I am not able to find the answers for two questions about LAB. Can you help me?
- When in the Layer palette there are some New Adjustments Layers and we want to change from RGB to LAB, PS requires to flatten the layer stack or, at least, the New Adjustment Layers. There is a way to avoid that?
- What is the difference, if there is one, between sharpening and contrasting in the Lightness channel of the LAB Mode and in the Luminosity Blend options of the Layer palette (or Edit>Fade)?
Thanks very much.
Posted by Nat Coalson on November 28, 2008 at 12:27 PM
- When in the Layer palette there are some New Adjustments Layers and we want to change from RGB to LAB, PS requires to flatten the layer stack or, at least, the New Adjustment Layers. There is a way to avoid that?
The best way to do this is to Duplicate > Image, with Duplicate Merge Layers only. Do your LAB work in the new document then bring it back to your master RGB file, as a merged layer, when you're done.
Changing color modes changes the layer blends; that's why Photoshop is trying to get you to flatten/merge. Avoid doing this to your master RGB file if possible; it degrades the image data. I'd recommend NOT going back and forth between RGB and LAB in a single document. Use temporary, working files as necessary instead.
- What is the difference, if there is one, between sharpening and contrasting in the Lightness channel of the LAB Mode and in the Luminosity Blend options of the Layer palette (or Edit>Fade)?
On most photos, both methods produce very similar results. Method 2 is a lot easier.
After working in LAB for a long time I no longer see the need. Working in ProPhoto RGB and using the latest methods for sharpening and color correction make LAB unnecessary in my workflow. I think it's more trouble than it's worth in most cases.
Posted by John Mumaw on November 29, 2008 at 9:15 PM
What is the difference, if there is one, between sharpening and contrasting in the Lightness channel of the LAB Mode and in the Luminosity Blend options of the Layer palette (or Edit>Fade)?
None whatsoever.
Blend and Edit->Fade have the advantage of being non-destructive to your image, unlike converting to LAB and then back to RGB again, especially with 8 bit image files.
Discussion
2 replies- When in the Layer palette there are some New Adjustments Layers and we want to change from RGB to LAB, PS requires to flatten the layer stack or, at least, the New Adjustment Layers. There is a way to avoid that?
- What is the difference, if there is one, between sharpening and contrasting in the Lightness channel of the LAB Mode and in the Luminosity Blend options of the Layer palette (or Edit>Fade)?
Thanks very much.
The best way to do this is to Duplicate > Image, with Duplicate Merge Layers only. Do your LAB work in the new document then bring it back to your master RGB file, as a merged layer, when you're done.
Changing color modes changes the layer blends; that's why Photoshop is trying to get you to flatten/merge. Avoid doing this to your master RGB file if possible; it degrades the image data. I'd recommend NOT going back and forth between RGB and LAB in a single document. Use temporary, working files as necessary instead.
On most photos, both methods produce very similar results. Method 2 is a lot easier.
After working in LAB for a long time I no longer see the need. Working in ProPhoto RGB and using the latest methods for sharpening and color correction make LAB unnecessary in my workflow. I think it's more trouble than it's worth in most cases.
None whatsoever.
Blend and Edit->Fade have the advantage of being non-destructive to your image, unlike converting to LAB and then back to RGB again, especially with 8 bit image files.