"We're running a week of Bryan's ISO-related tips that will culminate in an ISO-manipulation technique that will knock your socks off!"

I haven't had my socks knocked off in a while, so I went and took a look. Bryan described a technique for 'pushing' digital photos the way we used to push film.

"With RAW you can deliberately record images that are two stops underexposed, and then correct these normally bad exposures in post-processing. It's like push processing that we used to do in the darkroom. You can correct these images so well, in fact, that no one will notice that they were ever too dark to begin with! "

It seemed like alchemy to me. What difference does it make it you push the 2-f/stops in RAW or just raise the ISO before you shoot? Isn't it going to be the same? I wrote Bryan and asked.

In my experience "pushing" ISO 100 two stops produces LESS NOISE than if shot at 400 ISO, BUT and this is an important but, IF one is shooting with the likes of the NEW Nikon D700 or Canon 5D, I would say its foolish to do this since there 400 ISO is as "noiseless" as there 200 and 100 ISO. [T]his idea ONLY works with ISO 100 or ISO 200 but NOT with 400 or greater; for reasons I don't understand. When I try pushing 400 or 800 ISO, (shooting at exposures two stops under exposed) and then attempt to 'correct' the exposure in RAW, the noise increases to an unGodly level; much much worse than the original noise one would expect at these higher ISO's.

As with nearly everything digital, the downside is so low it's worth trying out! If you shoot indoor action, like hockey or basketball, 2-f/stops is a huge advantage. It can be the difference between sharp and blur. Meanwhile, there are lots of great tips in Adorama's 100 and I guarantee you'll learn something which will make you a better shooter.