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11-19-2014, 07:51 AM   #1
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my K-3 cannot close aperture, help!

Hi,

my K-3 cannot close aperture for all the lenses I have. e.g. for F2.8 lens, if I step down to F4, it will stuck at F2.8 (wide open), so the photo is overexposed as expected. any idea?

Thanks,
Bill.

11-19-2014, 07:55 AM   #2
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If it's an M lens, you have to set the green button to close down the aperture.
11-19-2014, 07:58 AM   #3
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It's not M lens, the lenses I tried are D FA 100mm F2.8, Sigma 70-200mm F2.8 EX DG Macro HSM II, and Tamron 28-75mm F2.8.
11-19-2014, 08:16 AM   #4
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QuoteOriginally posted by fa8362 Quote
If it's an M lens, you have to set the green button to close down the aperture.
That's only to get a meter reading. If you set a M lens to f8, it stops down to f8 when the picture is taken.

11-19-2014, 08:19 AM   #5
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Which mode are you using ? Have you used AV mode to see if the aperture is working correctly ? If no help and all lenses are all wide open I would try to clean the contacts to see if it helps.
11-19-2014, 08:25 AM   #6
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all meter readings are correct, that's why the photo taken at F4, F8, etc. (with F2.8 lens) is overexposed (due to the aperture stuck wide open). I just contacted Ricoh, since my camera is still under warrenty, I can send in for a check up. But I will do that only I don't have any choice (I will try anything suggested here first). Thx.
11-19-2014, 08:26 AM   #7
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QuoteOriginally posted by Wolfeye Quote
That's only to get a meter reading. If you set a M lens to f8, it stops down to f8 when the picture is taken.
No, "M" lenses stay wide open during exposure unless you use the green button. "A" lenses stop down, but "M" lenses require green button use. I have two "M" lenses and if I don't use the green button, the aperture opens fully during exposure, regardless of aperture setting.

Last edited by fa8362; 11-19-2014 at 08:32 AM.
11-19-2014, 08:31 AM   #8
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QuoteOriginally posted by Wolfeye Quote
That's only to get a meter reading. If you set a M lens to f8, it stops down to f8 when the picture is taken.

Well he seems to have a D FA lens so it would be able to use the auto aperture within the camera when changing in camera. If a manual lens and change the Aperture manually in lens, the green button would be used at that point to stop down but that would not be the case in this instance.

11-19-2014, 08:43 AM   #9
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QuoteOriginally posted by fa8362 Quote
No, "M" lenses stay wide open during exposure unless you use the green button. "A" lenses stop down, but "M" lenses require green button use. I have two "M" lenses and if I don't use the green button, the aperture opens fully during exposure, regardless of aperture setting.
Well, with my M lenses, I use Manual exposure mode. Let's say I set the shutter speed to 1/60th. Then I set my aperture to f8 and press the green button. It resets the shutter speed after stopping down, say, to 1/15th. Then I press the shutter button. The exposure is correct, so the lens must have stopped down at some point. Are you saying the green button locks the aperture down?

I do realize that in AV mode, the aperture does not stop down regardless of what the aperture ring is set to. I only use M mode.

Last edited by Wolfeye; 11-19-2014 at 08:50 AM.
11-19-2014, 08:45 AM   #10
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QuoteOriginally posted by ULong Quote
It's not M lens, the lenses I tried are D FA 100mm F2.8, Sigma 70-200mm F2.8 EX DG Macro HSM II, and Tamron 28-75mm F2.8.
Since all the lenses you use are AF lenses, you have to set the lens to the "A" setting so that the camera can recognize the lens and stop down accordingly. When you mount the lens to the camera, can you check that you are setting it to "A"?
11-19-2014, 09:07 AM   #11
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Let me get this straight, try this:
  • With lens off camera, confirm that the actuator lever on mount consistently opens/closes the diaphragm
  • Mount lens to camera
  • Aperture ring on "A"
  • Aperture value shows on top LCD?
  • Set aperture using e-dial to f/22 in M mode
  • While looking down front of lens toggle the optical DOF preview. Confirm that the lens stops down.
  • Set shutter to 3 seconds, look down front of lens, and confirm that lens stops down fully without hesitation and opens fully at the end of the 3 seconds
The sequence is intended to test for A-contact recognition and the mechanical aperture actuation. If the fourth bullet point fails, clean the contacts with a microfiber cloth and try again. If either of the last two bullets fails, you have a problem that requires service.


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11-19-2014, 09:13 AM   #12
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Thanks Steve, I will try that when I get home. Thank you all for your advise!
11-20-2014, 06:57 AM   #13
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I did verify, M lenses do indeed stop down the aperture in M mode, no need to press the green button.
11-20-2014, 07:16 AM   #14
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I've been using K-x for a couple of years, nothing has happened. I guess I'm out of luck this time. I tried all the steps Steve provided, but didn't work. Since it's still under warranty, I'll go ahead and send it to Ricoh for repair. Thanks again guys for all your help!
11-20-2014, 04:07 PM   #15
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QuoteOriginally posted by Wolfeye Quote
That's only to get a meter reading. If you set a M lens to f8, it stops down to f8 when the picture is taken.
You have to switch Mode to M for that to happen, otherwise it will remain open!

---------- Post added 20-11-14 at 16:13 ----------

QuoteOriginally posted by Wolfeye Quote
I did verify, M lenses do indeed stop down the aperture in M mode, no need to press the green button.
The green button only closes the aperture to the selected F nr so that there is an exposure reading. it's a stopped down metering!
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