Originally posted by JohanBene The even number of focuspoints and the x-sync depending on flash makes this sound fishy
The flash thing is actually plausible.
Pentax lists the AF540's flash duration at approximately ¹⁄₁₂₀₀ seconds at full power. But that's the T.5 duration — the time in which the light output is at least half of the brightest level. The T.1 duration (time in which light is at least 10% of peak) for Metz's 48 AF-1 and 58 AF-1 flashes is only ¹⁄₁₂₅. Pentax doesn't list T.1 times, and Pentax USA doesn't know what they are. (Someone could measure, but I don't have the right equipment.) It may be that Pentax feels that faster than ¹⁄₁₈₀ is simply cutting it too close with the existing flashes.
New flashes could have a shorter full impulse, allowing shorter shutter speed. (Although presumably ¹⁄₂₅₀
should be available on older flashes at reduced power, maybe that's too much complication.)