I bought a Pentax-M 50mm F2, and I already had a Promaster (Tamron) 80-210 AF that has an aperture ring you can set to A or specifically to a manual set position.
I followed the guide here:
https://www.pentaxforums.com/forums/54-pentax-lens-articles/110657-how-use-me...k-x-k-7-a.html
I also configured everything I believe I am supposed to, although the K-50 specific information is scattered around, so for those running into the same issues I took pictures of the menus. I'm going to make a sort of K-50-specific "guide" to make sure I did it right. If I did, people with K-50's can follow this for a bit more specific help. After that, my issue will be below.
First, turn the auto focus switch to "MF" for manual focus:
Might as well set the E-Dial knob to "M' for manual control:
Next, mount the lens and turn the camera ON. If it was already on, turn it off, and turn it back on. It will prompt you to tell it what size lens this is. On my Pentax-M it's on the front (50mm). Hit "OK" to accept your selection:
Next, hit the menu button and move to the tab option shown. Select E-Dial Programming and press "OK":
On the second page of this next window you want the settings for "M"
This lets you select the exposure mode for "M". We want to modify the function of the green button, move to that and press "OK":
Selet "Tv SHIFT" and press "OK":
The green button is now programmed "Tv SHIFT" for the "M" mode.
Next move to this tab on the main menu, and select item #22 (and press "OK"):
We want to select option #2 which is "Enable" and press "OK":
The use of manual aperture control (an aperture ring) is now enabled.
NOW... to the best of my knowledge, based on what I read in that thread... for the K-50 that's about it!
Except... in my case I get some odd results. I set both the Pentax-M and the Promaster to F16. Both of them came out... weird. I am attaching the files here, but the color is strange. All the extended file info should be there other than of course the F16.
I just need help understanding what is at play here. "M" lets me control ISO, shutter speed, and if I wanted to, brightness. I usually leave that at zero. But I see that pressing the green button takes what I assume is a metering for light, and automatically sets shutter speed (but not ISO). Yes?
Hopefully this end of things can be better explained. I already read through a few big web resources on what stops are, bigger numbers are smaller apertures, and how the numbers on the lens correspond with what effective stops work within a given focal range. So then what am I missing here? :/
Last edited by Suleeto; 01-09-2015 at 05:39 PM.