L*a*b Mode question

[Craig_Cooper11664875449]

Using PS 7, With an image in Lab mode is it possible to get back to an RGB mode

without the Lab "a" channel? That is, keep the Lab monitor result with the "a"

channel turned off.

[colinsouthern]

I don't think so. With CS2, if you delete the "A" channel then CS2 represents the two remaining channels as Alpha 1 7 Alpha 2 - if you simply turn off the A channel then convert back to RGB then CS2 turns the channel on during the conversion.

 

Why not just add a curves layer - flatline the "A" channel curve - flatten the image - and convert back from there?

[Craig_Cooper11664875449]

Thanx Collin,

 

Ive been continuing to play since I posted this and have worked out how to do it. While in Lab go to Levels, select "a" channel, then set both sides of the "Output levels" sliders to 128. "a" channel is effectively turned off!

[colinsouthern]

You're welcome - your way and my way are actually doing the same thing - changing the tone mapping for that channel.

[will_hammond]

Filling the "a" channel with 50% gray would do the same thing