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11-13-2013, 04:50 AM   #16
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https://www.pentaxforums.com/forums/115-pentax-k-5/201836-k-5-p-ttl-external-...rexposure.html

https://www.pentaxforums.com/forums/115-pentax-k-5/159437-k5-anyone-had-over-...e-problem.html

RiceHigh's Pentax Blog: Pathetic TTL Flash System of the Pentax K-5! >:-(

K-5 P-TTL Exposure Issue - Photo.net Pentax Forum

It seems as if you might be better off dumping the K-5 and perhaps try a K-3?

11-13-2013, 04:51 AM   #17
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QuoteOriginally posted by RKKS08 Quote
I just realized you are using a Meike ring "flash". I myself own this LED ring light, and use it occasionally.

As it is LED, it may beam pulsating light. If so, you should try to avoid very short exposure times, as you may just randomly hit moments when the ring light is dark (not visible by the eye).

Also try elliotts suggestion. When shooting with short shutter times, the body will move the lever from aperture fully open to set value and back in a fraction of a second. If the lever moves to allow for closing the aperture, it will not force the lens to do this! The lens must follow the movement of the lever just by the force of its own built in suspension! And this action must follow the lever movement immediately without delay.
The light is not the issue though as the same exposure worked with the ring flash/light/whatever you want to call it, off. I only used it to make the colors pop a little more, it hardly had much effect on the exposure. Like I said, it was cloudy, but at noon outside with nothing above you but the sky there's plenty of light, cloudy or not. I don't know how I can check for that? I moved the lever with my finger, it didn't seem to require any force at all, it wasn't stuck or stiff, it was very easy to move. Other than that I don't know what to check for.
11-13-2013, 04:56 AM   #18
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I will as soon as the price drops a little I would like to just buy it right now but if I can save a little bit of money by waiting a little... Maybe I will endure. k-5 prices seem rather low now, how sad. hopefully I will get lucky and someone will buy it for a good price (at least I have the kit lens. I would have sold it already but it sells for close to nothing and I think having the kit lens is my only chance of someone paying anything close to decent for it.) I didn't know the k-3 was on its way though, I had no idea... that's my excuse! maybe had I known about the k-3 and the problems with k-5 I would have skipped the k-5 entirely. now i wonder if going II or IIs would have saved me any trouble, probably not. how do you know the issue is fixed in k-3? would be really bad if it hadn't. if I get a k-3 and it has the same issues as my k-5 I'll go samsung or canon out of spite. haha or maybe I'll switch to film!
11-13-2013, 05:04 AM   #19
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QuoteOriginally posted by tripodquest Quote
I will as soon as the price drops a little I would like to just buy it right now but if I can save a little bit of money by waiting a little... Maybe I will endure. k-5 prices seem rather low now, how sad. hopefully I will get lucky and someone will buy it for a good price (at least I have the kit lens. I would have sold it already but it sells for close to nothing and I think having the kit lens is my only chance of someone paying anything close to decent for it.) I didn't know the k-3 was on its way though, I had no idea... that's my excuse! maybe had I known about the k-3 and the problems with k-5 I would have skipped the k-5 entirely. now i wonder if going II or IIs would have saved me any trouble, probably not. how do you know the issue is fixed in k-3? would be really bad if it hadn't. if I get a k-3 and it has the same issues as my k-5 I'll go samsung or canon out of spite. haha or maybe I'll switch to film!
Your problems don't sound like the ones in the links, those all relate to the P-TTL flash, which you are not using. I'm using a K-5 with many manual lenses and flashes, I don't have any of the problems you are having. If you set the camera in manual mode the exposure should not change as long as the light does not change.

How about posting some example pictures with EXIF. Like a series of images of the same subject in the same lighting with the same settings. If the exposure is different between them, then something is wrong.

11-13-2013, 05:05 AM   #20
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The fact that the lever is moving easily is not telling much.
  • Set the aperture to fully closed.
  • Move the lever so the aperture is fully open.
  • Then leave the lever alone (DO NOT force it) and after approximately 1/2 sec move it again to the open position.
  • During this time the aperture must close correctly, and open again.

Last edited by RKKS08; 11-13-2013 at 05:09 AM. Reason: Info added
11-13-2013, 05:08 AM   #21
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Add to elliott's post:
As the EXIF will not show aperture, you should add this information manually so we can see it.

Last edited by RKKS08; 11-13-2013 at 05:08 AM. Reason: Typing
11-13-2013, 05:11 AM   #22
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QuoteOriginally posted by RKKS08 Quote
The fact that the lever is moving easily is not telling much.
  • Set the aperture to fully closed.
  • Move the lever so the aperture is fully open.
  • Then leave the lever alone and after approximately 1/2 sec move it again to the open position.
  • During this time the aperture must close correctly, and open again.
I tried it not only at the smallest aperture (f/16) but also at f/11, f/8 and f/5.6. Several times. Works flawlessly, I could open it all day long and it would snap right back to the correct aperture time after time. Unfortunately I don't think that's where the problem lies. I meant to write something about something else I tried, but I forgot what. I still have no idea what the problem is.
11-13-2013, 05:15 AM   #23
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QuoteOriginally posted by elliott Quote
How about posting some example pictures with EXIF. Like a series of images of the same subject in the same lighting with the same settings. If the exposure is different between them, then something is wrong.
The exposure differs 10 stops between the images with the same settings, I don't need to develop the raws and post the jpg's with the EXIF to tell you this.

