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04-23-2019, 10:17 PM   #1
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Weird Videography Glitch, K-1 and the new 50mm f/1.4

I recorded some new videos for my YouTube channel this week and I've noticed a weird glitch with my K-1 and ONLY the new 50mm f/1.4 with the electronic shutter. Randomly, and usually after about 9 minutes of recording, the electronic shutter appears to pop open and won't close until I stop the video and adjust the aperture.

I have looked through the lens afterward to see what's happening, and the aperture is fully open. I typically shoot video for my channel at f/8, but certainly no wider than 6.3 or 5.6. I think the clip below was f/8 or f/11.

Also, the issue persists until I adjust the aperture on the camera, meaning that if I don't adjust the aperture the lens will remain wide open while, it seems, telling the camera it is at f/8 or f/11,

Has anyone else experienced anything like this?

Here is a quick clip, no audio, that shows it when it happens. My current thinking is that this is an electronic shutter glitch. The lens is great otherwise and this is inconsistent, so before I called Pentax I wanted to see if this was something anyone had heard of. As you may be able to see in the video, it is literally fine in one frame and then not fine in the next.



04-23-2019, 11:04 PM   #2
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QuoteOriginally posted by K David Quote
...and ONLY the new 50mm f/1.4 with the electronic shutter.
Is it safe to assume you intended are talking about the KAF4 electronic aperture control/actuation on the D FA* 50/1.4? If so, popping to the full open state might indicate a drop of power or a fatal error in the controller workings. (Temp? Battery?)


Steve

Last edited by stevebrot; 04-23-2019 at 11:13 PM.
04-24-2019, 01:43 AM   #3
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Although it could just be a power issue, I'd recommend reporting this to ricoh as it might be a good candidate for a firmware stability fix.

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04-24-2019, 04:57 AM   #4
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QuoteOriginally posted by stevebrot Quote
Is it safe to assume you intended are talking about the KAF4 electronic aperture control/actuation on the D FA* 50/1.4? If so, popping to the full open state might indicate a drop of power or a fatal error in the controller workings. (Temp? Battery?)
That let me think about a software timeout for the aperture command, that obviously wouldn't work for video recording.

04-24-2019, 07:32 AM   #5
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QuoteOriginally posted by biz-engineer Quote
That let me think about a software timeout for the aperture command, that obviously wouldn't work for video recording.
Would not work for long time exposures either.


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04-24-2019, 08:13 AM   #6
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QuoteOriginally posted by stevebrot Quote
about the KAF4 electronic aperture control/actuation
Thank you, yes. That's the word I needed.

QuoteOriginally posted by Adam Quote
it might be a good candidate for a firmware stability fix.
Will do and good idea. I'm hoping it's a firmware issue. That was my first thought since it doesn't happen with the 31mm or the older 100mm macro with the aperture ring. The new 50mm is my only Pentax lens without an aperture ring.

QuoteOriginally posted by stevebrot Quote
Would not work for long time exposures either.
That gives me an idea of something I need to test. I'll give this a go with a long exposure and see what happens.
04-24-2019, 09:28 AM   #7
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QuoteOriginally posted by stevebrot Quote
Would not work for long time exposures either.
Yes, this came to my mind. Then I thought the video section of the firmware may be different from the photography section of the camera firmware.... obviously, here I make an assumption.
In live view mode, the actual aperture setting used by the camera may be different from the f number programmed by the used, in order to maintain a constant frame rate and brigthness on the back display. If I set my lens aperture to f5.6 (manually), and point the camera to a darker area, I can hear the camera opening up the lens aperture to wider than f4, f2.8 etc. even if the camera still indicates that the aperture is f5.6.
04-24-2019, 09:43 AM   #8
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I sent Ricoh an e-mail with a description of the issue, a link to the video I shared in my original post, and all the details I have. If they respond, I'll let everyone know.

04-25-2019, 02:09 PM   #9
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I heard back from Ricoh. They asked what firmware I have (1.5) and then suggested that I upgrade to 1.51 (despite the 1.51 firmware apparently only having an affect on the new 11-18mm lens.) So I'll do that and we'll see what happens when I record hte next batch of videos in a week.
05-04-2019, 09:27 PM   #10
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Update:

I upgraded the firmware. It's worse. The issue happens more frequently and it's not rectifying as readily as it had been. So this seems to be an issue (I'm waiting for Ricoh to get back to me to see if I'm right) with the lens' electronic aperture. It looks like I may have made a mistake being an early adopter.
6 Days Ago   #11
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Still waiting on a response from Ricoh following the latest firmware update. Nothing and it's been eight days since I follow up, and I haven't heard anything from then since April 25. Won't lie, this is starting to make me a bit unhappy.
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QuoteOriginally posted by K David Quote
Still waiting on a response from Ricoh following the latest firmware update. Nothing and it's been eight days since I follow up, and I haven't heard anything from then since April 25. Won't lie, this is starting to make me a bit unhappy.
One week isn't much time considering that they have to have someone who is assigned to reproduce the problem in lab and look for a solution before given a suitable answer. That said, things are weird at Pentax cameras these days..
6 Days Ago   #13
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QuoteOriginally posted by biz-engineer Quote
One week isn't much time considering that they have to have someone who is assigned to reproduce the problem in lab and look for a solution before given a suitable answer.
Which is totally cool. I just would like them to say 'hey, we need to replicate this. Can you give us a couple months to see what's going on?' But being ignored makes it feel like they hope I'll just give up and live with equipment that doesn't work correctly.
5 Days Ago   #14
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QuoteOriginally posted by K David Quote
I upgraded the firmware. It's worse.
Note that you can downgrade as well. You may want to try older firmware versions. Perhaps 1.5 is a better option while you are waiting for a response from Ricoh.

Does the issue reliably occur after x minutes into a video recording?
If so, others could check whether they can reproduce the problem. It could be just an issue with your copy, even though that seems unlikely.
5 Days Ago   #15
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QuoteOriginally posted by Class A Quote
Does the issue reliably occur after x minutes into a video recording?
Actually, one thing that makes me think that it's a mechanical issue with the lens is that it's unpredictable. Sometimes the aperture pops open and then immediately shut (this is uncommon). Most of the time when it happens it opens and then doesn ot close until I change settings on the camera. This happens anywhere from 3 to 9 minutes into a video. One time, the lens held the aperture shut for 11 minutes.

So it's not reliably predictable.
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