Use the red channel for skys

rutt

One thing I got from Dan Margulis' class I just took was to always try using a the red channel as a luminosity blend for better skys. Here is a before/after of a shot of PFs.



All I did here was:

• Copy the red channel (preserve the drippings.)
• Convert to LAB
• Duplicate layer
• Substitute that red channel for the L channel in the duplicate layer
• Play with blending options and layer mask to restrict the luminosity blend to the sky.
• Could try steepening the highlights of the luminosity layer to make the sky more dramatic (didn't do this.)

You can tell it's going to work by looking at the red channel before you get going:

pathfinder

John, I have not had time to respond to this post - I THINK I understand what you are saying. I did do a multiply blend on the sky before my first posting and a gradient as well.

You're saying to open and then save to disc a copy of the red channel that has been moved to LAB first. Then reopen the original image, remove the lightness channel and install the first red channel that was saved in LAB. Is this correct?

I am busy processing several portraits I shot yesterday of family members with umbrella lighting and a grey backgound - a first for me - we'll see in a few days.

rutt

I did it differently. I made a copy of the red channel by dragging the red channel down into the duplicate icon. Then converted to LAB. Made a duplicate layer, luminosity blend. Apply image of that copy of the red channel to the duplicate layer's L channel. Then mess around with blending options and layer masks to limit to the sky. Look at how Dan restricts his layer to just the sky in the alpine scene in Chapter 8.

There are plenty of ways to get to the point in LAB where you have the red channel used as a separate layer in luminosity blending mode. The fun starts when you try to restrict to the sky and consider what kind of curve/blend might improve even more.