01 Nov Minolta 40-80 F2.8 (The Gearbox Zoom)
I recently discovered the existence of the Minolta 40-80 F2.8 lense while searching for repair manuals for my XK. I was quite intrigued by this quirky lense and it’s yet another Minolta innovation. I found one locally that was way below the asking price of ebay and I could not resist picking it up. The condition was ok, a few paint chips and a hair line scratch on the front element (the bottom right corner in the above image).
The 40-80 F2.8 was released in 1976 and was one of the first fast standard zoom lenses. I’ve read that Canon also introduced a 35-70 F2.8 zoom in the same year but I couldn’t find any information on it. The “Gearbox Zoom”, as it is called by the small group of people who know about this lense, gets its name from the, you guessed it, gearbox on the side of the lense. It is actually a very interesting design that allowed Minolta to produce a very high image quality F2.8 zoom using optics technology from the 1970s. Unlike traditional zoom lenses, the glass elements aren’t aligned in a helicoid format, instead the glass elements are placed on a track that is controlled by the gearbox tumour. This allowed the optical elements to more more freely to better correct distortion. The result is the first “standard” F2.8 zoom with image quality that allegedly hasn’t been surpassed until the arrival of modern day zooms.
Bonus: A video of the 40-80 in action. I love how the entire zoom crank shifts as you focus and zoom. What magic lies within that black box!?
The design of the lense ultimately failed, which is why we don’t see gearboxes on all our zoom lenses. I have read that it was due to its mechanical complexity which I cannot comment on but I also think the control interface (zoom crank) was just too strange. The quirky zoom and focusing isn’t particularly hard to use but when every other lense on the market uses the standard format, your lense better be exceptional. And I guess that’s the story of the Minolta 40-80 F2.8: quirky but not quite exceptional enough.
My observations so far:
When I first held it, I was surprised by the size and weight. I expected the lense to be much bigger despite seeming images of it in the past. I guess the gearbox just changed my expectations. The lense also felt surprisingly light in hand, again I think the unorthadox design skewed my expectations. All the exposed parts are made of metal except the crank (more on that later). The lense weighs around 1.3 pounds or 0.59kg.
I haven’t done any extensive testing yet (I would need a Sony a7 series for that) but the results I’ve seen look promising. There is a flickr album of someone who has shot with the lense on a NEX3 but since it is a crop sensored camera, I don’t think it accurately shows what the lense can do. The bokeh rendering looks nice, as does the sharpness in the central areas. I plan to shoot this lense with my XK and report the results so look for that post in the near future.
In terms of build quality, the lense is quite solid but I think it has some flaws. The zoom crank on the side is made of very cheap feeling plastic and it is the most vulnerable part of the lense. When I received it, the crank was fairly loose but it was an easy fix, all you have to do is peel the centre leather and tighten the two screws. Having the crank made out of metal would have increased the perceived build quality of the lense significantly. The rest of the lense is the standard build of the Rokkor lenses at the time. On my copy, the focusing wheel turns very smoothly but the zooming mechanism isn’t as smooth. It might have to do with aging lubricant or it could be by design.
Overall, this is definitely a must have for Minolta lense collectors!
PS I took the two photos in this post. The first photo was lit with two flashes; one snooted, one with a softbox, and a reflector. The second shot was just one flash with softbox. I did some post processing for contrast and cloning out dust but I left all the scratches and dings on the lense and body on purpose.