Extremely dark pictures from k-x, wasn't like this before

SOldBear · 04-30-2011, 10:29 AM

Please read this thread. Your problem may be similar.

A symptom that doesn't match is that with the K10D, the viewfinder is darker than normal (that's why I asked the question). But this behavior may be different with your K-x. The surest way is to check the aperture actuator lever on the camera.

mobiuspizza · 05-01-2011, 05:08 AM

Thanks. I think I know the partial cause.

The apeture actuator, which is a linear motor controlling a flap which moves during shutter release, pushing the apeture lever in the lens in process, seemingly ignores the F-stop setting. It is on the left of the camera when looking into the inside from front.

I manually blocked the lens lever so that the minimum apeture is bigger, and that produced brighter picture.

However, I cannot verify this is the case because after one removes the lens, the F-stop setting is unavailble. I can see however the actuator moves full step all the time. If it is to obey a F4 setting, it should not do so.

The cause of it ignoring the setting is unknown however.

I cleaned the contacts, and there seemingly is a contact on the lens contact ring on the camera, the fifth from vertical bottom when counting counter-clockwise. It looks depressed but at the same time looks like a different contact type. So I am not sure whether that is normal.
The others looks like steel spheres in holes, but the fifth one is a sunken flat pillar.

mobiuspizza · 05-01-2011, 05:18 AM

Originally posted by SOldBear

Please read this thread. Your problem may be similar.

A symptom that doesn't match is that with the K10D, the viewfinder is darker than normal (that's why I asked the question). But this behavior may be different with your K-x. The surest way is to check the aperture actuator lever on the camera.

Thanks, that's very relevant.
I was reading your reply number 6
What's a DOF button?

Currently the actuator lever is very firm. I cannot move it. If it's controlled by a linear motor without spring mechanism on a k-x then that's normal that I cannot move it. Can't see a spring either

K57XR · 05-01-2011, 09:30 PM

Originally posted by mobiuspizza

What's a DOF button?

If I'm not mistaken I believe this is the Green button assigned for Optical Preview on the K-x...pages 124-126 of the K-x manual.

mobiuspizza · 05-02-2011, 05:40 AM

Thx, not much help since optical preview only works with lens attached. But I can see now that even in viewfinder the image is darkended in optical preview, and that F-stop settings has no effect on brightness.

I can't see what's wrong with it, I guess I will have to phone Pentax. I hope it won't be expensive. Warranty just expired.
There is 1 year warranty only, I think that's a bit short in this year and age :/

Zafar Iqbal · 05-02-2011, 06:14 AM

I have to ask - you don't have a filter on the lens, eh? :P

mobiuspizza · 05-03-2011, 02:33 AM

erm yes and no. Yes cause it has a UV filter, and always had been there. No cause it won't dim the picture like that lol

Dr_who · 05-04-2011, 09:24 AM

do you have another lens/body to swap and see if problem follows one or the other?

mobiuspizza · 05-05-2011, 02:42 AM

Originally posted by Dr_who

do you have another lens/body to swap and see if problem follows one or the other?

Thanks. Well I've already mentioned that I have tried 2 lens and I am very sure it's not a lens problem.

malcallm · 07-05-2013, 02:41 PM

I'm aware that this topic is 2 years old

, but did you solve this problem? I have the same issue with my K-30 + kit lens. Problem is so rare I found only 3-4 mentions about it, but such I know that is not just fault of my camera, but rather some very-rare-but-repeatable-error

mobiuspizza · 07-06-2013, 03:13 AM

malcallm yes, I have to take it back to a repair shop. Basically the motor that controls the apecture flap was broken and they just had to replace that.

malcallm · 07-06-2013, 04:02 AM

Meh, it looks serious then

I was hoping that it's some lens problem or connection between lens and camera... It looks like Pentax didn't manage to fix this in new cameras: https://www.pentaxforums.com/forums/general-technical-troubleshooting/229294-...e-problem.html

Thanks for replying!

ToyTank · 07-10-2013, 07:39 AM

I had a similar problem, I think from mounting a Pentax-M 50/2 on my K-30. The lever on the lens to keep aperture open was rigid, and I think it damaged the actuator on the camera.

I'm not sure if this is normal for a "M" lens, but I thought any Pentax K mount should be compatible and not damage the body.

I called Costco, they replaced it and paid to send my damaged one back to Pentax, even though I told them I suspected I damaged it. That is why I shop costco.

Now I inspect every lens before I use it.

malcallm · 07-10-2013, 12:21 PM

I can't see any damage in my camera. Actuator looks ok and clean, so I suppose there's problem with motor itself or some electronics.

stardog79 · 11-02-2015, 04:26 AM

Originally posted by mobiuspizza

malcallm yes, I have to take it back to a repair shop. Basically the motor that controls the apecture flap was broken and they just had to replace that.

Hi, Sorry if I use this old post but I could not find many on the internet.
I have the very same problem on a pentax k-500. I am just curious to know how much did it cost to repair the camera.

Many thanks

05-01-2011, 05:18 AM	#18
mobiuspizza New Member Join Date: Apr 2011 Posts: 14 Original Poster	Originally posted by SOldBear Please read this thread. Your problem may be similar. A symptom that doesn't match is that with the K10D, the viewfinder is darker than normal (that's why I asked the question). But this behavior may be different with your K-x. The surest way is to check the aperture actuator lever on the camera. Thanks, that's very relevant. I was reading your reply number 6 What's a DOF button? Currently the actuator lever is very firm. I cannot move it. If it's controlled by a linear motor without spring mechanism on a k-x then that's normal that I cannot move it. Can't see a spring either Last edited by mobiuspizza; 05-01-2011 at 05:26 AM.

