Hello Stefan, Stefan Ittner wrote:
> There seems to be a consensus in this group that the *ist will be > able to to work with M-lenses if the exposure is adjusted when not > shot wide open (e.g. 2.8 lens shot at 5.6 => tell camera to overexpose > by 2 stops). But what about flash pictures shot in TTL mode? AFAIK, > here the camera measures the light that actually reaches the film > plane and turns off the flash as soon as the correct exposure is > reached. Therefore, metering will also work properly for _stopped-down_ > M lenses. This should at least work if you photograph in total > darkness (right?). Congratulations on your excellent understanding of the K-mount and your _VERY_ clean thinking!!! I think that what you say is absolutely correct. > But what if there is also some (or lots of) ambient light? > I guess that the camera normally takes into account when shutting > off the flash that some more light will reach the film plane before > the shutter closes again, as the flash normally fires just after > the shutter is fully open. I am not sure. It is, of course, easier to just ignore the problem, and I imagine that in the beginning TTL systems did. Modern systems might actually underexpose the flash some so that the ambient light does not lead to a combined overexposure. In any case, I _GUESS_ that if you set the exposure manually (not using the exposure compensation dial), you will get properly exposed images, both with and without flash. If you set exposure via the exp. comp. dial you will get properly exposed ambient images but overexposed flash images. > Does anyone have some experience how the MZ-50, which also has a > crippled KAF mount, reacts in these circumstances? I am quite certain that the results from an MZ-50 and *ist will be the same, so if someone makes a test, we will know... ------------------------ Back to Arnold Stark's idea. If the *ist does DOF properly with K and M lenses and is able to combine DOF preview with exp. lock, then even most of the inconvenience of the crippled mount is solved. You simply press exp. lock WHILE HOLDING the DOF preview button. This is a great idea that does not cost Pentax anything in hardware and almost totally overcomes the limitations of the crippled mount, so it will be inexcusable if they did not implement it. On the other hand, even this will not work for flash exposures... Cheers, Boz
