40D - Highlight Tone Priority

I was wondering if anybody tried how that works for highlights underwater.

What exactly does this mode do?

http://www.kenrockwell.com/canon/40d/highlight-rendition.htm

Probably cut the CMOS sensor's amplifiers one stop on a localized basis.

Ken Rockwell's reports are about as useful as tits on a bull: Photos of holding white lace (think bride & groom) while holding shadow detail of a tux is about the most demanding scene that be shot.

Fuji fixed the problem with their r+s pixel architecture a couple years ago with the (now discontinued) S3 Pro... Which is why the wedding photo crowd switched to them almost overnight when they came out (at least the wedding photogs who use the labs I provide support to).

I was wondering if anybody tried how that works for highlights underwater.

What exactly does this mode do?

 

http://www.kenrockwell.com/canon/40d/highlight-rendition.htm

Ken Rockwell's reports are about as useful as tits on a bull

Now there's a surprise . . .

I was wondering if anybody tried how that works for highlights underwater.

What exactly does this mode do?

Well I've only tried it few times with my 40D and to my untrained, amateurish eyes, I don't see much difference (I shoot RAW only). If you use CS3, I think you might have better luck using the recover slider for blown out shots.

The one thing I do see is that the shadows can get noisy. Will be interesting, once the housing start coming out, to see how it does on sunbursts but I don' expect miracles...