Originally posted by clackers I sense you're confused.
You're really condescending.
By changing the aperture I also control DOF, besides the quantities of light.
Imagine yourself in a situation please, you want to shoot your fast lens wide open outdoors in the harsh sun with a little fill flash, you also want top IQ so you want base ISO. Sometimes you might want to stop down a smaller aperture depending on the shot. We're looking to shoot in the fastest way possible.
In this scenario, we're looking to keep both f-stop and ISO constant. So you really have two choices, Manual or Aperture Priority modes.
Av mode with HSS enabled will keep the shutter speed above an appropriate level (>1:1 w/ focal length) when the ambient light dips forcing the flash to a slow-synchro, or go all the way to 1/8000s if the ambient light dictates. The flash is always giving an appropriate amount of fill for whatever aperture you want, while exposing perfectly for ambient too. All you need to concern yourself with is composition, focus, and Av value, unless there is an aspect of the shot where you desire a certain shutter speed too.
Manual mode does none of that, I always have to watch the exposure meter and tweak shutter speed accordingly. While as a photographer I know when it is HSS or Slow-Synchro, the flash is actually perfectly capable of making that distinction too. Moving the shutter speed around in M doesn't take much time, but it is more work than Av.
You'll find most photographers can appreciate an automated system when it works well, M is not the only choice on the dial for good reason: it's what the market wants.
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Regarding the A lens, why does the system work on K-5/K-5II without subject distance, but not K-1? Can subject distance not be estimated from focus confirm?
Open your mind a little. There is conflicting evidence of how the system works and has worked with an A lens, so Ricoh should investigate it further. Medex expected the camera to work like his previous one, now it doesn't. This is a classic support issue/bug that Ricoh should address.