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01-21-2010, 07:02 AM   #1
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Green Button Stop-Down Metering Acting Differently

On my K10D when I use the Green Button with an M lens for stop-down metering, I can hear the aperture close and the shutter speed updated.

However on my K-x, not only does the aperture close, but the mirror flips up and down while the shutter is opened and closed. Had me quite surprised because that wasn't what I was expecting. Why does the K-x need to open the shutter for metering?

01-21-2010, 07:27 AM   #2
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Are you sure you have it set to Optical and not Digital Preview?
01-21-2010, 03:05 PM   #3
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Even in optical preview, the Kx does that. No one seems to know why. I'm guessing it is somehow connected to the fact that the K-m on which the K-x was based lacked optical preview at all, and the only way they could figure out to implement it without a redesign of the body was to couple it to the regular shutter firing sequence.

Last edited by Marc Sabatella; 01-22-2010 at 01:37 PM.
01-22-2010, 01:54 AM   #4
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But for metering the mirror should be down.
Or is it measuring only after the mirror is down again?

01-22-2010, 03:08 AM   #5
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As a slight aside, how does the Kx (or any camera with live view) meter when in live view mode ? As the previous poster noted, surely the mirror needs to be down to meter ?
01-22-2010, 01:40 PM   #6
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QuoteOriginally posted by blende8 Quote
But for metering the mirror should be down.
Not just metering - the optical preview wouldn't work at all if the mirror were up! The weird thing is, when you engage the preview, the mirrors stays down in its normal position - just as it does on all other cameras that provide optical preview - but when you *release* the preview, the mirror suddenly flips up and back down quickly, just as if you were taking a picture.

No idea about liveview, though. Presumably either the mirror is somehow able to still redirect light to the regular meter while flipped up, or else there is a separate meter used for liveview.

Last edited by Marc Sabatella; 08-10-2010 at 07:16 PM.
01-25-2010, 01:05 PM   #7
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I am seeing the same behavior in green button on K-x in M mode with manual lenses. The mirror flips up and down seem to happen before the stop-down of blades closing down to aperture setting. I need to play with it more to be sure. I certainly don't know the reason why that is needed in metering. It is strange and added extra noise in metering. Instead of a single noise of blades closing down, you hear the extra with the mirror flipping.

Hin
08-03-2010, 08:25 PM   #8
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Did anyone ever figure out why this is or if there is a way around it? I have a friend who recently got a K-x, and I was trying to show him how to use a M50/1.7 lens on his camera. I was quite annoyed by the loud extra mirror slap when using the green button! I would love to have a workaround for him so he wouldn't be afraid to pursue any of those nice M or K lenses out there.

Makes me happy to have a K-7...which is basically silent compared to K-x.

cheers.

08-07-2010, 10:37 AM   #9
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You can use the Av button next to the Green button on K-x to initiate stop down metering. I use this method (I am new to using M lens as well) and I dont see the mirror action with the Av button. I will give a shot to the Green button to confirm your observation.

Thx,
ertan.
08-07-2010, 12:20 PM   #10
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Well, from my tests, I can see that Av and green button has the same effect (mirror action in both cases).

On the other hand, I have the mirror effect only with metal-mount PK lenses... With my small m42 lenses (too small to shorten the electronic contacts of the camera), Av and green buttons do not even trigger the aperture lever!!! So it's totally silent, shutter speed is updated, but nothing else moves...

Maybe you could try to isolate the lens mount?
08-08-2010, 03:54 AM   #11
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QuoteOriginally posted by dlacouture Quote
Well, from my tests, I can see that Av and green button has the same effect (mirror action in both cases).

On the other hand, I have the mirror effect only with metal-mount PK lenses... With my small m42 lenses (too small to shorten the electronic contacts of the camera), Av and green buttons do not even trigger the aperture lever!!! So it's totally silent, shutter speed is updated, but nothing else moves...

Maybe you could try to isolate the lens mount?
HHmmm - I've just tried metering with an M50 lens in my K-x, and I am not convinced the mirror is coming down. Maybe it is, but the action is less loud and creates less vibration than the 'clonk' that accompanies taking a shot properly.

Certainly not a problem, whatever is going on...
08-09-2010, 01:01 AM   #12
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QuoteOriginally posted by timo Quote
HHmmm - I've just tried metering with an M50 lens in my K-x, and I am not convinced the mirror is coming down. Maybe it is, but the action is less loud and creates less vibration than the 'clonk' that accompanies taking a shot properly.
Surely because there is no shutter action in this case (which is rather loud in fact).
08-10-2010, 08:19 AM   #13
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QuoteOriginally posted by dlacouture Quote
Well, from my tests, I can see that Av and green button has the same effect (mirror action in both cases).

On the other hand, I have the mirror effect only with metal-mount PK lenses... With my small m42 lenses (too small to shorten the electronic contacts of the camera), Av and green buttons do not even trigger the aperture lever!!! So it's totally silent, shutter speed is updated, but nothing else moves...

Maybe you could try to isolate the lens mount?

I have noticed the same with my M42's. The ST 55/1.8 and S-M-C 28/3.5 are smaller and don't cover the contacts and as a result pressing either button results in a silent shutter speed update in M mode. The ST 50/1.4 is larger and I get the Mirror flip noise everyone is experiencing. I don't one any K or M series lenses.
08-10-2010, 03:06 PM   #14
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QuoteOriginally posted by arpaagent Quote
Did anyone ever figure out why this is or if there is a way around it? I have a friend who recently got a K-x, and I was trying to show him how to use a M50/1.7 lens on his camera. I was quite annoyed by the loud extra mirror slap when using the green button! I would love to have a workaround for him so he wouldn't be afraid to pursue any of those nice M or K lenses out there.

Makes me happy to have a K-7...which is basically silent compared to K-x.

cheers.
I just tried to place a clear piece of tape over the contacts and my ST 50/1.4 was quiet when pressing the green button. You may want to try it and see if it works for you
08-10-2010, 03:44 PM   #15
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Problem is that it will work for wide open apertures only (as it won't stop the lens down anymore), so you would better use Av mode in this case anyway...

I guess there is no easy solution to this "mirror up" problem...
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