What is the preferred method?

[Derrel]

Shoot in RAW + JPEG mode, with JPEG set to Large size, Fine quality compression, and in-camera sharpening set fairly high in 'most cases'. Set the tone curve to the appropriate level for the subject matter and the lighting; ie, in low-contrast,flat light, set the contrast to Nigh or Medium-High. In very high-0contrast lighting scenarios, set the tone curve lower, to "Low" contrast. If you have a Canon d-slr, set the Filter Effect control to "Yellow Filter" for most subjects, or to Red Filter or Orange Filter for skyscapes and some seascapes. Set the the image toning to Cold-Tone, or to Sepia Tone if you like.

Why? This gives in-the-field B&W preview images, and they are already sharpened and the tone curve is set appropriately, and the camera's metering analysis can apply some processing choices based on color measurements and the filter effect, and also can apply image toning, like the Sepia Tone Effect, for example. You get to literally SEE the way the light will be rendered IN BLACK AND WHITE, in the field or in the studio, and in many cases, the images a good,modern d-slr make will be pretty good B&W images. If a person wishes to make B&W images, then the lighting needs to be optimal for B&W. B&W is about line,shape,mass,pattern,and dissonance...it has no "color", and the lighting ratios that look best in B&W are much,much,much higher than those optimal for color.

THe second benefit...you will have full bit depth RAW images, in full RGB color, available for maximum potential processing effects later, as needed. As well as IN-camera B&W "originals". Originals which if shot as described above, will look pretty damned good out of any Canon made since the 20D. Some of the Nikons I have owned have made some incredibly lovely B&W medium-sized JPEG images, with the down-sampled in-camera images looking quite beautiful. The ancient Nikon D1 for example, made awesome B&W Medium JPEGs.

 

[duhast]

Thanks, I saved that, and actually understood much of it...

 

[The_Traveler]

it is about control. Would I be correct in saying that the control the computer gives is even beyond that of, say, Ansel Adams and his mastery of the zone system? More manipulation is possible with digital than with film and chemicals?

Having been a devotee of the Zone System previously, I am confident in saying a loud yes.
The zone system works in generalities and then the necessary darkroom effort aims more at specifics. But at each step you have essentially foreclosed on most prior decisions (you can't undevelop a negative or un-burn a corner).

Digital allows the user to make and try an essentially infinite number of possibilities with much less waste of time and much more flexibility.