Comparing two old manual focus 135mm lenses adapted to a modern Sony E-Mount Camera.
The Battle of the 135
One of the joys of using a mirror-less camera like my Sony A6000 is that, by using adapters, one can access a huge variety of old manual focus lenses at very reasonable prices. The 135mm focal length used to be popular in the film days, and was a common telephoto and portrait lens choice. When mounted to an APS-C camera such as the Sony A6000 this focal length is a bit on the long side at about 202 mm equivalent crop. However, there are still situations where these lenses can be useful, provided you keep the shutter speed relatively high at 1/200s or more. I got my hands on two 135mm manual focus lenses for very little money, so I was eager to see how they performed. The two lenses I tested are:
Yashica (Yashinon) 135mm f/2.8 Auto
Bushnell 135mm f/2.8
The Bushnell is a sort of "generic" brand and I believe it was sold with other brand names.
Both lenses are very well made (see Figures 1 and 2) with mostly metal construction. This also means these are heavy lenses that don't balance too well with a small mirror-less camera. However, after some use, you will develop techniques to handle them to where this won't be much of an issue. As was customary in lenses of this era, they both include built-in hoods. This is a nice feature that I wish more modern lenses had. The Bushnell is a more compact lens and I like the look of the lens better as it matches the black body of the Sony A6000. Focus is smooth in both and the aperture rings have a nice feel.
Figure 1 - The 135mm Lenses. Yashica left; Bushnell right
Figure 2 - The 135mm Lenses. Yashica left; Bushnell right
So how do these lenses perform? Let's have a look at the test results...
Testing - The Fridge Test
As usual, the "fridge test" consists of placing the lens and camera on a tripod, manual focusing on the fridge in areas of detail (papers, magnets, etc) and then shooting at various apertures to see how the lens performs. Most lenses perform better at the center of the frame than at the corners, so both cases were considered. See Figures 3 and 4 below. All photos were shot with a Sony A6000 body.
Figure 3 - Center Performance
Figure 4 - Corner Performance
I have to say that I was very pleasantly surprised by the Yashica's performance. The lens is very sharp even wide-open at f2.8 in both the center *and* the corners. It is so sharp infact that stopping it down only improves the performace marginally. A very impressive performance, even compared to a modern lens. The Bushnell on the other hand is fairly good at the center but even there the Yashica outperforms it. In the corners, there's no contest: the Yashica beats it hands-down.
The 135mm focal length is very long so the depth of field is quite shallow at wide apertures. Unfortunately the setup I used below (Figure 3) doesn't really showcase the bokeh too well (no highlights in the background). However, one can still see that the bokeh is smooth and pleasant for both lenses. One item that surprised me was the huge amount of chromatic aberration in the Bushnell when wide-open (see the blue line in the nurses' hat towards the top). The Yashica also has some CA (magenta in that case) but not nearly as bad as the Bushnell. Stopping down the lens helps a lot in both cases.
Figure 5 - Bokeh Comparison
As much as I wanted to like the Bushnell lens, since it is the more compact of the two, I have to say the Yashica is a much better lens. The Yashica 135mm f2.8 is actually a very impressively sharp lens across the frame, even by modern standards. A very good value for the $20 I paid for it. I end this article with a photo I shot with the Yashica lens (using my old NEX-5N body). This promises to be an interesting option in my lens "arsenal".
Figure 5 - Flower detail. Sony NEX-5N with Yashica (Yashinon) 135mm f/2.8
Comments, questions, suggestions? You can reach me at: contact (at sign) paulorenato (dot) com