BINGO! You got to love this list! Based on your remarks Heiko I tested with my Metz 40MZ-2 and SCA3701 adapter, which I used in TTL mode successfully on my PZ_1, but found severe underexposure on my *ist D. All at 200ISO. (On automatic, the flash uses it's own cell, it worked very fine, and the flash gets the focal length of the lens, aperture and ISO setting, so it is still very much automated.)
I redid the test at ISO400 and ISO 800 using TTL, and sure enough, they seem very nice exposed at ISO 400 and perhaps a bit overexposed at ISO800. I was wondering if I needed to upgrade to the SCA3702 adapter, but based on your email that wont be needed nor would it solve it. I wish the manual would have mentioned this. I still can't imagine the reflectivity is a function of the sensitivity of the sensor. If that is indeed not the case, then a firmware update might be possible, well see. So flash at ISO400 when using TTL. Frits On Tue, 2004-01-06 at 11:32, Heiko Hamann wrote: > Hi Bruce, > > on 05 Jan 04 you wrote in pentax.list: > > >Certainly an area that I am most interested in. I am not shooting > >with the AF500FTZ. I have the AF360FGZ and 2 AF400T's and 1 AF280T. > >Could you be a bit more specific about what your results are like? > > There's a German thread on incorrect flash exposures at > http://www.digitalfotonetz.de/phpBB2/viewtopic.php?t=4997&highlight= > > A source at Pentax Germany has explained that there exists a problem > with the TTL-metering (I only repeat some statements of the mentioned > link): The TTL-sensor measures the light that is reflected from the > CCD's surface. But it seemes, that the reflection of the CCD differs > depending on the chosen ISO setting. The exposure will be correct only > at ISO400 as the development and testing of the TTL-measurement was > apparently made at ISO400, only. > > At ISO settings below 400 the camera will under-expose, at setting above > 400 it will over-expose. > > This problem can probably not be solved by a firmware update as there is > no upgradeble TTL-software but some kind of hardware solution. The > problem does not exist if you use P-TTL. > > I didn't try that myself (although I have an AF500FTZ I'm not a great > flash user), but maybe this informations brings some light into the > flash behaviour of the *istD. > > > Cheers, Heiko -- Frits W�thrich <[EMAIL PROTECTED]>
