[bubobubo]

K-50 here. Following scenarios were all in M-mode.

If I set the Fx button to Optical Preview, if I set an aperture, say f/6.3, I should see a slightly darker image in the viewfinder when pressing the Fx button.
Alternatively, when taking any photo with a preset aperture, say wide-open, when looking in the lens from the front, the aperture closes down to its minimum.

Consequently, all photos are overly underexposed.

The lens is obviously faulty because with an old manual Pentax lens I can take good photos.

I cleaned the contacts with alcohol both on camera and on the lens - it did not fix it.

Whan can I do further?

---------- Post added 08-12-16 at 11:31 AM ----------

I should see a slightly darker image in the viewfinder when pressing the Fx button.

I forgot the essential: but I see instead a very dark image as if the lens closed down to minimum.

[a5m]

Do you have another camera that you can try the lens on? I see this issue brought up often and from the sound of it I think it is the aperture control mechanism in your camera that is faulty. This is a common problem with the K-30 and K-50, and the K-S2 has been reported to have this problem as well.

A forum member stevebrot suggested this method to test the aperture control mechanism:

Welcome to the Pentax Forums. This sort of problem has been reported in the past. Do this simple test to confirm that the aperture mechanism is functioning properly:

• M mode using optical viewfinder (live view off)
• Shutter speed at 3 seconds
• Aperture at maximum for the lens mounted
• While looking into the lens from the front press the shutter release
• Confirm that the lens stays wide open during the exposure

If the lens stops down, there is a fault with the aperture actuator mechanism. This is repairable and is covered if the camera is still under warranty.


Steve

[bubobubo]

No, I don't have another camera.
Well, that's quite bad news as the camera is out of warranty.

[W.j.christy]

Do you have another camera that you can try the lens on? I see this issue brought up often and from the sound of it I think it is the aperture control mechanism in your camera that is faulty. This is a common problem with the K-30 and K-50, and the K-S2 has been reported to have this problem as well.

A forum member stevebrot suggested this method to test the aperture control mechanism:

So the KS-2 now has this failure noted as well? This is the first I have heard of it. I was hoping they would fix this issue to help better the quality of their camera's.

[Adam]

So the KS-2 now has this failure noted as well? This is the first I have heard of it. I was hoping they would fix this issue to help better the quality of their camera's.

I think so, yes. But since the K-S2 is newer, we haven't seen as many occurrences yet.

[a5m]

So the KS-2 now has this failure noted as well? This is the first I have heard of it. I was hoping they would fix this issue to help better the quality of their camera's.

Yes, unfortunately it does. I also hoped that this issue was fixed with the the K-S2. I learned about this recently and it was after I bought my K-S2. A member here started a thread about it, check it out here: Dark frames on K-S2

[stevebrot]

I think so, yes. But since the K-S2 is newer, we haven't seen as many occurrences yet.

IIRC, we started seeing K-30/K-50 issues as the cameras reached about 1 year post-sale. The K-S2 does use a similar aperture control block design to the other two cameras, but then so did the K-r, K-x, K-m, K20D, K10D, etc. I would be pleased as punch if the K-2S and subsequent consumer-line bodies are free of this gremlin.

Yes, unfortunately it does. I also hoped that this issue was fixed with the the K-S2. I learned about this recently and it was after I bought my K-S2. A member here started a thread about it, check it out here: Dark frames on K-S2

Do we have a count of confirmed reports on this site? The linked thread went sideways about one page into its history and by the last post about a month ago, the count was pegged firmly at "1".

There is another thread, but it was difficult to differentiate between a camera issue and user inexperience. The OP eventually returned the K-S2 in favor of different camera.

https://www.pentaxforums.com/forums/184-pentax-k-s1-k-s2/321538-all-my-shots-dark.html


Steve

---

Last edited by stevebrot; 08-12-2016 at 01:22 PM.

[Adam]

IIRC, we started seeing K-30/K-50 issues as the cameras reached about 1 year post-sale. The K-S2 does use a similar aperture control block design to the other two cameras, but then so did the K-r, K-x, K-m, K20D, K10D, etc. I would be pleased as punch if the K-2S and subsequent consumer-line bodies are free of this gremlin.



Do we have a count of confirmed reports on this site? The linked thread went sideways about one page into its history and by the last post about a month ago, the count was pegged firmly at "1".

There is another thread, but it was difficult to differentiate between a camera issue and user inexperience. The OP eventually returned the K-S2 in favor of different camera.

https://www.pentaxforums.com/forums/184-pentax-k-s1-k-s2/321538-all-my-shots-dark.html


Steve

According to our survey, out of 23 reported K-S2's, 2 had their shutter block fail. Both were purchased in early 2015. One was repaired under warranty.

[a5m]

IIRC, we started seeing K-30/K-50 issues as the cameras reached about 1 year post-sale. The K-S2 does use a similar aperture control block design to the other two cameras, but then so did the K-r, K-x, K-m, K20D, K10D, etc. I would be pleased as punch if the K-2S and subsequent consumer-line bodies are free of this gremlin.



