----- Original Message -----
From: "Jack Isidore"
Subject: flash issues with IstD and 500FTZ
I have an istD with 330FTZ, 400FTZ and 500FTZ flashes.
The camera is in green mode and I take flash shots at ISO 200, 400 and
800 ASA all from a tripod, the same subject and the flashes in
auto-TTL mode.
The 200 ISO shots are all underexposed, 400 ISO is more or less
correctly exposed and 800 ISO are all overexposed.
The IstD manual recommends 200-800 ASA for these flashes.
The solution would be to allways use ISO 400 for flash which would be
very strange.
Apparently, on the istD, the TTL flash circuit is optimized for 400 iso.
I have never seen a less accurate TTL flash circuit than the one in the
istD.
Apparently, it's on par with DSLR TTL circuits in general though.
I do find that if I shoot several pictures in fairly rapid succession, the
flash control goes from innacurate to completely inaccurate.
I cured this by stopping usng my TTL flash adaptor, and going back to plain
autoflash.
William Robb
