Minolta MD 40-80 F2.8

Distefano · Joined: 26 Mar 2024 Posts: 1 Location: the Netherlands

Hello,

Does anyone have experience with the Minolta MD 40-80 F2.8?

This weekend I was able to obtain one in good condition for a decent price.

I will see if I can test this in the next few weeks.

I just had a first sneak peak and the focussing is different with the focus ring on the side of the lens. Nevertheless it is not that different at all. I will shoot some pictures. Since this will be my first time uploading them in this forum would you have any pointers what to particularly pay attention to? My Camera is a Sony A7M4 so not super high resolution, hopefully 33MP is sufficient to test this lens.

Regards,

Stefan

RokkorDoctor · Joined: 27 Nov 2021 Posts: 1271 Location: Kent, UK

Welcome Distefano.

I have one of these myself. Optically it is quite reasonable, especially considering it is an early f/2.8 zoom, which was fast for the time. It is not of the same optical quality as its "successor" the MD 35-70 f/3.5, but very usable.

I have always found it a little awkward to use; especially the macro mode.

The main quality issue I have with this lens is the focus mechanism, which has a little "play". That may just be my copy but the mechanism of this lens is theoretically quite prone to that with the zoom groups sliding on rails and the focus being a one-sided cam-follower in cam-slot affair. Even very small wear on the nylon focus cam-follower bushing and the tiniest slack in the guide rails setup (required to prevent binding) can cause a noticeable play and hysteresis on the focusing.

For those familiar with the field of metrology, the construction of this lens' focus and zoom mechanism violates Abbe's principle. Although from a different field of origin, this principle also guides the (in)stability of the focus setup here.

No doubt this was one of the reasons Minolta stepped away from this zoom construction, and reverted to using the standard zoom mechanisms that have 2 or three circumferentially located cam-followers for each zoom group, which does conform to Abbe's principal assuming precision engineering of the cam-slots. The very high component count for this zoom mechanism would be the other reason they discontinued this mechanism.

A "unique" consequence of this zoom construction is that unlike almost every other zoom out there, this one employs unit focusing.

If you are interested in the inner workings of this lens, there is this teardown:

https://www.lensrentals.com/blog/2017/09/the-minolta-40-80mm-f2-8-gearbox-zoom-the-clockwork-lens/