out of curiosity and I may be entirely wrong,... isn't there a situation with web pages where anything besides an 8-bit image isn't supported. For instance 8-bit PNG vs 24-bit PNG? That may have changed with HTML5 anyway but I thought in my studies I remember having issues with 24-bit PNG and thus a 16-bit JPG might also cause concern. Am I on track about this issue?
It just automatically switches to 8 bit and "as a copy" operation to save JPEGs from 16 bit documents. There's no problem with the saved files.
I don't know how many other formats this shortcut applies to. I know I (probably among others) requested it going WAYYY back, because without it what I was occasionally doing (by accident) was switching my document to 8 bits/channel, Save As JPEG, then forgetting to go back in the history to preserve the 16 bitness in the master document.
From what I have seen, all the modern browsers handle 24 bit PNG files nowadays, and have for some time.
"24 bit PNG" is a mis-nomer (confusing bit depth with total number of bits)
It's 8 bit/channel RGB.
And yes, some web browsers don't support 16 bit/channel PNG (though most do now).
JPEG isn't an issue, because it is almost always 8 bits/channel. When you save a 16 bit/channel image in Photoshop, it gets converted to 8 bits/channel for PNG.
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