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01-31-2008, 02:46 PM   #1
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Aperture ring on FA lenses

I am trying to understand how to use the aperture ring on FA lenses (the 43/1.9). I set the aperture ring to anything other than "A", and the camera mode to AV. The aperture size in the viewfinder reads "F--", which is understandable. Now, I set the aperture on the lens by rotating the ring. I was expecting the shutter speed to change automatically. Unfortunately this did not happen. Also, no matter what the aperture ring setting, the photo is taken with the aperture fully open. Even the DOF preview doesnt seem to close down the aperture (though it does make a nice click sound).

If I set the camera to M mode, things work as expected - I set the aperture on the ring, press the green button, and the camera closes down the aperture and figures the required shutter speed. The captured photo has the right aperture setting and shutter speed.

Am I missing something here? Is it not possible to use the AV mode with the aperture ring?

Update: Okay, I really need to learn how to use search before posting a question here. This thread basically answers the question I asked above.


Last edited by ankit; 01-31-2008 at 02:57 PM.
01-31-2008, 03:03 PM   #2
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QuoteOriginally posted by ankit Quote
I am trying to understand how to use the aperture ring on FA lenses (the 43/1.9). I set the aperture ring to anything other than "A", and the camera mode to AV. The aperture size in the viewfinder reads "F--", which is understandable. Now, I set the aperture on the lens by rotating the ring. I was expecting the shutter speed to change automatically. Unfortunately this did not happen. Also, no matter what the aperture ring setting, the photo is taken with the aperture fully open. Even the DOF preview doesnt seem to close down the aperture (though it does make a nice click sound).

If I set the camera to M mode, things work as expected - I set the aperture on the ring, press the green button, and the camera closes down the aperture and figures the required shutter speed. The captured photo has the right aperture setting and shutter speed.

Am I missing something here? Is it not possible to use the AV mode with the aperture ring?

Update: Okay, I really need to learn how to use search before posting a question here. This thread basically answers the question I asked above.

yep,

if the lens is not in "A", it no longer functions "automaticaly"

the moment you start spinning it, you must use it in Manual mode, and meter with the EL button.
02-01-2008, 01:15 AM   #3
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As far as I know:
None of the KxxxDs or *ist Ds is able to work with any lens in Av mode unless the aperture ring is in A position. You will have to shoot in M mode while using the aperture ring. I think on some pages they describe it as "crippled" K mount. Basicaly, if the ring is off A position, the camera body/ it's lens mount is unable to obtain f value in other than M mode...
02-01-2008, 01:19 AM   #4
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For more read and the technical details behind, you can read my full article about the K-mount:

K Mount Metering & Exposure Bases - A Technical Brief

QuoteOriginally posted by ankit Quote
I am trying to understand how to use the aperture ring on FA lenses (the 43/1.9). I set the aperture ring to anything other than "A", and the camera mode to AV. The aperture size in the viewfinder reads "F--", which is understandable. Now, I set the aperture on the lens by rotating the ring. I was expecting the shutter speed to change automatically. Unfortunately this did not happen. Also, no matter what the aperture ring setting, the photo is taken with the aperture fully open. Even the DOF preview doesnt seem to close down the aperture (though it does make a nice click sound).

If I set the camera to M mode, things work as expected - I set the aperture on the ring, press the green button, and the camera closes down the aperture and figures the required shutter speed. The captured photo has the right aperture setting and shutter speed.

Am I missing something here? Is it not possible to use the AV mode with the aperture ring?

Update: Okay, I really need to learn how to use search before posting a question here. This thread basically answers the question I asked above.


02-01-2008, 12:26 PM   #5
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Rice, that is excellent information! Thanks a lot.

ankit
02-01-2008, 10:59 PM   #6
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QuoteOriginally posted by ankit Quote
Rice, that is excellent information! Thanks a lot.

ankit
Oh, you're welcome! I'm glad that you like it. :-)
02-02-2008, 10:33 PM   #7
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QuoteOriginally posted by ankit Quote
Rice, that is excellent information! Thanks a lot.

ankit

There should be no occasion to take an 'A' lens off of the 'a' position with a any digital body.
You can manually set the aperture using 'on body controls' This is why the new digital family of lenses has removed the ring---it serves no purpose.
02-04-2008, 04:01 AM   #8
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Ankit, I'd recommend reading p. 210 of your K10D manual, where there's a handy table discussing the characteristics of various lens/shooting mode combinations when using an aperture-ring lens in other than the "A" position. What you described in your post was exactly what the manual said you'd get.

02-04-2008, 04:54 AM   #9
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QuoteOriginally posted by rvannatta Quote
There should be no occasion to take an 'A' lens off of the 'a' position with a any digital body.
You can manually set the aperture using 'on body controls' This is why the new digital family of lenses has removed the ring---it serves no purpose.
Not really. For *ist D and DS users who wish to force the camera to fire in TTL mode, there is a way as suggested by JensR at his page to turn away from the A to cheat the camera:-

jr-worldwi.de: Photography: Technic

Anyway, I tried his method long ago on my DS but failed. I used a latest FA* lens to try though.
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