One of the benefits of Photoshop is its flexibility, esp. when it comes to choices among color --> to --> BW conversions, which range from quick and dirty (Desaturate) to Calculations.
The advantage of Greg's method (once recorded in an action) is efficiency, especially when incorporated into a batch workflow or converted to a droplet. (It was nice of you to type out all the instructions, Greg.)
I used to use plugins like Fred Miranda's BW Workflow Pro (
http://www.fredmiranda.com/shopping/BW) and BW Styler (
http://www.thepluginsite.com/products/photowiz/bwstyler/index.htm). Plugins like these can considerably streamline workflow and have options like the ability to apply various types/amounts of grain and/or duo, tri, quad-tone colors effects.
Channel Mixer (monochrome) is a great tool, too (intuitive, easy to use). I am really looking fwd to trying the new CS3 BW adjustment layer.
As noted in a post above "I most often use the Russell Brown / 2-Hue/Saturation adjustment layer method." I should have qualified that comment with, "...when I'm in a hurry."
If I have time I use a method that I believe affords exceptional flexibility. It is based on an tutorial by John Paul Caponigro:
* Tutorial in .pdf format:
http://www.adobe.com/digitalimag/pdfs/phs8bwconversion.pdf
* PS action:
http://www.adobe.com/digitalimag/downloads/bw-conversion.atn
In it the grayscale versions of the R, G and B channels are layered above a copy of the L channel allowing one to utilize the strengths of any/all the channels (using layer masks) as well as combine them using layer blend modes. It's a cross between the insane flexibility of the Calculations command and selective application using layer masks without the headache of navigating the Calculations dialog.
If you'd like a copy of an action I wrote based on my interpretation of JPC's method, send an e-mail at
[email protected] and I'll be glad to send you a copy.