Reader Comments: Eliminating a Channel in Lab Mode in Photoshop
Brian K writes:
I don't know if you've been shooting IR recently (my suspicion is no). The IR section on your site references an old version of PS. I've done channel swapping in PS before and the current version of PS seems to work with that method.
I hadn't done color inverting before with images in Lab. The current version of PS seems to make this harder than your IR section suggests. Possible I'm just missing something obvious. I can't pull up the "channel mixer" with images in Lab (it's grayed out).
I can't find any tool in PS to adjust any of the channels in a Lab image (aside from the generic sliders that would also apply to an RBG image). In the standard view I can invert either the a or b channels by using cmd-I. The annoying part is that I may like the image when just seeing the lightness and b channels, but I can't figure out how to export just what I am seeing (as I showed in my previous email). Except I somehow managed to do that once, but can't reproduce it. I don't expect you to teach me PS, but is there still an easy method in the current version of PS to invert either the a or b channels of a pic in Lab and then export it back to LR?
DIGLLOYD: I don’t currently have any infrared camera, though I’d like one.
To eliminate a channel in Photoshop Lab mode: fill the unwanted channel(s) with 50% gray, as shown. This has the same effect as hiding the channel (click the little eye icon to hide/show).
