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03-03-2016, 09:11 PM - 1 Like   #1
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Dark exposure problems on K-30 or K-50? Read me first!

Hello everyone,

Occasionally people create new threads about their K-30 or K-50 taking dark exposures. In the interest of reducing the amount of new threads regarding the matter, I have decided to create a step-by step tutorial on the matter, albeit without any images so hope people are good with written instruction. There does tend to be an issue with some (not all) K-30 and K-50 cameras, where they take dark frames, and will require professional service either by warranty or out of warranty paid repair. This issue is known as aperture block failure. While the issue does seem to be more of a WHEN rather than an IF situation, not all dark exposure problems are caused by this issue, so no need to get prematurely paranoid about it. The goal of this tutorial is not to unnecessarily upset anyone, or discourage purchases of K-30/K-50 units (my aperture block failed in my K-50, and while I find it sad I do still use the K-50 in a limited capacity and definitely love the camera), the purpose of this tutorial is to help you diagnose possible aperture block failure in your camera, without the need to create a new thread about it.

What you will need:

1.) Possibly defective K-30/K-50 unit.
2.) A lens that has an aperture ring with an "A" setting. Or kit lens and some other manual lens with aperture ring.
3.) A few moments of your time.

As you can see, there isn't a lot required for this test, and it only takes a few minutes to perform. For the test, you will want to be in an area with adequate lighting, after all... what's the point of doing this test if you're in a dark room?
We'll do 3 different routes, one for people with lenses that have focus rings with an "A" setting, one for those without who have to use 2 separate lenses, and finally one for people who do not have any lenses with aperture rings. Please bear in mind that some instances of aperture failure can be intermittent. Intermittent failure can be caused by the motor working at some times and not working others, but it WILL eventually degrade to a constant failure state over time.

For those with lenses that have the "A" setting on an aperture ring-

Step 1:

a.) Mount the lens on the camera.
b.) Set aperture ring to "A" setting.
c.) Take a picture.
d.) Set aperture ring to an aperture value that should take a properly exposed image.
e.) Take a 2nd picture.
f.) Examine both exposures.

If the image you took when the aperture ring was set to "A" is severely underexposed (dark exposure), and the image you took with the aperture ring set to a specific value is NOT underexposed, you more than likely have aperture block failure in your unit. If BOTH exposures are dark, this could indicate a more severe problem with the unit, or there may be an issue with the lens. To rule out lens issues, try again with a different lens. Should the second lens replicate both images with dark exposures, then it might be an issue with the light meter sensor, or the image sensor.

For those who do not have a lens with "A" setting on an aperture ring (such as the kit lens)-

Step 1:

a.) Mount first lens (without aperture ring) to the camera.
b.) Set camera settings to what will supposedly create a proper exposure.
c.) Take a picture.
d.) Turn off unit and swap to manual lens.
e.) Set aperture on lens with aperture ring to an appropriate aperture value.
f.) Take another picture.
g.) Examine both exposures.

As with the previous route for those with the "A" setting, we need to examine the exposures that you took with each lens. If the exposure taken with the lens that did not have an aperture ring is dark, and the exposure taken with the lens with the aperture ring is normal, you may have aperture block failure.

For those who do not have a lens with an aperture ring-

Step 1:

a.) Mount lens to camera.
b.) Set aperture setting in camera to a value where the lens iris will be fairly open upon shutter release.
c.) Look down into lens while under decent lighting, and press shutter button.
d.) Note whether iris opens up or stays narrow.

If during your testing, the aperture iris did not widen, then you more than likely have aperture block failure. You are free to try this with multiple lenses to rule out lens issues.

Step 2: (this step is for everyone from any of the above step paths)

Upon determining that aperture block failure is the most likely cause of your problem, determine whether or not it is feasible to be repaired, or if replacing the unit will be the more cost effective option. Those who are still covered under warranty should most definitely send the unit in for repair. Those out of warranty have a difficult choice ahead of them. In my case, my k-50 aperture block failed outside of warranty. To have it repaired would have cost almost as much as a brand new in box body. I eventually relegated the k-50 to alternate/crippled usage, and purchased a K-3II as my new primary body. Not all people decide to opt for the solution I ultimately took. Several do spend the money to have the unit repaired. The choice is completely up to you.


This concludes my very brief tutorial on testing for aperture block failure in the K-30/K-50. I hope you checked here first before starting a new thread on the subject, and that you found the information here useful. If enough people consider the tutorial to be helpful, please suggest that this become a sticky topic, so that it doesn't become lost in the ever-revolving shuffle of forum topics.


