On Fri, 9 Jul 2004 Harman Bajwa wrote: >> Hi Fred, >> >> Isn't this the case for E-TTL II, >> not for the > original E-TTL? >> The new version uses the distance >> information provided with some >> lenses (mostly ring USM) and reverts >> to standard E-TTL with other lenses. > > Although I am no expert in E-TTL II, > but from what I have read so far, it > seems to me that flash metering > in E-TTL II is different (ie uses a > new or improved way of calculating > required flash exposure) from ETTL > even in the absence of distance > information. If that is true, then > it would be incorrect to say that > E-TTL II reverts to ETTL in the > absence of distance information.
Hi Harman, You're correct, E-TTL II uses a new evaluative metering method even when distance info is not available from the lens in use. The D30 & D60 had a problem with E-TTL to do with the evaluative flash metering linked to the current focus point. Mind you this wasn't the only flash problem, but canon improved flash metering on the 10D by reverting to centre-weighted metering for flash. E-TTL II bodies have re-introduced evaluative metering for the bodies equipped with it, as well as using the distance info available from certain lenses. This metering evaluates the whole frame rather than just the area linked to the current focusing point. I believe it's supposed to remove the need to use FEL when recomposing and helps reduce the impact of highly reflective areas in shot. I didn't mention all that as I was originally trying to make the point that *lenses* don't have e-ttl. Certain Canon lenses can assist E-TTL II by providing distance information to the *camera body* which uses it as part of the flash metering algorithm. However the other component of E-TTL (the improved metering method) is also (from what I hear) a contributing factor in improving flash metering. I probably should have mentioned it. :) Cheers Gary This message has passed through an insecure network. Please direct all enquires to the message author. * **** ******* *********************************************************** * For list instructions, including unsubscribe, see: * http://www.a1.nl/phomepag/markerink/eos_list.htm ***********************************************************
