[Tracy68]

Back in 2015 RedSky posted this: "My new k50 showed very dark pictures when taken thru the viewfinder, and then a second later repeat the exact same picture, not even moving the camera,nor more making any adjustment, and view it thru live view and the picture is fine. Auto, scene, or manual, does not matter, dark thru viewfinder, good thru live view. Let camera rest and no change, let it rest some more, and all is fine. Tested again today and fine at first, then back to dark viewfinder pictures. Sent to repairs today, as I had passed my return window." See link below

I am experiencing the exact issue. In fact, "dark" is an understatement - the pictures are black. Any information would be appreciated - is this common? Is it fixable?

Honestly, I'm really disappointed with the K-50, overall (except that I purchased the red one!).

Thank you for any help.

Read more at: K-50 Live View vs Viewfinder (Viewfinder photos Under exposed) - PentaxForums.com

[revelstoked]

My guess would be that your aperature control has failed or is failing. This is a common problem with k50s. Mine failed about 1 year in. If your camera is out of warranty or you do not want to pay for repairs, a simple workaround is to shoot with manual aperature control as long as your lenses have an aperature ring.

[The Squirrel Mafia]

Dark exposure problems on K-30 or K-50? Discussion Thread - PentaxForums.com
^ Take a look a this thread.

my fix of the K-30 aperture problem without disassembly: Pentax SLR Talk Forum: Digital Photography Review
^ Before you attempt any type of fix, try is temporary fix. It might work for a while.

K-50 / K-500 Aperture Solenoid fix (DIY with pics) - PentaxForums.com
^ This is a permanent fix.

In a nut shell. If your camera ends up having the aperture motor failure, which I'm about 99% sure that's the issue, the only permanent fix is replacing the faulty "green" solenoid with a "white" one. This requires disassembly of the camera & a bit of soldering. It's not hard, but it does take some time & patience. Everything is extremely small. I've done it twice already on my black & red K-50 bodies which were heavily used. One failed at about 25,000 photos & the other at about 32,000 photos. Some people have had their cameras fail at about 400 photos or even less. Sucks.

There are other fixing methods like sanding down the "green" solenoid & junk like that, but more than likely the camera will either fail again and/or develop other issues in the long run. Even if you send it back in, Ricoh is only going to replace the faulty "green" solenoid with another faulty "green" solenoid which will extend the life for about another 2 years, but if it's for free, why not?

[reh321]

Back in 2015 RedSky posted this: "My new k50 showed very dark pictures when taken thru the viewfinder, and then a second later repeat the exact same picture, not even moving the camera,nor more making any adjustment, and view it thru live view and the picture is fine. Auto, scene, or manual, does not matter, dark thru viewfinder, good thru live view. Let camera rest and no change, let it rest some more, and all is fine. Tested again today and fine at first, then back to dark viewfinder pictures. Sent to repairs today, as I had passed my return window." See link below

I am experiencing the exact issue. In fact, "dark" is an understatement - the pictures are black. Any information would be appreciated - is this common? Is it fixable?

Honestly, I'm really disappointed with the K-50, overall (except that I purchased the red one!).

Thank you for any help.

Read more at: K-50 Live View vs Viewfinder (Viewfinder photos Under exposed) - PentaxForums.com

Before I jumped to any conclusions, I would do some testing.

The gold standard for diagnosing aperture block failure is to put the camera in M mode (auto ISO off, aperture ring not being used) with aperture set wide open and shutter speed at something slow (e.g. 1-2 seconds). Release the shutter while observing the aperture opening through the front of the lens.* Anything other than the aperture remaining wide open is indication of a problem with the controller. If the problem has been intermittent, it may help to do the test after a period of non-use. Even one failure is significant.

* This method was instrumental in diagnosing the initial wave of aperture block failures on the K-30 and narrowing the cause to a fault in a mechanical component rather than electronics.

Then I would examine one of the "dark" images in a photo editor, such as PhotoShop or gimp. Photos resulting from the aperture control issue are dark, not truly black; the histogram is pushed to the left, but it

does still have a curve.

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Last edited by reh321; 03-25-2019 at 05:31 PM. Reason: re-insert image

[stevebrot]

Any information would be appreciated - is this common? Is it fixable?

Welcome to the Pentax Forums!

