|
> * Pentax *ist D: Full TTL support for the internal flash and any external TTL flash used with any lens
Nope. RTF of *ist D does not support TTL, it's P-TTL only. Only that MZ-S has TTL for RTF and P-TTL (only) for external flashes.
> * Pentax *ist DS/DS2: TTL support for external TTL flashes only (Must be in M mode for manual lenses or when away from "A." Extremely fast apertures cannot be used)
My experience with setting a FA lens at non-A position did NOT engage TTL mode and exposure was in a mess.
> Sadly, since the DS/DS2's both have the TTL sensor, TTL support for the built-in flash must be disabled via firmware. Also, if P-TTL is available on the external flash, it will be used over TTL.
Yes.
> -P-TTL calculates lighting before exposure using a preflash shot and does not function if the aperture value is unknown.
P-TTL rely heavily on the distance info after AF (probably MF too) completes. So, if there was mis-focusing, the exposure will be off too.
|