On Mar 13, 2005, at 10:05 AM, Peter J. Alling wrote:
This is what Cotty posted a while back, I thought it was in February but it might have been earlier. (These are Photoshop instructions).
Step 1. Flatten Image
Step 2. Create New Hue/Saturation Adjustment Layer with the following properties:
Mode: Saturation
Hue: -180
Saturation: -100
Lightness: +100
Step 3. Convert to LAB Color. Choose the Flatten Option if given.
Step 4. Open the Channels Window and delete Channels 'A' and 'B'
Step 5. Convert to Grayscale.
Interesting, I tried something similar to that once upon a time. It works well for some images but not for others.
I use the Channel Mixer in Adjustment Layers to do the RGB->monochrome rendering work, normally set to 20% Red, 75% Green and 5% Blue to begin with. Curves tool Adjustment layers below the Channel Mixer layer then allow emphasizing and tweaking the channels individually to get the spectral response where I want it, Curves tool adjustment layers above the Channel Mixer layer then allow selective adjustment on the monochrome image as a whole.
Once I get things where I want them, I save the layer file as a master and then save as to another file where I perform colorspace conversion to Gray Gamma 2.2 for printing; any subsequent edits are tailored to the print needs.
Godfrey
