[Cory Tarilton]

I've done a bit of research but can't seem to find out if there is a way to enable a manual aperture selection on either version of this lens for use with older film bodies. Right now I am looking forward to the new FF, and my kit is a Pentax Superprogram and K-3 with a 12-24, 24-70, and 70-200 which all work for APS-C, FF, and 35mm, except the 70-200 is the only lens that will not work in the 35mm format since it defaults to a closed aperture at F22.

There is no aperture ring on the lens, but is there a way to decouple its spring or something like that to allow manual selection?

[boriscleto]

The SuperProgram can set the aperture of the lens. It is an A series body, it was called the Super A everywhere but the US.

[Cory Tarilton]

My superprogram will not meter in a selected aperture for that lens, nor will it allow manual aperture input via the camera. It defaults to F22 and does not allow any other selection. When in A-mode, it also only meters at F22. It will, however, meter and allow selection for my other two lenses

[rawr]

Which Sigma 70-200 are you interested in? There are four versions of this lens listed in the PF database.

FWIW, the one-page 'manual' for the HSM II version says this (in relation to Nikon, but it may be relevant to Pentax too):

"NIKON AF TYPE CAMERAS
This lens functions in the same way as a G Type auto-focus Nikon lens (without an aperture ring). Functions may be restricted depending on the lens/camera combination."

but also:

SETTING THE EXPOSURE MODE
The Sigma lens functions automatically once attached to the camera. Please refer to the
camera instruction book.

[boriscleto]

My superprogram will not meter in a selected aperture for that lens, nor will it allow manual aperture input via the camera. It defaults to F22 and does not allow any other selection. When in A-mode, it also only meters at F22. It will, however, meter and allow selection for my other two lenses

Does it work in Shutter Priority? Set the shutter dial to M.

[stevebrot]

My superprogram will not meter in a selected aperture for that lens, nor will it allow manual aperture input via the camera. It defaults to F22 and does not allow any other selection. When in A-mode, it also only meters at F22. It will, however, meter and allow selection for my other two lenses

I don't know what metering has to do with any of this. From your description, it appears that the aperture mechanism in your 70-200 lens is not functioning correctly (remains at f/22).

Your Super Program should support any lens K-mount lens that has an aperture ring and/or "A" contacts on the mount. If a lens lacks an aperture ring, functionality is limited to program and shutter priority modes only. Film cameras having a dial for aperture control on the camera support will support both Av and M modes with lenses lacking an aperture ring.

Since two other lenses (both lacking aperture rings) work to your expectations on the Super Program, it is safe to assume that the 70-200 has a problem. Are you able to manually work the aperture actuator with the lens off the camera? Is the lens wide open when mounted to the camera? (It should be.) Is there any indication of damage to the aperture actuator lever?


Steve

(...owns Super Program Camera...has used it with lenses lacking aperture rings in both program and shutter priority modes...)

[Adam]

I've done a bit of research but can't seem to find out if there is a way to enable a manual aperture selection on either version of this lens for use with older film bodies. Right now I am looking forward to the new FF, and my kit is a Pentax Superprogram and K-3 with a 12-24, 24-70, and 70-200 which all work for APS-C, FF, and 35mm, except the 70-200 is the only lens that will not work in the 35mm format since it defaults to a closed aperture at F22.

There is no aperture ring on the lens, but is there a way to decouple its spring or something like that to allow manual selection?

Since there's no aperture ring, you can't use the lens with any legacy camera that does not support either P or Tv (shutter priority) mode, i.e. the M and K series bodies. There's no way around this I'm afraid.

Adam
PentaxForums.com Webmaster (Site Usage Guide | Site Help | My Photography)



PentaxForums.com server and development costs are user-supported. You can help cover these costs by donating or purchasing one of our Pentax eBooks. Or, buy your photo gear from our affiliates, Adorama, B&H Photo, KEH, or Topaz Labs, and get FREE Marketplace access - click here to see how! Trusted Pentax retailers:

[Cory Tarilton]

Ahh bummer, I thought there might be some way to easily modify it to remove/weaken the aperture lever actuation spring. That seems to be the only real difference between it and my other lenses that work on the body.