07-10-2013, 07:39 AM	#28
ToyTank Veteran Member Join Date: Mar 2013 Photos: Albums Posts: 675	I had a similar problem, I think from mounting a Pentax-M 50/2 on my K-30. The lever on the lens to keep aperture open was rigid, and I think it damaged the actuator on the camera. I'm not sure if this is normal for a "M" lens, but I thought any Pentax K mount should be compatible and not damage the body. I called Costco, they replaced it and paid to send my damaged one back to Pentax, even though I told them I suspected I damaged it. That is why I shop costco. Now I inspect every lens before I use it. Last edited by ToyTank; 07-10-2013 at 07:44 AM. Reason: Info

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04-30-2011, 10:29 AM	#16
SOldBear Veteran Member Join Date: Feb 2009 Location: Alameda, CA Posts: 3,206	Please read this thread. Your problem may be similar. A symptom that doesn't match is that with the K10D, the viewfinder is darker than normal (that's why I asked the question). But this behavior may be different with your K-x. The surest way is to check the aperture actuator lever on the camera.

05-01-2011, 05:08 AM	#17
mobiuspizza New Member Join Date: Apr 2011 Posts: 14 Original Poster	Thanks. I think I know the partial cause. The apeture actuator, which is a linear motor controlling a flap which moves during shutter release, pushing the apeture lever in the lens in process, seemingly ignores the F-stop setting. It is on the left of the camera when looking into the inside from front. I manually blocked the lens lever so that the minimum apeture is bigger, and that produced brighter picture. However, I cannot verify this is the case because after one removes the lens, the F-stop setting is unavailble. I can see however the actuator moves full step all the time. If it is to obey a F4 setting, it should not do so. The cause of it ignoring the setting is unknown however. I cleaned the contacts, and there seemingly is a contact on the lens contact ring on the camera, the fifth from vertical bottom when counting counter-clockwise. It looks depressed but at the same time looks like a different contact type. So I am not sure whether that is normal. The others looks like steel spheres in holes, but the fifth one is a sunken flat pillar.

05-01-2011, 09:30 PM	#19
K57XR Veteran Member Join Date: Feb 2011 Location: Colorado, USA Posts: 830	Originally posted by mobiuspizza What's a DOF button? If I'm not mistaken I believe this is the Green button assigned for Optical Preview on the K-x...pages 124-126 of the K-x manual.

05-02-2011, 05:40 AM	#20
mobiuspizza New Member Join Date: Apr 2011 Posts: 14 Original Poster	Thx, not much help since optical preview only works with lens attached. But I can see now that even in viewfinder the image is darkended in optical preview, and that F-stop settings has no effect on brightness. I can't see what's wrong with it, I guess I will have to phone Pentax. I hope it won't be expensive. Warranty just expired. There is 1 year warranty only, I think that's a bit short in this year and age :/

05-02-2011, 06:14 AM	#21
Zafar Iqbal Veteran Member Join Date: Oct 2010 Photos: Gallery Posts: 1,229	I have to ask - you don't have a filter on the lens, eh? :P

05-03-2011, 02:33 AM	#22
mobiuspizza New Member Join Date: Apr 2011 Posts: 14 Original Poster	erm yes and no. Yes cause it has a UV filter, and always had been there. No cause it won't dim the picture like that lol

05-04-2011, 09:24 AM	#23
Dr_who Veteran Member Join Date: Jun 2009 Location: Edmonton, Alberta, Canada Photos: Gallery \| Albums Posts: 777	do you have another lens/body to swap and see if problem follows one or the other?

05-05-2011, 02:42 AM	#24
mobiuspizza New Member Join Date: Apr 2011 Posts: 14 Original Poster	Originally posted by Dr_who do you have another lens/body to swap and see if problem follows one or the other? Thanks. Well I've already mentioned that I have tried 2 lens and I am very sure it's not a lens problem.

07-05-2013, 02:41 PM	#25
malcallm New Member Join Date: Jul 2013 Posts: 9	I'm aware that this topic is 2 years old , but did you solve this problem? I have the same issue with my K-30 + kit lens. Problem is so rare I found only 3-4 mentions about it, but such I know that is not just fault of my camera, but rather some very-rare-but-repeatable-error

07-06-2013, 03:13 AM	#26
mobiuspizza New Member Join Date: Apr 2011 Posts: 14 Original Poster	malcallm yes, I have to take it back to a repair shop. Basically the motor that controls the apecture flap was broken and they just had to replace that.

07-06-2013, 04:02 AM	#27
malcallm New Member Join Date: Jul 2013 Posts: 9	Meh, it looks serious then I was hoping that it's some lens problem or connection between lens and camera... It looks like Pentax didn't manage to fix this in new cameras: https://www.pentaxforums.com/forums/general-technical-troubleshooting/229294-...e-problem.html Thanks for replying!

07-10-2013, 12:21 PM	#29
malcallm New Member Join Date: Jul 2013 Posts: 9	I can't see any damage in my camera. Actuator looks ok and clean, so I suppose there's problem with motor itself or some electronics.

11-02-2015, 04:26 AM	#30
stardog79 New Member Join Date: Nov 2015 Posts: 1	Originally posted by mobiuspizza malcallm yes, I have to take it back to a repair shop. Basically the motor that controls the apecture flap was broken and they just had to replace that. Hi, Sorry if I use this old post but I could not find many on the internet. I have the very same problem on a pentax k-500. I am just curious to know how much did it cost to repair the camera. Many thanks