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10-04-2018, 09:58 AM   #1
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K-1 aperture block??

Does anyone heard of K-1 aperture block issues? I took my K1 for shooting after a 2 weeks of rest. My first click with the 28-105 is completely black.
I shot a pic indoors at 1/80, ISO3200. From 2nd pics onward, it is absolutely fine. I observed the same sometime back, but didn't mind it much. But, this time, I am very concerned. Does anyone had similar issue with their K1s? Please help!

10-04-2018, 10:52 AM   #2
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I've had the shutter and mirror lose synchronization before. The camera makes a really funky sound - not the usual *schnick-clap*. That gives a dark frame. It's a very, very rare occurrence though.
10-04-2018, 10:59 AM   #3
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The K-1 uses a completely different mechanism from the ones prone to failure on the K-30/50. Not impossible but less likely with the K-1. As the saying goes "One swallow does not a summer make". If it becomes frequent then consider having the camera serviced.
10-04-2018, 01:16 PM - 1 Like   #4
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Was it truly and completely black or was there some ghosting of light or the image?

1. Aperture block problem images aren't black, they have a ghost of the actual image with very deep DoF (because the aperture was incorrectly narrowed to the smallest setting).

2. Mirror problems tend to leave a faint ghost of light at the upper-edge of the image because some light gets past the lower edge of the mirror.

3. Only some shutter and sensor problems may be totally black.

P.S. Check the EXIF on that image: it may show that something (or someone used a very strange exposure setting.

10-04-2018, 02:44 PM   #5
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I've had both completely black images and partially blocked images from the rare moment when the mirror and shutter lost synchronization. The part of the image not blocked in the partially blocked image was just fine.
10-04-2018, 10:30 PM   #6
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QuoteOriginally posted by 6BQ5 Quote
I've had both completely black images and partially blocked images from the rare moment when the mirror and shutter lost synchronization.
I have completely black image, as attached below in first link. 2nd link is something which I got a pic immediately after with same settings.


QuoteOriginally posted by photoptimist Quote
Was it truly and completely black or was there some ghosting of light or the image?
One strange observation is, after the first click, I see the LCD and it is pretty dark and camera is in writing mode, thought it is taking time. But, after 2-3 seconds, I heard the mirror flap (or coming back to original position), but the shutter is set at 1/80 @f4. So immediately I took another pic and it fine as shown in 2nd pic. Both pictures are jpeg and just out of camera.

https://drive.google.com/open?id=1xrS4k8ZY_lh_q1JUV0z8LYDYFJRBTisp

https://drive.google.com/open?id=1f9sZQioCSmRoER1p_udeJlfSUXtPtqDV
10-05-2018, 03:08 AM   #7
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I've not heard of any aperture block problems with either the K-1 or K-1 II. As Photoptomist says, with aperture block failure, the camera still takes a photo, it is just that the lens is set at the smallest aperture (say f22), while the camera thinks that it is shooting at f4 or f5.6. This produces really dark images, but if you brighten them in photoshop or wherever, you can still see an image there. This sounds different.

You might try a different memory card too...
10-05-2018, 05:18 AM   #8
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Once again the diaphragm control block (Pentax's term for the assembly for moving the iris) between the K-1 and K-50/30 differ completely in design. That is not to say that it cannot fail in a similar fashion. DSLRs are very complicated devices and it is remarkable they are as reliable as they are. The K-3 (not sure about the K-5) uses the same design mechanism and as of yet no one on PF has reported failure. Yours would be the first K-1/k-3 on Pentax Forums to show a control block failure.

To understand and diagnose the control block failure see this thread:
Dark exposure problems on K-30 or K-50? Read me first! - PentaxForums.com

10-20-2018, 11:11 AM   #9
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My K-1 developed the same problem. It started occusionally producing a completly dark first picture after the camera was in sleep mode or turned off. Now it does it for every first shot after some time in sleep mode or being turned off.

It happens on two different batteries and two different SD-cards so I think I can rule this out.
It seems like the shutter somehow does not open in time for the first shot, after that every picture is ok. Its just damn annoying because in some instances at the second shot the moment I want to capture is gone...

