I bought a Used Pentax 43 mm recently and although I love the lens, I noticed that occasionally it was a kind of hard to focus. I would see the red Focusing-Point blink on the subject, then Confirmation (green light) at the bottom of the viewfinder would become solid, then I would hear a beep telling me its OK to press the shutter, right. For some reason and I'm not sure if I had too much Coffee that day, the Focusing-Point would suddenly jump out of focus(not by much) while the camera kept trying to focus before I had time to press the shutter, so by the time I hit the shutter button all the way down, the picture was slightly out of focus ?
To remedy this situation I began using the Back AF button on my K5 II and the problem went away. Thank god for that back button because I was thinking about returning the lens ! Since it doesn't happen often and since I got a work-around for it now, I'll save myself the aggravation. I just wanted to post this in case anybody has run into the same thing.
Last edited by hjoseph7; 05-23-2020 at 07:46 AM.