K-30 causing random under exposures

qwertyazerty · 06-13-2013, 01:17 PM

Ok, what the hell?

I've used my K-30 for about a year now and a couple of months ago it started causing some under exposed images (about 20-40%) with my A-series 50mm F1.4. Ok, I thought, it's an old lens and maybe the aperture blades are sticky or something. Too bad.

Then it started to do the same with my A 28mm F2.8. Again, I thought, it's an old lens. Shame, but no reason to get it fixed since the repair would cost twice what the lens is worth.

Now though, I'm starting getting these random under exposed images with my 18-55mm WR kit lens, which basically hasn't been used since I bought the camera!

Some observations:
1. The problem (under exposed images) are MUCH likely to occur with the larger aperture 50mm F1.4
2. The problem occurs much more likely when shooting vertical.
3. It's usually the first image that turns out under exposed. For example, say I've set up a shot and press the shutter button. I do a quick check and see the picture is almost black. I take 3-5 more shots and they all turn our fine.
4. It does not occur at all, in any situation, when using my DA* 50-135mm.

My theory is that the lever inside the camera which controls the aperture control lever on the lens is getting stuck or sometimes doesn't have enough power to keep the aperture open at the correct setting, but instead ends up closing it completely. Either that or the lever is actually slipping for what ever reason.

I've tried cleaning the contacts (which is kind of a moot point since the problem started with the old manual lenses anyway), I've reseted the camera to default settings, I've formated the cards, I've switched cards. I've basically tried everything I can think of.

I'm about to send the camera in for repairs as it is under warranty, but before I do, just want to ask if anyone else has ever experienced anything like this?

Ole · 06-13-2013, 02:23 PM

If the stop down lever is faulty and moves too far one would think that you would also get occasional underexposed images with your 50-135.

But since three lenses out of four exhibits the issue it's bound to be the camera. Perhaps send one of the lenses in with the camera so that the repair shop can test the combo?

qwertyazerty · 06-13-2013, 08:58 PM

I did some google searching and found these two threads:
https://www.pentaxforums.com/forums/general-technical-troubleshooting/187613-...exposed-2.html
https://www.pentaxforums.com/forums/general-technical-troubleshooting/150836-...tos-black.html

I have the exact same problem. Seems I have to send it in for repairs then... *sigh*

qwertyazerty · 08-06-2013, 07:01 AM

Just to update to who ever might find this thread in the future. The problem was a faulty aperture control unit inside the body and the camera was replaced under warranty.

Also, now that I have the new body, I noticed that there is no longer a squealing grinding sound when taking pics. So if your camera is squealing then maybe it's time to take a look at it before it goes to hell.

Last edited by qwertyazerty; 08-06-2013 at 07:06 AM. Reason: squealing sound

midero · 08-18-2013, 06:44 AM

Take a look at this thread.
https://www.pentaxforums.com/forums/general-technical-troubleshooting/229294-...problem-2.html
I have the problem with one of my two K30s. It developed about a year after I got it. Appears that it is the aperture control in the camera.
Mike

visualeuphoria · 08-21-2013, 09:24 AM

hmmm never encountered this issue

06-13-2013, 01:17 PM	#1
qwertyazerty Junior Member Join Date: Aug 2012 Photos: Albums Posts: 33	K-30 causing random under exposures Ok, what the hell? I've used my K-30 for about a year now and a couple of months ago it started causing some under exposed images (about 20-40%) with my A-series 50mm F1.4. Ok, I thought, it's an old lens and maybe the aperture blades are sticky or something. Too bad. Then it started to do the same with my A 28mm F2.8. Again, I thought, it's an old lens. Shame, but no reason to get it fixed since the repair would cost twice what the lens is worth. Now though, I'm starting getting these random under exposed images with my 18-55mm WR kit lens, which basically hasn't been used since I bought the camera! Some observations: 1. The problem (under exposed images) are MUCH likely to occur with the larger aperture 50mm F1.4 2. The problem occurs much more likely when shooting vertical. 3. It's usually the first image that turns out under exposed. For example, say I've set up a shot and press the shutter button. I do a quick check and see the picture is almost black. I take 3-5 more shots and they all turn our fine. 4. It does not occur at all, in any situation, when using my DA* 50-135mm. My theory is that the lever inside the camera which controls the aperture control lever on the lens is getting stuck or sometimes doesn't have enough power to keep the aperture open at the correct setting, but instead ends up closing it completely. Either that or the lever is actually slipping for what ever reason. I've tried cleaning the contacts (which is kind of a moot point since the problem started with the old manual lenses anyway), I've reseted the camera to default settings, I've formated the cards, I've switched cards. I've basically tried everything I can think of. I'm about to send the camera in for repairs as it is under warranty, but before I do, just want to ask if anyone else has ever experienced anything like this?

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06-13-2013, 02:23 PM	#2
Ole Administrator Join Date: Sep 2006 Location: Copenhagen, Denmark Photos: Gallery \| Albums Posts: 4,408	If the stop down lever is faulty and moves too far one would think that you would also get occasional underexposed images with your 50-135. But since three lenses out of four exhibits the issue it's bound to be the camera. Perhaps send one of the lenses in with the camera so that the repair shop can test the combo?

06-13-2013, 08:58 PM	#3
qwertyazerty Junior Member Join Date: Aug 2012 Photos: Albums Posts: 33 Original Poster	I did some google searching and found these two threads: https://www.pentaxforums.com/forums/general-technical-troubleshooting/187613-...exposed-2.html https://www.pentaxforums.com/forums/general-technical-troubleshooting/150836-...tos-black.html I have the exact same problem. Seems I have to send it in for repairs then... sigh

08-06-2013, 07:01 AM	#4
qwertyazerty Junior Member Join Date: Aug 2012 Photos: Albums Posts: 33 Original Poster	Just to update to who ever might find this thread in the future. The problem was a faulty aperture control unit inside the body and the camera was replaced under warranty. Also, now that I have the new body, I noticed that there is no longer a squealing grinding sound when taking pics. So if your camera is squealing then maybe it's time to take a look at it before it goes to hell. Last edited by qwertyazerty; 08-06-2013 at 07:06 AM. Reason: squealing sound

08-18-2013, 06:44 AM	#5
midero New Member Join Date: Dec 2010 Location: Des Moines, Iowa Posts: 24	Take a look at this thread. https://www.pentaxforums.com/forums/general-technical-troubleshooting/229294-...problem-2.html I have the problem with one of my two K30s. It developed about a year after I got it. Appears that it is the aperture control in the camera. Mike

08-21-2013, 09:24 AM	#6
visualeuphoria New Member Join Date: Aug 2013 Posts: 2	hmmm never encountered this issue