Do we have a count of confirmed reports on this site? The linked thread went sideways about one page into its history and by the last post about a month ago, the count was pegged firmly at "1".

There is another thread, but it was difficult to differentiate between a camera issue and user inexperience. The OP eventually returned the K-S2 in favor of different camera.

https://www.pentaxforums.com/forums/184-pentax-k-s1-k-s2/321538-all-my-shots-dark.html


Steve

According to our survey, out of 23 reported K-S2's, 2 had their shutter block fail. Both were purchased in early 2015. One was repaired under warranty.

I remember two members that had this issue and like you said only one was a confirmed yes, I just assumed the other was the same thing.

Sorry I didn't mean to spread misinformation. When I read the thread by filmamigo I figured the K-S2 was using the same hardware as the K-30 and K-50 and was susceptible to the same issue. Maybe since it is not as popular we haven't heard about a lot of failures?

Thanks Adam for providing that info. Good to know it's only 2 reported so far. Hopefully those were just isolated incidents.

[stevebrot]

According to our survey, out of 23 reported K-S2's, 2 had their shutter block fail. Both were purchased in early 2015. One was repaired under warranty.

Cool. I am looking forward to seeing the full results.


Steve

[stevebrot]

Sorry I didn't mean to spread misinformation. When I read the thread by filmamigo I figured the K-S2 was using the same hardware as the K-30 and K-50 and was susceptible to the same issue. Maybe since it is not as popular we haven't heard about a lot of failures?

Ha! Ha! You are not alone. There have been many comments on this site regarding the aperture block controller issue that go something like "...this started with the K-30, was not fixed with the K-50, and is still with us on the K-S2...". Reading such, it is easy to assume that it is a prevalent issue with the K-S2 when in reality, there is precious little hard data. I hope it stays that way.


Steve

[W.j.christy]

According to our survey, out of 23 reported K-S2's, 2 had their shutter block fail. Both were purchased in early 2015. One was repaired under warranty.

Hopefully that number stays low preferably lower than the approx 10% its showing now. Though, that data sample is so close the lower limit of what is considered statistically accurate the results are near irrelevant (sorry if that offends but my college professor drilled it into me that 20 or more data points need to be assessed and if you only get 20 then its still not good enough. If it makes it any better i near failed statistics so take this with a grain of salt) .

This issue seems like a bit of a black eye on Pentax's part. I can see how it proliferating through several generations of mid/entry level cameras would scare off potential new pentaxians.

FWIW I had a K-30 for about 2 years and had over 6000 actuations on it without issue until I got the k-3 from my wife for my birthday (shes a good woman :-) )

[Adam]

Hopefully that number stays low preferably lower than the approx 10% its showing now. Though, that data sample is so close the lower limit of what is considered statistically accurate the results are near irrelevant (sorry if that offends but my college professor drilled it into me that 20 or more data points need to be assessed and if you only get 20 then its still not good enough. If it makes it any better i near failed statistics so take this with a grain of salt) .

This issue seems like a bit of a black eye on Pentax's part. I can see how it proliferating through several generations of mid/entry level cameras would scare off potential new pentaxians.

FWIW I had a K-30 for about 2 years and had over 6000 actuations on it without issue until I got the k-3 from my wife for my birthday (shes a good woman :-) )

It's certainly higher with the K-50/K-30/K-500, but I think that since users are more likely to respond to the survey if they were affected by the issue, the global number of failures is probably lower. Many of us use our cameras considerably more than the average person, so that could further skew the results. The survey shows an overall failure rate of nearly 30% among those cameras.

[stevebrot]

my college professor drilled it into me that 20 or more data points need to be assessed

Then there are the problems of voluntary surveys from select populations.

The survey shows an overall failure rate of nearly 30% among those cameras.

That is about what I would have projected based on activity on this site. I am curious to see what, if any, impact the issue has on the Consumer Reports brand reliability survey. It is based on a three year ownership/post-purchase window. Sony, Pentax, Nikon, and Olympus have all taken a hit in the last few years with frequency of repair/serious problems in the 7-8% range (7, 7, 8, 8 respectively) for interchangeable lens cameras in the most recent survey. That survey includes data for purchases made 2010 - 2015.


Steve

[stevebrot]

No, I don't have another camera.
Well, that's quite bad news as the camera is out of warranty.

Welcome to the Pentax Forums!

Sorry for hijacking your thread.

Were you able to confirm that the body is not actuating the aperture properly? If so, how far is your camera out of warranty? If only a month or so or if the symptoms started some time ago (closer to your warranty period), I would definitely contact Ricoh/Pentax and ask for repair under warranty. It is worth a try. Repair runs about $235 USD, if I remember right and may be cost competitive to buying a replacement body.


Steve