Originally posted by WalterGA In the K20D manual, the instruction for the Pentax brand flash attachments are to set the camera on either tv or M mode, then set the shutter speed higher than 180.
I'm trying to get the same results with my new Metz 48 AF1, which does have a PTTL HSS setting, and which is supposed to automatically work with dedicated cameras that support HSS.
However, the K20 won't let me set a shutter speed higher than 180 in tv mode...will in M. Am I doing something wrong, or is this an anomaly of the Metz flash unit?
Check if you set Auto EV compensation ON (Custom Menu Item 10 on the K20D), default is OFF.
In normal flash mode, the camera "doesn't care" about shutter speed below 1/180 sec, but if you switch to HSS under Tv, the camera will meter on the ambient lighthing.
In Tv mode & Auto EV compensation ON, the camera will actually prevent you from setting a shutter speed which result in Underexposure at ambient (if you are already at maximum aperture). If the resulting shutter speed is less than 1/180s, it will revert back to normal flash ie. you don't actually have HSS.
Its a bit of a Beginner function to stop you from unintended over/under exposure error, but it gets irritating if you didn't realise its accidentally set on.