I can do it a lot easier: I got a perfectly exposed picture (almost perfectly, slightly underexposed) outside in daylight at noon, in overcast, under uniformly light gray (but not dark) sky, with these settings:
shutter speed: 1/15
ISO: 400


Aperture doesn't even matter at this point. The smallest aperture the lens has is f/16. It's pretty clear something is horribly wrong.

11-13-2013, 05:20 AM   #24
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Posting pics with EXIF still helps troubleshooting. Post one of the series with constant settings but different exposures.
11-13-2013, 05:24 AM   #25
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QuoteOriginally posted by VisualDarkness Quote
Posting pics with EXIF still helps troubleshooting. Post one of the series with constant settings but different exposures.
Also tell us how it is lit.
11-13-2013, 05:26 AM   #26
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A slightly bent aperture actuator (on the lens side) could cause such random problems. They may not occur when using the lens fully open.
11-13-2013, 05:32 AM   #27
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QuoteOriginally posted by VisualDarkness Quote
Posting pics with EXIF still helps troubleshooting. Post one of the series with constant settings but different exposures.
QuoteOriginally posted by elliott Quote
Also tell us how it is lit.
I don't upload the pictures from my camera every day or even every other day so I don't like the idea of having to do that every time I have a problem. It would help me if you could tell me what you are looking for in the EXIFs. Is it something I can see in-camera? (probably not?) The lighting doesn't mean anything since before the problem came up, I took two pictures, one with the flash in the 5th dimension on the planet Fluffluvian (just so it's clear it wasn't in the picture in any sense of the word), and one with the flash on as a light/fill light/whatever. The exposures and settings in both pictures are the same, and all the flash did was make the colors look better and add a tiny bit more exposure to the leaf, that's all. The only way the lighting was the issue is if the action of putting something metallic in contact with the hotshoe plate in the camera causes the camera to reduce the exposure by 10 stops.
QuoteOriginally posted by RKKS08 Quote
A slightly bent aperture actuator (on the lens side) could cause such random problems. They may not occur when using the lens fully open.
How will I check for that?
11-13-2013, 05:45 AM   #28
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QuoteOriginally posted by RKKS08 Quote
A slightly bent aperture actuator (on the lens side) could cause such random problems. They may not occur when using the lens fully open.
Okay, now I found something. When the lens is out of the camera, the aperture is closed to whatever aperture I set it to (f/5.6 in my test.) When I put it in the camera (even when the camera is off) it opens wide open. When I press the shutter, it closes down to f/5.6, takes the picture and immediately opens WO again.

I also found out the k-mount isn't native, it's just very well made on top of the petri mount. There are some contacts and a lever (might be shortened or might not be) on different sides of the lens. You can barely see them peek out the openings in the k-mount. They're clearly not there for Pentax and probably not even functional. The lever that stands there alone that you can see through a hole in the base of the k-mount might be an original aperture lever? I don't know what it is but i tried moving it manually. It moves a couple of mm but doesn't seem to affect the aperture. Any idea what it might be? it looks like a miniature version of the aperture lever. one more thing (don't know if relevant or not) i'm using the latest (i think) firmware, i upgraded a few weeks ago, it's 1.15.
11-13-2013, 05:48 AM   #29
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QuoteOriginally posted by tripodquest Quote
How will I check for that?
I wouldn't know, as you can't see what's happening once the lens is mounted.

But I would try to repeatedly use the DOF feature, and in between un-mount and re-mount the lens.
A difference of up to 10 steps should be visible in the viewfinder, too.

Also this error would not show with another lens (the kit lens).

I am frequently browsing this forum for reported issues on the technical side. During the last years, there have been tons of descriptions very similar to yours. I have not made a statistic, but I feel the number of cases when the problems were caused by the lens (or body/lens coupling) exceeded the in-camera causes by far.
11-13-2013, 05:53 AM   #30
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QuoteOriginally posted by tripodquest Quote
I don't upload the pictures from my camera every day or even every other day so I don't like the idea of having to do that every time I have a problem. It would help me if you could tell me what you are looking for in the EXIFs. Is it something I can see in-camera? (probably not?) The lighting doesn't mean anything since before the problem came up, I took two pictures, one with the flash in the 5th dimension on the planet Fluffluvian (just so it's clear it wasn't in the picture in any sense of the word), and one with the flash on as a light/fill light/whatever. The exposures and settings in both pictures are the same, and all the flash did was make the colors look better and add a tiny bit more exposure to the leaf, that's all. The only way the lighting was the issue is if the action of putting something metallic in contact with the hotshoe plate in the camera causes the camera to reduce the exposure by 10 stops.
I just want to see the images, I want to see the inconsistencies and have some information to back it up. It is starting to sound like you aren't having exposure inconsistencies with the camera, though it is hard to pick out relevant information in your posts without some images to back up your words.

QuoteOriginally posted by tripodquest Quote
How will I check for that?
If you did the test with the DOF preview lever, like I mentioned earlier, it should rule this out. I just asked for a yes or no to "does the viewfinder get darker and brighter as it should". You seemed happy with the results from this test, though I have no idea what the relevance of the meter was, so I just left it alone.

Also, if the camera is able to open the aperture, then you have a native K mount lens. The other lever you see recessed into the mount is for communicating aperture ring position to film cameras for the meter, it is not used on a DSLR. Pictures of this lens would help too, of course.
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