Originally posted by Topsy Also, I believe that if you're using old lenses the flash will always fire on full power without you being to change it. (unless I'm doing something severly wrong)
This is
only true for lenses without the "A" contacts (no A position on aperture ring). P-TTL is available for lenses having the "A" contacts. While the body is able to control the flash using P-TTL for all "A" contact lenses, the ability for it to do so over a wide range of ISO, distance, and aperture settings depends on whether the whether the data pin is present (all AF lenses) as well as the data protocol generation employed. The rule of thumb to use with Pentax-A (non-AF, A-contact) lenses is to avoid wide apertures, high ISO, and close distance. With AF lenses consistent exposure should be easier to attain.
Steve