If you’ve read the previous 85mm test, you won’t be surprised to hear that the Zeiss ZF 85mm f1.4 was returned to the dealer: weak close range performance and a painfully tight focusing ring were cited as reason enough for dissatisfaction.
Fast forward one month, and the Mark I Canon 85mm f1.2 L has been replaced by the Mark II: new coatings promising improvements in flare resistance and chromatic aberration. I was so pleased with the performance of the 85L that I sought more of a good thing and upgraded to the Mark II.
Up against our seasoned on-brand contender is the Pentax 85mm SMC-A* f1.4 which was officially replaced by a different optical design when ‘upgraded’ to autofocus in 1992. Anecdotal reports, and the rare tests available, seem to indicate that the change didn’t represent progress in all areas. In particular, wide aperture performance of the manual focus SMC A* was generally considered superior to its antecessor, whereas the FA lens appeared to better its predecessor in the f5.6-f11 range.
The manual focus lens retains a reputation as a lens of the very highest calibre. That, plus its rarity, puts it one notch below the Zeiss Anniversary category of desirability. The occasional eBay sale fetches far more than the more common FA 85mm f1.4. However, as far as I know, however, no tests have ever been published on a Canon body, and it is rarely considered by even the most zealous adapted-lens enthusiasts. What you are about to see may change that.
One word of warning about the following test: because the SMC A* 85mm f1.4 is such a rare and expensive beast, I was reluctant to make the small, but irreversible, modification that makes it suitable for use on a full frame Canon body such as the 5D or 1Ds II. Pentax users still pay good money for them. Having committed to thus chickening out, the least I could do to make amends was to test both lenses on the 400D (AKA Rebel XTi), which is more revealing across the central two thirds of a proper frame, but which sadly tells us nothing about the corners of a 35mm image. If it proves itself here, I will mod it for full frame testing later!
[nextpage title=”Close Range (f1.4)”]
Extreme corner crops from Canon 400D frame (150% magnification)
To see what’s really going on in the corners, these 100% crops have been further enlarged to 150% using Bicubic Sharper, after some modest USM was applied. You’ll note in all cases that the Pentax 85mm is a longer focal length than the Canon. Which, if either, are truly 85mm is anyone’s guess.
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| Canon 85mm f1.2 L MkII at f1.4 (corner) | Pentax SMC A* f1.4 wide open (corner) |
That is an immensely impressive capture by the Pentax SMC A – wide open, against the Canon half a stop down. You’ll have to excuse me while I go a bit purple here, because that is the sharpest ‘corner’ I ever seen any lens produce at this aperture (f1.4). Just stunning. For the centre frame assessment, we’ll revert to 100% views:
Centre frame crops (150% magnification)
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| Canon 85mm f1.2 L MkII at f1.4 (centre) | Pentax SMC A* f1.4 wide open (centrer) |
However, like a true champ, the 85L Mk II refuses to be counted out, counterpunching with a centre frame performance that puts it back in the fight. Better contrast, higher resolution and generally more yumminess. The Pentax is still ahead on points, though . . .
[nextpage title=”Close Range (f4)”]
Extreme corner crops (full frame re-res’d to 6000 pixels)
Again, because this pair are so closely matched, the 400D capture has been resampled to 6,000 pixels wide (from 3,888 px) and matching crops taken. Again, allowance must be made for a slight advantage handed to the Pentax whose longer focal length allocates a few more microlenses the privilege of rendering her Maj’s noggin.
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| Canon 85mm f1.2 L MkII at f4 (corner) | Pentax SMC A* f1.4 at f4 (corner) |
I must confess this has me all wobbly: I was not expecting the Pentax to outperform the Canon here. The 85L has a reputation for being peerless at this aperture: yet the SMC is clearly sharper, better delineated and clearly comparable in colour rendition. Truly stellar ‘corner’ performance – well worth the full frame mod?