I wonder if thats an electronic problem.

I bought my K-1 very early (probably first batches) and took alot of pictures since then.[COLOR="Silver"]

---------- Post added 10-20-18 at 11:16 AM ----------


There is also another guy at the K-1 Facebook group who seems to have the same issues.

Last edited by Snakeisthestuff; 10-20-2018 at 11:18 AM.
10-21-2018, 05:39 AM   #10
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Hi,
Iím probably the guy having the same problem, on FB, with a black first (and now often 2nd) photo. Iíve been assuming itís the mirror not flipping up. The mirror in a full frame is significantly heavier than a crop sensor. My camera has a quieter sound and less shake when taking a black photo than a normal photo. That said, I havenít taken the lens off to see if thatís true!
I bought mine in mid-May 2018. Iíve assumed itís a later run but it could be old stock. The firmware is 1.5(.?). Iím hoping itís still under warranty (but I _love_ it so much, Iíd hate to go back to my well loved D5300, even for a day).
Have you been in contact with anyone who services Pentax?
10-21-2018, 11:03 PM   #11
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QuoteOriginally posted by JoeKrepps Quote
Hi,
Iím probably the guy having the same problem, on FB, with a black first (and now often 2nd) photo. Iíve been assuming itís the mirror not flipping up. The mirror in a full frame is significantly heavier than a crop sensor. My camera has a quieter sound and less shake when taking a black photo than a normal photo. That said, I havenít taken the lens off to see if thatís true!
I bought mine in mid-May 2018. Iíve assumed itís a later run but it could be old stock. The firmware is 1.5(.?). Iím hoping itís still under warranty (but I _love_ it so much, Iíd hate to go back to my well loved D5300, even for a day).
Have you been in contact with anyone who services Pentax?
After starting the thread and till today, I had the issue twice.. first shot black. I removed the lens from camera and mount cap fixed, kept it aside for few days. Yesterday, I took my camera out and attached Sigma 150-500 for birding and the first shot is blank. Earlier, I tried only pentax lenses, but this a sigma lens. I bought it second hand, and it looks it is an early first/second batch camera. I didn't checked with any Pentax Service guys, but if I had this issue another few times, will give it a try.
10-22-2018, 08:59 AM   #12
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One stop-gap solution to this problem might be to get in the habit of triggering the "digital preview" function on the power switch a time or two after each power-on or wake-from-sleep. In theory, that should exercise the balky mirror/shutter mechanism to increase the chance that the first time you hit the shutter, it takes the picture works as expected.
10-22-2018, 09:36 AM   #13
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hmm I was going to buy a used K-1, may be I should consider buying a new K-1 and add a 4 yr extended warranty.
10-22-2018, 10:13 AM   #14
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I have similar type issues with many of my cameras K-1, K-3 and K-5. My solution? Leave the camera in burst mode and shoot three shots for every image. It's surprising how often one stands out compared to the other two, even when I don't have some kind of random exposure failure.

Of course, on a tripod with live view, just chimp before you move.
10-22-2018, 10:23 AM   #15
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QuoteOriginally posted by JoeKrepps Quote
Hi,
Iím probably the guy having the same problem, on FB, with a black first (and now often 2nd) photo. Iíve been assuming itís the mirror not flipping up. The mirror in a full frame is significantly heavier than a crop sensor. My camera has a quieter sound and less shake when taking a black photo than a normal photo. That said, I havenít taken the lens off to see if thatís true!
I bought mine in mid-May 2018. Iíve assumed itís a later run but it could be old stock. The firmware is 1.5(.?). Iím hoping itís still under warranty (but I _love_ it so much, Iíd hate to go back to my well loved D5300, even for a day).
Have you been in contact with anyone who services Pentax?
Your camera is still under warranty and if it were me, I would send it in. As noted above, the diaphragm control block on your camera is dissimilar from that on the K-30/K-50. It also differs in the control for mirror and diaphragm being managed by separate components. If your mirror is not rising and the condition is not being detected, that is a serious fault.


Steve
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