Sears 135mm f2.8 K-mount -- using aperture ring?

bikerboy_ro · 11-25-2008, 01:20 PM

Hi, I have recently got my hands on one of the Sears 135mm f2.8.
Now, the lens is in mint condition, looks and feels very good.
My question would be, for the ones that have this lens, what should I do to be able to use the aperture ring? I mean it works when off camera, my K200D is set to allow the use of the ring, but I see no difference, it stays wide open all the time when on the body!
Any thought would be appreciated.
Thanks!

stevebrot · 11-25-2008, 01:46 PM

Assuming yours is a non-A lens, you need to be in M mode in order for the lens auto aperture to work (stop down at exposure time). Any other mode should default to AV with the aperture stuck wide open.

Steve

bikerboy_ro · 11-25-2008, 02:41 PM

Yes, you are so right! I am working in M mode with this lens but I didn't realize I would not see the effects of stopping down in the viewfinder but only in the final picture... doh :ugh:
Thank you for enlightening me

Marc Sabatella · 11-25-2008, 04:30 PM

Originally posted by bikerboy_ro

Yes, you are so right! I am working in M mode with this lens but I didn't realize I would not see the effects of stopping down in the viewfinder but only in the final picture...

Same as with modern lenses - aperture stays open to make focusing easyier, stops down only when the shot is taken. Only difference is that with auto lenses, the camera knows the aperture and can meter full time. With manual lenses, the camera doesn't know the aperture, so it can only meter while temporarily stopping down - either by hitting the Green button (which stops down only momentarily but sets an appropriate shutter speed for you) or by doing an optical DOF preview (which stops down for as long as hold the lever in position, and meters the whole time too).

madbar · 11-27-2008, 09:01 AM

Hi,

I just received a similar lens (RMC TOKINA 135mm f2.8). It works well as you explained above, but when I take a picture, it takes two seconds before the shutter is actionned. Which spoils the sport use I had in mind for this lens.

Is this normal? Can it be fixed?

Thanks!

Alain

Pentax K20D
DA 18-250 | FA 50mm f1.4 | Sigma 10-20mm | Tokina 135mm f2.8

bikerboy_ro · 11-27-2008, 02:20 PM

Maybe you are using the Mirror Up function by accident?

You can check that in the shooting menu, by pressing Fn and choosing the Drive Mode

11-25-2008, 01:20 PM	#1
bikerboy_ro Inactive Account Join Date: Nov 2008 Location: Bucharest Posts: 12	Sears 135mm f2.8 K-mount -- using aperture ring? Hi, I have recently got my hands on one of the Sears 135mm f2.8. Now, the lens is in mint condition, looks and feels very good. My question would be, for the ones that have this lens, what should I do to be able to use the aperture ring? I mean it works when off camera, my K200D is set to allow the use of the ring, but I see no difference, it stays wide open all the time when on the body! Any thought would be appreciated. Thanks!

11-27-2008, 09:01 AM	#5
madbar New Member Join Date: Nov 2008 Posts: 5	slow to shoot Hi, I just received a similar lens (RMC TOKINA 135mm f2.8). It works well as you explained above, but when I take a picture, it takes two seconds before the shutter is actionned. Which spoils the sport use I had in mind for this lens. Is this normal? Can it be fixed? Thanks! Alain Pentax K20D DA 18-250 \| FA 50mm f1.4 \| Sigma 10-20mm \| Tokina 135mm f2.8 Last edited by madbar; 11-27-2008 at 09:15 AM.

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11-25-2008, 01:46 PM	#2
stevebrot Otis Memorial Pentaxian Join Date: Mar 2007 Location: Vancouver (USA) Photos: Gallery \| Albums Posts: 42,007	Assuming yours is a non-A lens, you need to be in M mode in order for the lens auto aperture to work (stop down at exposure time). Any other mode should default to AV with the aperture stuck wide open. Steve

11-25-2008, 02:41 PM	#3
bikerboy_ro Inactive Account Join Date: Nov 2008 Location: Bucharest Posts: 12 Original Poster	Yes, you are so right! I am working in M mode with this lens but I didn't realize I would not see the effects of stopping down in the viewfinder but only in the final picture... doh :ugh: Thank you for enlightening me

11-25-2008, 04:30 PM	#4
Marc Sabatella Veteran Member Join Date: Sep 2006 Location: Denver, CO Photos: Gallery Posts: 10,685	Originally posted by bikerboy_ro Yes, you are so right! I am working in M mode with this lens but I didn't realize I would not see the effects of stopping down in the viewfinder but only in the final picture... Same as with modern lenses - aperture stays open to make focusing easyier, stops down only when the shot is taken. Only difference is that with auto lenses, the camera knows the aperture and can meter full time. With manual lenses, the camera doesn't know the aperture, so it can only meter while temporarily stopping down - either by hitting the Green button (which stops down only momentarily but sets an appropriate shutter speed for you) or by doing an optical DOF preview (which stops down for as long as hold the lever in position, and meters the whole time too).

11-27-2008, 02:20 PM	#6
bikerboy_ro Inactive Account Join Date: Nov 2008 Location: Bucharest Posts: 12 Original Poster	Maybe you are using the Mirror Up function by accident? You can check that in the shooting menu, by pressing Fn and choosing the Drive Mode