[samski_1]

I recently obtained a couple of manual Leica R lenses in k mount which I am very happy with except for one issue:
it seems impossible to accurately focus them at apertures of f8 or smaller as the viewfinder gets increasingly darker as you close the diaphragm. I have to focus at a wider aperture and then readjust the aperture ring before taking the shot which is a real bugger when using the camera without a tripod. I have used other manual lenses without this happening, is this normal with Leica lenses? I am using them with a K-7.

[feilb]

What other manual lenses? The only lenses this won't be a problem on are auto aperture lenses like the pentax a series or "preset" lenses like the Jupiter 9 (which have one aperture ring to set the aperture and a second to quickly switch between wide open and the aperture "preset" with the other).

[taurus9]

This is the normal behaviour for adapted lenses, including the Leica R's. It is stop-down metering only in this case since the aperture lever in the R mount lens is not controlled in Pentax cameras. The only cameras that accept R-mount lenses without having to perform stop-down metering are ... the Leica R series cameras.

If you're talking about manual lenses in general, Pentax M and K mount lenses do not require stop-down metering because the green button does that for you.

If possible, focus first, stop down to meter and then shoot. It is a part of the workflow when one uses adapted lenses, but I guess one plus is permanent depth of field preview...

[samski_1]

What other manual lenses? The only lenses this won't be a problem on are auto aperture lenses like the pentax a series or "preset" lenses like the Jupiter 9 (which have one aperture ring to set the aperture and a second to quickly switch between wide open and the aperture "preset" with the other).

The problem does not happen with pentax K and M series manual lenses. I have used 28mm and 55mm K lenses and 50mm and 85mm M lenses with no issues.

This is the normal behaviour for adapted lenses, including the Leica R's. It is stop-down metering only in this case since the aperture lever in the R mount lens is not controlled in Pentax cameras. The only cameras that accept R-mount lenses without having to perform stop-down metering are ... the Leica R series cameras.

If you're talking about manual lenses in general, Pentax M and K mount lenses do not require stop-down metering because the green button does that for you.

If possible, focus first, stop down to meter and then shoot. It is a part of the workflow when one uses adapted lenses, but I guess one plus is permanent depth of field preview...

Thanks taurus9, that clears it up. Reputation point added