2016
SMC Pentax 135 f2.5 - Smooth and solid
Pentax made several versions of the 135 f2.5 in the M42 mount. The best of these was the Super-Multi-Coated TAKUMAR with a 6 elements in 6 groups design (vs the single coated 5/5 Takumars). The K-mount version (reviewed here) is optically identical to that 6/6 lens. However, potential buyers should be aware that there is also a cheaper non-SMC K-mount version, which allegedly isn't as good. In other words, with the exception of the ridiculously rare and prohibitively priced Pentax-A 135 f1.8, this is as good as it gets at 135mm in the vintage Pentax world.
The SMC Pentax 135/2.5 specs:
Build Quality/Handling (Excellent/Good)
The build quality and mechanical operation of the lens are excellent. It has all-metal construction that feels very solid and well put together. The focus ring, which travels about 210° between 1.5m and ∞, is wide and very smooth and is a pleasure to use. The aperture ring is metal and has well-defined, precise clicks.
With adapter the Pentax is a bit on the long side. It also makes for a front-heavy combo on the A7s. Though it is more than a hundred grams lighter than the Canon nFD 135 f2, the difference isn't really noticeable in practical use.
Image Quality (Very good)
The Pentax is certainly capable of some very good results on modern mirrorless cameras. Let's look at sharpness wide open on the A7s first.
The SMC Pentax 135/2.5 specs:
- 6 elements in 6 groups
- Weight - 500 grams
- Length - 86 mm (112 mm with adapter; 128 mm when focused to min. distance)
- Filter size - 58 mm
- Min. focus distance - 1.5 m
- Aperture - 8 blades, f2.5 to f32 in half-stops
Build Quality/Handling (Excellent/Good)
The build quality and mechanical operation of the lens are excellent. It has all-metal construction that feels very solid and well put together. The focus ring, which travels about 210° between 1.5m and ∞, is wide and very smooth and is a pleasure to use. The aperture ring is metal and has well-defined, precise clicks.
With adapter the Pentax is a bit on the long side. It also makes for a front-heavy combo on the A7s. Though it is more than a hundred grams lighter than the Canon nFD 135 f2, the difference isn't really noticeable in practical use.
Image Quality (Very good)
The Pentax is certainly capable of some very good results on modern mirrorless cameras. Let's look at sharpness wide open on the A7s first.
Click for full resolution
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And a few shots on the a6000.
@f4 - click for full resolution
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@f8 - Click for full resolution
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100% center crops f2.5, f4, f5.6, f8
100% crops of top left corner - f2.5, f4, f5.6, f8
I would argue that wide open the lens is usuable on both cameras for subjects which are in the center of the frame. It's certainly sharp enough, especially on the 12mp A7s. However, while central resolution peaks at f5.6-f8 on the a6000, corners improve further at f8, which is the sharpest aperture on this lens. Overall, these are decent results, but nothing spectacular. Though I haven't done direct comparisons, I would say that the Canon nFD 135 f2 is at least as sharp at f2 as the Pentax at f2.5.
The a6000 samples at f2.5 also show that CA is clearly visible at that aperture. Things do improve significantly by stopping down, though.
As is the case with many 135mm lenses, the bokeh produced by this lens is excellent, smooth stuff.
The a6000 samples at f2.5 also show that CA is clearly visible at that aperture. Things do improve significantly by stopping down, though.
As is the case with many 135mm lenses, the bokeh produced by this lens is excellent, smooth stuff.
perhaps a bit swirly here at f2.5
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nicely rendered at f4
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f2.5
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challenging background and large separation but remains pleasing
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I was generally impressed with Pentax's SMC coating when I reviewed the Pentax-M 50mm f1.4. The 135 does well when pointed directly at ligt sources, retaining contrast in most situations and producing an image free from ghosting. It is possible to get some flare under extreme circumstance, but overall it performs well.
strong performance at f2.5
slight veiling and loss of contrast
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at f11
veiling, ghosting, and loss of contrast can occur
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Some vignetting is visible until about f4, but even wide open it's not a big deal for most applications.
f2.5
f5.6
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f4
f8
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Conclusion
Overall, the SMC Pentax 135mm f2.5 is a strong performer. It has decent sharpness, great bokeh and good coatings. It is also beautifully put together with a mechanical quality that makes it a pleaseure to shoot with. Inevitably, and perhaps unfairly, I can't help but compare it to another 135mm lens I own (and love), the Canon nFD 135mm f2. That lens is just a lot more fun to shoot with, offers shallower depth of field, closer focusing (1.3m vs 1.5m), slightly smoother bokeh, and appears to be sharper. The only advantage the Pentax has is a slightly lower weight, but the difference is not very noticeable. Of course, the Canon costs twice as much, so for those looking for a high quality short telephoto at a decent price, the Pentax is certainly a good choice.
Any experience shooting with this lens or other classic 135s? Would love to hear what you think in the comments below.
Related lenses
Sample Images
Overall, the SMC Pentax 135mm f2.5 is a strong performer. It has decent sharpness, great bokeh and good coatings. It is also beautifully put together with a mechanical quality that makes it a pleaseure to shoot with. Inevitably, and perhaps unfairly, I can't help but compare it to another 135mm lens I own (and love), the Canon nFD 135mm f2. That lens is just a lot more fun to shoot with, offers shallower depth of field, closer focusing (1.3m vs 1.5m), slightly smoother bokeh, and appears to be sharper. The only advantage the Pentax has is a slightly lower weight, but the difference is not very noticeable. Of course, the Canon costs twice as much, so for those looking for a high quality short telephoto at a decent price, the Pentax is certainly a good choice.
Any experience shooting with this lens or other classic 135s? Would love to hear what you think in the comments below.
Related lenses
Sample Images