Centre frame crops (from full frame re-res’d to 6000 pixels)
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| Canon 85mm f1.2 L MkII at f4 (centre) | Pentax SMC A* f1.4 at f4 (centre) |
Even at nearly 200% enlargement, this is a tough one to call. The Canon 85L II appears a little more contrasty centre frame, as it did at f1.4. There is (quite literally) the merest hair more resolution in the Pentax image, but this apparent advantage is mitigated by the larger image size. On balance, I think perhaps the Canon does just enough to be preferable, but we are seriously nitpicking here . . . .
[nextpage title=”Distance Test (f1.4)”]
Extreme corner crops (full frame re-res’d to 6000 pixels)
The test target here a ‘domestic scene’ at a distance of approximately 100 metres.
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| Canon 85mm f1.2 L MkII at f1.4 (corner) | Pentax SMC A* f1.4 at f1.4 (corner) |
All over again we see better contrast, resolution and colour in the corners of a 400D frame from the Pentax. The SMC A* just makes the Canon look bad, any honestly it isn’t: I’ve not tested anything the 85L didn’t embarrass at wide apertures, but it has truly met its match in the shape of the A* f1.4.
Centre frame crops (from full frame re-res’d to 6000 pixels)
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| Canon 85mm f1.2 L MkII at f1.4 (centre) | Pentax SMC A* f1.4 at f1.4 (centre) |
At distance, we see an alarming bloom of chromatic aberration around the house window from both lenses, but quite horrifically in the Pentax’ case. Attempting to squint through the ghastly haze we find that the SMC A* is even better at distance than it is at close range, producing cleaner, sharper captures than the Canon L time after time, but that CA is gruesome. The Canon’s is much easier to correct, too: neatly adhering to a few pixels’ boundary, but the Pentax’ wild glow is tough to repair.
[nextpage title=”Distance Test (f2.8)”]
Extreme corner crops (full frame re-res’d to 6000 pixels)
The test target here a ‘domestic scene’ at a distance of approximately 100 metres.
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| Canon 85mm f1.2 L MkII at f2.8 (corner) | Pentax SMC A* f1.4 at f2.8 (corner) |
The apparent slight advantage the Canon seems to enjoy here in the corner must be partially offset by the fact that it had slightly stronger, more contrasty light in this exposure, just enough to lift the highlights a little more. In truth, there’s nothing to choose between them at this aperture and distance.
Centre frame crops (from full frame re-res’d to 6000 pixels)
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| Canon 85mm f1.2 L MkII at f2.8 (centre) | Pentax SMC A* f1.4 at f2.8 (centre) |
Mercifully, by f2.8 both lenses are largely aberration free. The Pentax still has a whisper lurking at the window’s edge, but bear in mind that you’re looking at 200% enlargements. Again, the stronger light slightly favours the Canon capture, but I’m not convinced it represents a big score in its favour. Again, they’re very close.
[nextpage title=”Distance Test (f8)”]
Extreme corner crops (full frame re-res’d to 6000 pixels)
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| Canon 85mm f1.2 L MkII at f8 (corner) | Pentax SMC A* f1.4 at f8 (corner) |
As if to redress the balance from the f2.8 tests, at f8, the light was a fraction stronger while shooting the Pentax, favouring its rendition of the scene. And once again, I must add that the Pentax isn’t really this much better than the Canon at this aperture. In equal light, they’re impossible to tell apart at distance on a 1.6x sensor.
Centre frame crops (from full frame re-res’d to 6000 pixels)
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| Canon 85mm f1.2 L MkII at f8 (centre) | Pentax SMC A* f1.4 at f8 (centre) |
Well illustrating the difficulties facing the real world tester (namely the inconstancies of the real world), the Pentax’ apparently sharper rendering is mainly the result of fractionally less diffusion in the atmosphere. In England, the light is rarely identical two minutes’ running. Suffice to say that the Pentax doesn’t outperform the Canon at long range as clearly as it does at close range.
