Optical Review Blog No. 54 – Minolta Maxxum AF 20mm 1:2.8

At the end of my 24mm f/2.8 review I asked: Do I now need to find and invest in the 20mm? Well if you’re reading this review, the answer was yes. I enjoy working with wide-angle lenses, and while I do have the lovely 17-35/2.8-4 D ultra-wide zoom, there’s something special about an ultra-wide prime lens. I started looking at getting this particular lens after I finished my 24/2.8 review for the A-Mount. The desire to add one to my A-Mount kit only increased after picking up the 14mm f/2.8D for my Nikon kit. I was always concerned about the cost of these lenses; usually, when you go ultra-wide and fast, the price goes up. But these early-generation A-Mount lenses aren’t that bad. I eventually got my hands on one and immediately enjoyed the focal length and image quality out of the 20mm f/2.8. It also looks really good on the front of my Maxxum 9.

Lens Specifications
Make: Minolta
Model: Maxxum AF 20mm 1:2.8
Focal Length: 20mm
Focal Range: ∞ – 0.25m
Aperture: f/2.8 – f/22, 7 (Straight) Blades
Structure: 10 Elements in 9 Groups

Build Quality
There is nothing wrong with the build quality of this lens, as it is a first-generation A-Mount lens. Most lenses are constructed from metal, especially the areas that take the most stress, such as the lens mount and the filter ring. Additionally, the exterior body of the lens is made of plastic, but it certainly doesn’t feel that way. Despite being wide and fast, the lens is surprisingly compact, following the same form and fit as the other prime lenses in the early generation A-Mount lenses. Although it does feature a significant front element with a 72mm filter ring. The lens also has a bayonet ring for a lens hood. The lens itself is far lighter than you expect, doesn’t throw off the balance of the camera, and fits well on my Maxxum 9 and Dynax 600si. Given the age of the lens, the autofocus is a little slow, but nothing too serious, and I have never run into a problem with accuracy. The one concern is that the focusing ring is even thinner than other era lenses, but again, the A-Mount is an autofocus-first system. Overall, the build quality of the lens is excellent, and despite getting that dreaded white marks on the rubber sections, there are no serious concerns with the quality of the construction.

Image Quality
It should come as no surprise that the one thing that this lens has is a lot of distortion; without any aspherical element, you’re getting a lot of barrel distortion when you’re in close and even a bit when you’re a little further away. I also did not attempt any corrections in post-production. I don’t know if there’s a preset with Adobe Lightroom/Photoshop to help. But the distortion is exacerbated by having to position my camera so close to ‘fill the frame’ with the test chart. When you’re shooting the lens wide-open at f/2.8, you’ll also see some heavy vignetting at your corners, but what surprises me is that there’s little to no sharpness fall-off. The lens doesn’t perform well in the wide-open sharpness category, with the images appearing soft on the edges. Once you’re past f/5.6, the vignetting has all but cleared up, and the sharpness has improved. The aperture sweet spot starts at around f/8. That’s where I see the sharpness improving. The out-of-focus rendering on the lens isn’t anything special; the edges are smoothed out, but you’re not buying an ultra-wide angle lens for anything interesting in your out-of-focus areas because by f/8 you’re almost getting the whole frame in focus, which does by f/11. Minolta did release a lens hood (flower petal styled), but I don’t have that for my lens, so I do notice that there is a tendency to flare with off-axis light sources, but if you’re careful, it doesn’t cause too many problems.

Applications
Like any ultra-wide angle lens, the 20mm has a limited application, mostly aimed at architecture and landscape work. And that is precisely what I use mine for. It is my first choice when working in urban areas when I am limited in space or want to capture the big picture. Plus, being an f/2.8 lens, you can do a lot of indoor and lowlight work without sacrificing too much depth of field, and the 20mm also helps keep the camera shaking when using the camera handheld at slow shutter speeds. This is the lens I reach for when taking my Minoltas out in urban spaces or even hikes, especially architectural tours. It also helps when working in historic downtowns that may not have as much space between buildings, and I want to show off the entire building. Of course, there are things this lens won’t work well for, and that’s working with people unless you’re talking large groups when you need to get everyone in one shot when you don’t have a lot of space. But as a portrait lens, unless you’re into that weird distortion close-up, I wouldn’t go with the 20mm. While you can mount/adapt this lens onto Sony digital cameras, I don’t recommend using this lens in the digital sphere; a video review below shows that the lens doesn’t play well with digital sensors.

The Low Down
This is a lens that you want rather than need to be honest and as someone who loves working with wide-angle and ultra-wide angle lenses it is certainly one that has been on my want list. One of the more surprising things about this lens is that despite being an ultra-wide lens and being fast it is surprisingly affordable. You can find good copies of the lens between 130-200$, of course there are copies that are ‘complete’ with boxes, caps, hood, and cases that are well over 200$ but if you’re only looking for the lens then you don’t have to drop that much cash. I’m glad I got this lens, it makes life a lot easier than having to pull out the 17-35mm, while a nice lens, I never got a long with that lens like I do with my Nikkor 14-24mm. While I don’t take this lens out much, it is nice to have it in the kit all the same.

Further Reading
Don’t just take my view on the Maxxum 20/2.8, check out these other reviews.
Ken Rockwell – Sony Minolta 20mm f/2.8 Review
Eric Woods Photography – Minolta Maxxum/Sony A Mount 20mm f/2.8
Dyxum – Minolta AF 20mm F2.8 A-mount lens reviews
Fervent Astronomy – Even I don’t know why I tested this lens for astrophotography – Minolta AF 20mm F2.8 Review