[coralwild]

Before I start down the lengthy & probably very expensive camera repair shop route, I hope that someone may be able to help me.

I've had my K10D since May 2007 and use it in my everyday work as a safari guide (I average around 8,000 exposures a year) and have never had any problems with it.

A few months ago I bought the Sigma DC 18-250mm HSM super zoom to replace my 30 year old Kiron 80-200mm zoom lens as my everyday, everywhere, standard safari lens. No problems so far with that switch.

3 weeks ago I suddenly started experiencing over exposure problems - mostly with wider angle shots and especially in bright light conditions. I was on a working trip at the time so didn't have much time to troubleshoot, just muttered and cursed under my breath and kept on taking more exposures at different settings hoping that some would come out okay.

In the last few days I have tried out my 3 different lenses (the pentax kit lens, the manual Kiron lens and the sigma) and have the same problem with all 3. No matter what the aperture is set to and displayed on the LCD, or set on the aperture ring of the Kiron, or recorded on the JPG, the resulting exposure is the same for a given fixed shutter speed + ISO speed.

Examples: 1) program mode Tv; Exposure bracketing set = 3, 1.0; shutter speed is 1/125, f-stops - 8, 11, 5.6; result - NO difference in exposure

2) program mode Av; exposure bracketing set = 3, 1.0; shutter speeds 1/90, 1/180, 1/45; f-stop 9.5; result - expected differences in exposure

In the short term I can still use the camera but am obviously limited in bright conditions as the aperture seems to be fixed quite wide open
and I cannot manipulate depth of field.

I had been playing around a little with settings, but have reset on the Custom menu to the defaults & it has made no difference to the problem.

Any suggestions on what else I could try?

[drougge]

Maybe the little aperture lever in the mount is just stuck and you can get it loose with your finger. More likely something is wrong with the motor for it, but it's worth a try. It's on the left side when looking into the mount, and you should be able to move it upwards smoothly but with a fair bit of resistance.

[octavmandru]

Well, if I'm not mistaken, you can try to check if the camera aperture actuator is actually moving. M mode, Aperture ring allowed.
Just take the lens out, and look in the mount, on the left side of the mirror. Then pres the shutter button.
It should go up in the same time with the mirror.

Octav

[coralwild]

Thanks for the suggestion. The aperture lever only moves with very firm pressure & it doesn't move smoothly, it sounds as if it is on a ratchet - is that what it should sound like?
Having moved it up and down, and remounted my lens there has been no change.

[coralwild]

octavmandru;1662390]Well, if I'm not mistaken, you can try to check if the camera aperture actuator is actually moving. M mode, Aperture ring allowed.

Thanks Octav. Tried this and the lever / actuator doesn't move when pressing the shutter button.

Does it sound as if the repair shop is my next option?

[octavmandru]

Well... One way is to keep your camera for M42 lenses.
You should check the price for a repair, but most likely a used k10 is the answer.
Or a new K-5...

[JeffJS]

Before you send it off (it will probably cost more to fix than replace the camera from past anecdotal experience), check and see if the spring on the aperture lever has come loose. I have read here more than a few times that it Can and does happen. This may help you navigate around inside the camera..

Downloads

[coralwild]

Thanks for all the suggestions I will have a look at the manual Jeff & see if a non-teccie like me can see anything obvious. Will feedback later......