It is likely that your camera has an aperture control failure where the lens aperture is stopping down all the way rather than to the opening set by the meter. The common cause is due to a defective solenoid in something called the Diaphragm Control Block (aka Aperture Control Block) in the camera body.

This sort of problem is not uncommon in K-30 and K-50 models and is fixable. I believe the cost through the Pentax-authorized repair facility (Precision Camera Repair in Connecticut) is under $200*. Claims that Precision will replace the defective piece with a similar defective part are unfounded, at least in regards to those I know who have had the repair done and are happy to report that the repair is still good, four years or more later.

Alternatively, there are various other shops that advertise a fix for about $100 or less, though most are unwilling to said how it is done. Current consensus is that used parts from other model cameras are being used since the so-called "white made-in-Japan" solenoids are reportedly no longer available. If all the above sounds rumor-based and rather sketchy, that is because information on Internet forums is often so. I write that in full respect for those (particularly a tenacious group in Germany) who have worked this issue extensively through many false leads and much speculation to end up with a plausible cause and remedy.

Given that you are not that fond of the camera, the most reasonable path might be to take the money that might have been applied towards a repair and use it to purchase something that is more to your liking.


Steve

(...went through the repair process with Precision in 2015 and am happy with the result...)

* The figure I remember for the repair through Precision was $149, but don't hold me to it.

[reh321]

Read more at: K-50 Live View vs Viewfinder (Viewfinder photos Under exposed) - PentaxForums.com

Did you read the last two posts in this thread?
@RedSky reported that same problem, and sent camera in for repair; 'repair' was usual fix to the aperture control system, and it did no good.

My new k50 showed very dark pictures when taken thru the viewfinder, and then a second later repeat the exact same picture, not even moving the camera,nor more making any adjustment, and view it thru live view and the picture is fine.

Repairs replaced a Diaphramg control block, their spelling, and it is no better.

[reh321]

I am experiencing the exact issue. In fact, "dark" is an understatement - the pictures are black. Any information would be appreciated - is this common? Is it fixable?

Another thought - when you take two photos, and the photo taken using LiveView is OK but the photo taken using viewfinder is black, are the aperture / shutter-speed settings the same?

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Last edited by reh321; 03-25-2019 at 02:45 PM. Reason: spell out LiveView

[Maxman1947]

Excuse my ignorance, but if the diaphragm control is not working and stopping the aperture down instead of opening it to the proper value, then won't the pictures be dark in both viewfinder and live view? If the pictures are exposed properly in live view then the aperture must be working correctly. When using the viewfinder and you press the shutter the mirror goes up, the diaphragm goes to the proper setting and the shutter fires. In live view the mirror is already up and when you press the shutter release the diaphragm goes to the proper setting and the shutter closes and then fires at the proper speed and then opens again for live view. If the pictures are completely black in viewfinder mode, I think it is because the mirror is not going up before the shutter fires. If that is the case then while looking through the viewfinder and pressing the shutter release the viewfinder will not black out during shutter activation. If I am wrong, please correct me, I'm not a expert on camera operation.

[reh321]

Excuse my ignorance, but if the diaphragm control is not working and stopping the aperture down instead of opening it to the proper value, then won't the pictures be dark in both viewfinder and live view? If the pictures are exposed properly in live view then the aperture must be working correctly. When using the viewfinder and you press the shutter the mirror goes up, the diaphragm goes to the proper setting and the shutter fires. In live view the mirror is already up and when you press the shutter release the diaphragm goes to the proper setting and the shutter closes and then fires at the proper speed and then opens again for live view. If the pictures are completely black in viewfinder mode, I think it is because the mirror is not going up before the shutter fires. If that is the case then while looking through the viewfinder and pressing the shutter release the viewfinder will not black out during shutter activation. If I am wrong, please correct me, I'm not a expert on camera operation.

I was thinking the same things, which is why I kept thinking new thoughts.

[Tracy68]

My guess would be that your aperature control has failed or is failing. This is a common problem with k50s. Mine failed about 1 year in. If your camera is out of warranty or you do not want to pay for repairs, a simple workaround is to shoot with manual aperature control as long as your lenses have an aperature ring.

Well, that does work, as long as I open it up quite a bit. I'll keep this in mind. Thank you.

---------- Post added 03-26-19 at 10:19 AM ----------

Before I jumped to any conclusions, I would do some testing.