Last edited by Auzzie-Phoenix; 03-04-2016 at 04:56 AM.
03-03-2016, 10:23 PM   #2
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It might be noted that the controller issue may also present as failure of the lens to stop down and may also affect mirror function (the same electronic and mechanical components operate both aperture and mirror). The problems tend to be intermittent in nature when first noticed and get progressively worse. The issue does not appear to be related to heavy usage, but may be related to age with most of the reported cases on this site being on cameras outside the one-year warranty period.


Steve
03-03-2016, 10:31 PM   #3
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Thanks for the write-up. But there is a possible source of confusion with the title. It could be construed as an article about Dark Frame Subtraction problems rather than an Aperture Control Block failure. Perhaps it could be better re-titled?
03-04-2016, 12:44 AM   #4
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QuoteOriginally posted by jbinpg Quote
Thanks for the write-up. But there is a possible source of confusion with the title. It could be construed as an article about Dark Frame Subtraction problems rather than an Aperture Control Block failure. Perhaps it could be better re-titled?
That's what I thought this thread was about

03-04-2016, 12:55 AM   #5
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QuoteOriginally posted by jbinpg Quote
But there is a possible source of confusion with the title.
My thoughts as well.


Steve
03-04-2016, 04:58 AM   #6
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Dark frame subtraction is not a function of the camera itself, and is related to stacking. If the thread were about that, it would have been in the software/processing, or general photography subforums. I have however, changed the title to read dark exposure.
03-04-2016, 07:46 AM   #7
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QuoteOriginally posted by Auzzie-Phoenix Quote
Dark frame subtraction is not a function of the camera itself
But it is. That's what long-exposure NR does.
03-04-2016, 01:22 PM   #8
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After reading this I'm glad I got an extended 3 year warranty where the shop takes care of the shipping.

03-24-2016, 08:17 AM   #9
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QuoteOriginally posted by Auzzie-Phoenix Quote
Hello everyone,

Occasionally people create new threads about their K-30 or K-50 taking dark exposures. In the interest of reducing the amount of new threads regarding the matter, I have decided to create a step-by step tutorial on the matter, albeit without any images so hope people are good with written instruction. There does tend to be an issue with some (not all) K-30 and K-50 cameras, where they take dark frames, and will require professional service either by warranty or out of warranty paid repair. This issue is known as aperture block failure. While the issue does seem to be more of a WHEN rather than an IF situation, not all dark exposure problems are caused by this issue, so no need to get prematurely paranoid about it. The goal of this tutorial is not to unnecessarily upset anyone, or discourage purchases of K-30/K-50 units (my aperture block failed in my K-50, and while I find it sad I do still use the K-50 in a limited capacity and definitely love the camera), the purpose of this tutorial is to help you diagnose possible aperture block failure in your camera, without the need to create a new thread about it.

What you will need:

1.) Possibly defective K-30/K-50 unit.
2.) A lens that has an aperture ring with an "A" setting. Or kit lens and some other manual lens with aperture ring.
3.) A few moments of your time.

As you can see, there isn't a lot required for this test, and it only takes a few minutes to perform. For the test, you will want to be in an area with adequate lighting, after all... what's the point of doing this test if you're in a dark room?
We'll do 3 different routes, one for people with lenses that have focus rings with an "A" setting, one for those without who have to use 2 separate lenses, and finally one for people who do not have any lenses with aperture rings. Please bear in mind that some instances of aperture failure can be intermittent. Intermittent failure can be caused by the motor working at some times and not working others, but it WILL eventually degrade to a constant failure state over time.

For those with lenses that have the "A" setting on an aperture ring-

Step 1:

a.) Mount the lens on the camera.
b.) Set aperture ring to "A" setting.
c.) Take a picture.
d.) Set aperture ring to an aperture value that should take a properly exposed image.
e.) Take a 2nd picture.
f.) Examine both exposures.

If the image you took when the aperture ring was set to "A" is severely underexposed (dark exposure), and the image you took with the aperture ring set to a specific value is NOT underexposed, you more than likely have aperture block failure in your unit. If BOTH exposures are dark, this could indicate a more severe problem with the unit, or there may be an issue with the lens. To rule out lens issues, try again with a different lens. Should the second lens replicate both images with dark exposures, then it might be an issue with the light meter sensor, or the image sensor.

