I'd say it's a combination of everything - the light, perhaps the lens/body, and post processing.
While editing the RAW file in Photoshop, I desaturate the image to my taste and fiddle with Brightness/Contrast (B/C). After saving it as a Tiff file, I use the Shadows/Highlights (usually pulls the Shadows slider all the way to the left, and move up the Highlights slider to my taste). Then I use the B/C to fine tune the contrast to my taste. Finally, after saving it to Jpeg, I wrap up with the KPD Magic Sharpen tool from Kubota for the final pop.