No need to mount the lens. If you toggle the aperture lever does the iris open? Smoothly? If not, the lens is at fault. Also check the lever to see if it has been bent or anything. It can be physically bent past the point of catching on the aperture lever the camera has built in. If the lever seems fine then its possible you might not be turning it enough, but I'm kind of assuming you have mounted it correctly.
On Thu, Jun 4, 2015 at 6:46 PM, Eric Featherstone <[email protected]> wrote: > On 4 June 2015 at 23:35, Eric Weir <[email protected]> wrote: >> Picked up my 16-45/4 from KEH today, put it on the camera, and I’m totally >> baffled. When I look through the viewfinder it’s very dark, almost black. >> With the lens wide open I can barely make out objects in the field of view >> only when pointed directly at a strong light source. And I can’t actuate the >> shutter. Replacing the 16-45 with a 35/2.4 I have absolutely no problem. >> >> I feel really stupid, but i have no idea what’s going on. Any clues? > > 1) Is it mounted properly? Turned all the way on the mount as far as it will > go. > 2) Simply faulty? > > They are, I think, the only two possibilities. > > The default for a Pentax lens (i.e. when it's off the camera) is for > the aperture to close down to the smallest setting. As you mount the > lens on the camera the little metal lever (the "stop-down" coupler) > engages with the mount and opens the aperture fully. If the lens isn't > rotated all the way when mounting then the aperture won't be fully > opened up. You can see this happening if you take the lens cap off > before mounting. See how the two lenses compare in that regard. > > -- > Eric > > -- > PDML Pentax-Discuss Mail List > [email protected] > http://pdml.net/mailman/listinfo/pdml_pdml.net > to UNSUBSCRIBE from the PDML, please visit the link directly above and follow > the directions. -- PDML Pentax-Discuss Mail List [email protected] http://pdml.net/mailman/listinfo/pdml_pdml.net to UNSUBSCRIBE from the PDML, please visit the link directly above and follow the directions.
