Minolta Rokkor Meter Coupling Tab

I have been shooting an X-370 with the 58/1.4 and 50/1.4. Great pics, good exposures, quite pleased. I then acquired an MD 100/2.5 which was fantastic as well. Figured to round out the set with a wide. Found the MD 35/2.8 for a steal at a thrift shop.

It seemed like it was overexposing as I shot the first roll (X370 is aperture priority, mind you). Sure enough, the pics not shot in manual seem about +2.

Then, upon further inspection, I see that the "meter coupling tab" is in different positions on my 1.4's vs the slower lenses. The 1.4 tab is lined up with f8, whereas the slower lenses are lined up with f16. I didn't really notice if the 100 seemed like it was overexposing or not, but its tab is at 16 too. Maybe it was, and the scans autocorrected.

From web searching, I understand, this tab placement is intentional because of the way the really fast lenses meter wide open.

Seems like the placement would actually cause underexposure on the slower lenses as the 50/1.4 at f8 and the 35/2.8 at f16 would look the same to the camera body.

Any insight is appreciated. Thanks.

If it is a factory installed tab and your having exposures issues, chances are that it is not the tab. Minolta lenses of different focal lengths and focal ratios have the MD tabs located in different places. Your MD tab is only used for Program or shutter priority modes, in aperture priority it is doing nothing. Is your lens foggged or have any haze? That would throw off exposure. Take a closer look at that lens.

Consider treating yourself to a XD-11 which is a much better body and buy it from a camera dealer rather than a thrift store.

***. Check your aperture blades. Oily or sluggish blades will cause the wrong exposure regardless of what your meter reads. I've found quite a few "dogs" at thrift stores. There are some very YouTube videos showing you how to open and repair Minolta Rokkor lenses. These lenses are 40 years old.

Best of luck.

Just to clarify here, Matthew is referring to the MC full-aperture metering tab. The MD tab is an additional tab that engages a switch at about the 10 o'clock position (facing the camera) on cameras that support MD. The MD tab and switch were introduced with the XD-11 (US, XD-7 or XD elsewhere) to support Shutter priority automation, and later Program control with the X-700.

Matthew, I agree with Rick's analysis. The tabs on your lenses were positioned where they are to provide correct exposure information during full aperture metering. Different full-aperture values for different lenses will have tabs positioned in different places. It's easy enough to evaluate whether you've got different metered values with different lenses. Choose an evenly, well lit, but blank subject area (the sky, a wall, green grass, etc.) and observe the exposure reading you get with each lens. They should all agree. If they do, but you've determined that indeed your exposure is off with a given lens, then, as Rick mentions, look to the lens's iris especially to make sure it's opening and closing properly. That is the most likely culprit. Another possibility, but one I feel is much less likely, is that the levers on the rear of the lens are not engaging properly with the tabs inside the camera mount. I'm not as familiar with Minolta as I am with other systems, but I have had times with my Canons where a breechlock lens wasn't mounted properly and the result was the tabs and levers were not properly engaged. The solution in this case is simple: dismount and carefully remount the lens. Do Minoltas ever suffer from this problem? I dunno, but I doubt it.