Hi George,
Originally posted by eddie1960 been a while since i ised an A but there is a little button you have to depress to move it the rest of the way
Take Eddie's advice, Yes, look for the little button (to left of "A") that will allow you to rotate aperture ring to "A" setting and locked in...
Originally posted by George Wickham Thanks for the replies. I wonder if I'm actually setting the lens to the "A" setting. Looking at the lens, I've rotated the aperture ring as far as it will go in the counter clockwise direction (which spins the green "A" on the dial toward the top. It doesn't go as far as the red hash mark at the top of the lens though). I'm getting the (nonblinking) "F --" on the lcd screen on the top. But the thumb and finger dials don't change the settings. Thanks. George
Also, check one last thing on your K10 settings, under Custom Settings > Using Aperture Ring should be set to #2 Permitted.
I would also inspect lens, take off camera and play around with the aperture ring, you should see aperture changing size, now gently move the aperture lever and you should see the opening go to it's largest size no matter what you have aperture set on... It needs to be able to do this to function properly on your camera (otherwise only max aperture is working).
If you have the lens correctly on the "A" setting, you can use any camera mode on your K10, both front (shutter) and rear (aperture) wheels should work as well as +/- exposure compensation.
You can still use the lens off the "A" setting but only in Manual Mode on your camera by manually setting the aperture and then using the green button so the camera meter can set correct shutter speed. In this case you can always set the shutter speed to compensate for any exposure issues with the front dial but the aperture can only be manually adjusted (and the F___ will be showing on top LCD)
Have fun - Rick