Originally posted by MJL I have K7 & AF280T - the flash definitely will not work in "TTL Auto" mode with K7. You should also check ISO setting on the K7 when using the red or green "Auto" mode, as K7 cannot communicate its' settings to AF280T.
in that case it appears that K-7 went dumber than K10D!
Because K10 and AF280T do communicate to certain extent. Yes, the TTL auto will not work, because newer Pentax bodies do not recognize the TTL protocol and need P-TTL. In TTL the camera has separate sensor which measures the light coming in through the exposure and tells flash when to stop, while in PTTL the camera needs preflash to judge the conditions and determine the power and duration of the flash...
anyway, back to topic.
Best way to use AF280T is Sv mode. Why? Well, you slap the flash on camera, select green or red mode, turn it on and turn the camera on and voila..., all you need to care is the ISO. Thanks to communication between camera and flash, with changing of the ISO camera will automatically adjust the f stop (this means you have to have A or later series lens of course) to achieve the correct exposure in flash auto mode...
In other words, flash in red more, camera in Sv @ ISO100 mode will result in f4 with Tv being according to focal length of the lens. Change ISO to the 200 and camera will automatically change the F stop to 5.6... sound funny but yes, you can control your DOF with flash using different ISOs and still be in flash auto mode... One thing though, this only works with direct flash, when you bounce it's all out of the window....
enjoy