For those who do not have a lens with "A" setting on an aperture ring (such as the kit lens)-

Step 1:

a.) Mount first lens (without aperture ring) to the camera.
b.) Set camera settings to what will supposedly create a proper exposure.
c.) Take a picture.
d.) Turn off unit and swap to manual lens.
e.) Set aperture on lens with aperture ring to an appropriate aperture value.
f.) Take another picture.
g.) Examine both exposures.

As with the previous route for those with the "A" setting, we need to examine the exposures that you took with each lens. If the exposure taken with the lens that did not have an aperture ring is dark, and the exposure taken with the lens with the aperture ring is normal, you may have aperture block failure.

For those who do not have a lens with an aperture ring-

Step 1:

a.) Mount lens to camera.
b.) Set aperture setting in camera to a value where the lens iris will be fairly open upon shutter release.
c.) Look down into lens while under decent lighting, and press shutter button.
d.) Note whether iris opens up or stays narrow.

If during your testing, the aperture iris did not widen, then you more than likely have aperture block failure. You are free to try this with multiple lenses to rule out lens issues.

Step 2: (this step is for everyone from any of the above step paths)

Upon determining that aperture block failure is the most likely cause of your problem, determine whether or not it is feasible to be repaired, or if replacing the unit will be the more cost effective option. Those who are still covered under warranty should most definitely send the unit in for repair. Those out of warranty have a difficult choice ahead of them. In my case, my k-50 aperture block failed outside of warranty. To have it repaired would have cost almost as much as a brand new in box body. I eventually relegated the k-50 to alternate/crippled usage, and purchased a K-3II as my new primary body. Not all people decide to opt for the solution I ultimately took. Several do spend the money to have the unit repaired. The choice is completely up to you.


This concludes my very brief tutorial on testing for aperture block failure in the K-30/K-50. I hope you checked here first before starting a new thread on the subject, and that you found the information here useful. If enough people consider the tutorial to be helpful, please suggest that this become a sticky topic, so that it doesn't become lost in the ever-revolving shuffle of forum topics.
There is another option you can take, which is to get a couple of vintage manual lenses and start using them in manual or P modes. I did so.
Another way to use your camera, more limited though, is using it in Light View mode on a tripod, that way the camera measures light with the aperture fully closed, it will shoot at a very slow speed but at least you get a sharp picture if your subject is still.
04-18-2016, 06:42 PM   #10
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Can we add to this a tip to ensure the viewfinder is covered during the test? Or at least that the camera is in live preview mode? I've mistakenly taken a photo with a bright light behind me that messed up the exposure control and wondered why things looked so dark.
04-18-2016, 07:55 PM   #11
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QuoteOriginally posted by JoseFF Quote
which is to get a couple of vintage manual lenses and start using them in manual
As I have said in two different threads about the failure of my K-30. This doesn't fix mine. I was using an all manual lens with no A setting working in manual mode, when the camera went down.
04-19-2016, 12:12 AM   #12
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QuoteOriginally posted by photolady95 Quote
As I have said in two different threads about the failure of my K-30. This doesn't fix mine. I was using an all manual lens with no A setting working in manual mode, when the camera went down.
Hmm... if you're still getting dark exposures on a manual aperture lens, then you have more problems than just a dead aperture mechanism. It may very well be your light sensor, image sensor, or several problems working together to emulate the aperture failure. At this point, it would probably be best to replace the camera with a used model from the for sale threads, or just buy a new body, since they're sub $300 new.
04-19-2016, 12:17 AM   #13
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QuoteOriginally posted by Auzzie-Phoenix Quote
Hmm... if you're still getting dark exposures on a manual aperture lens, then you have more problems than just a dead aperture mechanism. It may very well be your light sensor, image sensor, or several problems working together to emulate the aperture failure. At this point, it would probably be best to replace the camera with a used model from the for sale threads, or just buy a new body, since they're sub $300 new.
I did replace it. I bought a new K-50. However, I'm sending it in next month to get fixed.
04-19-2016, 08:10 PM   #14
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QuoteOriginally posted by photolady95 Quote
I did replace it. I bought a new K-50. However, I'm sending it in next month to get fixed.
Please do update us on the listed cause of failure when you get the paperwork back with the repaired camera. It might prove helpful for others for future diagnosis.
04-19-2016, 11:59 PM   #15
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Will try to remember that. But mine wasn't really giving dark exposures. It just quit working. No view screen, nothing, just dark. I tried new batteries, removing battery to resetting the camera it just wouldn't do anything no matter what I tried.
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