Then I would examine one of the "dark" images in a photo editor, such as PhotoShop or gimp. Photos resulting from the aperture control issue are dark, not truly black; the histogram is pushed to the left, but it does still have a curve.

Thanks - yes, when I use a photo editor, I can increase the exposure and see an image - so not black, but dark.

I've done some testing as mentioned in the thread. Using M and AV modes I can see the aperture close and open and I get an image. In auto mode dark image.

---------- Post added 03-26-19 at 10:22 AM ----------

Another thought - when you take two photos, and the photo taken using LiveView is OK but the photo taken using viewfinder is black, are the aperture / shutter-speed settings the same?

Yes. I just switch viewing mode, nothing else.

---------- Post added 03-26-19 at 10:25 AM ----------

I was thinking the same things, which is why I kept thinking new thoughts.

But the pictures aren't really blacked out, there's a very (very) dim image, so the mirror would be working. (I exaggerated due to my frustration!). Thanks for the input.

---------- Post added 03-26-19 at 10:42 AM ----------

my fix of the K-30 aperture problem without disassembly: Pentax SLR Talk Forum: Digital Photography Review
^ Before you attempt any type of fix, try is temporary fix. It might work for a while.

Tried this with no change. Although I see the utility of programming the Raw/fx button this way now! Thanks.

[reh321]

But the pictures aren't really blacked out, there's a very (very) dim image, so the mirror would be working. (I exaggerated due to my frustration!). Thanks for the input.

OK, so take two photos of the same scene "at the same time", one with LiveView and one with viewfinder.
Assuming only the LV one is "good", are aperture and shutter speed in the EXIF the same?

[Rondec]

Basically, when the camera doesn't move the aperture lever, it shoots stopped all the way down all of the time -- f22 or whatever is the smallest aperture your lens will shoot at. But the camera is exposing as though you are shooting at f5.6 or whatever you have the camera set to.

You can shoot with lenses that have an aperture ring and control the aperture that way.

If you are handy with tools and a soldering iron, you can fix it yourself.

You can send it in to have it repaired. Precision is the authorized place. I used this place: Pentax Camera Repair - Aperture Control Repair They charge 100 dollars and did a good job with my daughter's KS-1.

I guess you have to decide how much money you want to sink into an older camera, but it is probably worth fixing.

[reh321]

Basically, when the camera doesn't move the aperture lever, it shoots stopped all the way down all of the time -- f22 or whatever is the smallest aperture your lens will shoot at. But the camera is exposing as though you are shooting at f5.6 or whatever you have the camera set to.

You can shoot with lenses that have an aperture ring and control the aperture that way.

If you are handy with tools and a soldering iron, you can fix it yourself.

You can send it in to have it repaired. Precision is the authorized place. I used this place: Pentax Camera Repair - Aperture Control Repair They charge 100 dollars and did a good job with my daughter's KS-1.

I guess you have to decide how much money you want to sink into an older camera, but it is probably worth fixing.

Why so certain this is the aperture control issue?
Why would aperture control work with LV but not with viewfinder?

[Rondec]

Why so certain this is the aperture control issue?
Why would aperture control work with LV but not with viewfinder?

I don't know. It just seems most likely based on what we know about these cameras. I suppose you would want to try it with different lenses and in particular setting the aperture manually using an aperture ring to see what is going on for sure.

[reh321]

I don't know. It just seems most likely based on what we know about these cameras. I suppose you would want to try it with different lenses and in particular setting the aperture manually using an aperture ring to see what is going on for sure.

OK ... I wanted to be sure you weren't seeing something I was missing.


OP began by referencing experience of @RedSky, whose last post on the subject began

...Repairs replaced a Diaphramg control block, their spelling, and it is no better.

then said

the parameters change when switching to live view that suggests that it's not the diaphragm block at fault but just a discrepancy between metering through the viewfinder and in live view ..... I believe it's due to the camera metering off the sensor rather than the prism.

My advice to the OP remains to take two photos consecutively at the same place and roughly the same time - the first using LV and the second using the viewfinder. If they visibly differ in brightness, then compare EXIF data.


added: After reviewing unfortunate experience of @RedSky; I would add the following suggestions:

1. Do not use 'Auto' mode.

2. Do not use 'auto' ISO

3. When using viewfinder, make sure camera is pressed against your eye