...I just made an interesting discovery. I switched the red light SCA 374/2 AF adapter on the "faulty" Metz 32 CT3 flash, with a regular SCA-372 adapter. Then the problem was gone. The same adapter was used on the previous test with the Metz 32 Z-2, which performed fine. I even tryed annother SCA 374/2 AF adapter to make sure this wasn't out of order. Same result.
This leads me to this conclusion: Red light AF-Assist don't work right with the *ist D! It may cause the TTL to malfunction. To some extend, at least. Even the "faulty" AF500FTZ has a built-in red light AF-assist. The (correctly working) AF280T doesn't. I have no scientific proof for this (I haven't got a clue about electronics...), but it still strikes me as a plausible explanation. All the best Jens Intersting problem. I just briefly tested 4 TTL-flashes on the *ist D at 200-400-800 ASA (same speed and F-stop) : AF500FTZ Metz 32 CT3 Metz 32 Z-2 Pentax AF280T The two first gave me the same problem as described by Micahael; brighter image, when the ISO setting is turned up. The two next flashes didn't. They gave me correct exposure, regardless of the ISO setting at all three settings. Other than that, I think the AF 500 FTZ works quite well with the *ist D. Red AF assist light and all. That's odd, isn't it? Jens Bladt mailto:[EMAIL PROTECTED] http://hjem.get2net.dk/bladt -----Oprindelig meddelelse----- Fra: Joseph Tainter [mailto:[EMAIL PROTECTED] Sendt: 19. januar 2005 16:24 Til: pdml Emne: Re: flash for *ist D Michael, TTL flashes do not seem to work consistently well with digital SLRs. Some people get good results some of the time, at some ISO settings but not others, with some exposure compensation, etc. The reason is that TTL measures light off the film plane. Of course, a dslr does not have a film plane, so light has to be measured off the sensor. The sensor does not have the same reflectivity as film, so exposures are often inaccurate. P-TTL fires two flashes. The first measures the light bouncing off the shutter to determine the exposure. The second flash illuminates the subject for the photograph. The AF 360 and the Sigma models with P-TTL are both good. The Sigma is more powerful and the head swivels. The Pentax covers a wider angle (24 mm. film/16 mm. dslr) without having to add a diffuser. As for the exposure problems that you noted in another post, try center-weighted metering rather than program metering and see if the results are better. Joe
