[Kmier]

Alex,

Thanks for the guidance. Since I don’t have a false back, I ran a sacrificial (de-filmed) roll several times through the camera. I found that any time I have the lens set to “A”, the camera will always drive it to f22 upon exposure (shutter speeds seem appropriate). Otherwise, with any of the AUTO F- -, M, 60, B, settings (with a lens aperature physically set), I get normal action.

Does this still point to goofed-up camera electronics in the AUTO modes? I spent the afternoon yesterday shooting handheld in “M” mode in one of my favorite local Alabama canyons (Dismals Canyon) with Portra 400, so I’m hopeful I finally got some decent shots. My 16 year old son (shoots an Oly E-M5II) commented on how much fun it looked to shoot (vintage sounds and all!).

Manual mode is the way I’ll move forward, if I can get consistent results. Maybe now I can start to look at a couple of extra lenses.

Thanks again.

[Alex645]

Alex,
I found that any time I have the lens set to “A”, the camera will always drive it to f22 upon exposure (shutter speeds seem appropriate). Otherwise, with any of the AUTO F- -, M, 60, B, settings (with a lens aperature physically set), I get normal action.

Does this still point to goofed-up camera electronics in the AUTO modes?

Manual mode is the way I’ll move forward, if I can get consistent results. Maybe now I can start to look at a couple of extra lenses.

IDK. I could imagine reasons why it's the lens or the camera, but I don't have experience with this exact problem and to me, it could still be caused by either the camera or the lens. With 70% rubbing alcohol and a cotton swab, make sure both metal contacts on the lens mount of the camera and the camera mount on the lens are clean.

For sure, the immediate solution is shooting in manual mode, but other options to consider:

a) Here's the forum member map: Worldwide Pentax User Map - PentaxForums.com Do a little digging into profiles and see if anyone within driving distance also has a 645 lens and meet up with them so you can try a different lens on your camera.

b) Buy a second lens for your 645. You can get a 645 200mm f/4 in excellent condition (with 180 warranty) for only $94 Pentax 200mm F/4 SMC A Lens For Pentax 645 System {58} at KEH Camera Store

For $168 you can get the 150mm f/3.5 which is a higher IQ telephoto Pentax 150mm F/3.5 SMC A Lens For Pentax 645 System {58} at KEH Camera Store
$278 for a 75mm f/2.8....my second favorite lens Pentax 75mm F/2.8 SMC A Lens For Pentax 645 System {58} at KEH Camera Store
Or go for broke for $600 on my favorite lens, the 35mm f/3.5 Pentax 35mm F/3.5 SMC A Lens For Pentax 645 System {77} at KEH Camera Store

c) KEH also does repairs on medium format cameras and lens. $265 for the camera, $255 for the lens. If you sent them both, they probably would just fix the one that they found dysfunctional. Personally, I wouldn't go with this option unless you find shooting in manual mode a deal breaker and "a" or "b" above is not an option for you.

[Kmier]

Thanks, Alex645.

I’m just fine with manual - part of the experience, as it were. If I can just get a few good shots for motivation, now that I understand what’s happening, I’ll go hunting the 75mm, and possibly the 35mm. I am liking the view and the feel of the 45mm for now, though.

I appreciate your troubleshooting help!

[Kmier]

Got my pictures uploaded today, from “The Darkroom”. Everything looks great in manual mode, and I prefer that anyway! Perfectly exposed test photos.

I tried cleaning the camera-to-lens electrical contacts, to no avail, but that’s ok.

Looking forward to spending some quality time now!