Sony a7 torture test with Leica, Zeiss, Voigtlander rangefinder lenses

October 19th, 2013

UPDATE – January 26, 2014

I was finally able to run the test I originally wanted to back in October. Please click the link to read the Sony a7R vs. Leica M9 shootout with 20+ Leica, Zeiss and Voigtlander rangefinder lenses.

Continue reading below for the Sony a7 with various rangefinder lenses. Note, if you’d rather access images one by one instead of a large zip file download for each lens, please see the images posted on my Flickr page.

———

I was able to briefly borrow and test a preproduction Sony a7 camera along with the new Carl Zeiss Sonnar T* 35mm f/2.8, Carl Zeiss Sonnar T* 55mm F1.8 and Sony 28-70mm f/3.5–5.6 OSS FE lenses. Unfortunately it wasn’t the a7R, in which I am more interested for the purposes of adapting rangefinder lenses. But this provided a good opportunity nonetheless to generate some images to help me (and hopefully also you) determine whether or not the a7 is a possible platform for rangefinder lenses.

First off, the images presented here are in no way intended to be examples of creative photography. Given I had 1.5 hours with the camera on a gloomy morning, and the burning question in the minds of many is how well this new Sony camera will work with adapted rangefinder lenses, an infinity focus test was in order. Why an infinity focus test? Because when a lens is focused at infinity, the rear element of the lens is typically closest to the sensor, meaning for certain lens designs, the light rays traveling to the sensor arrive at a strongly non-perpendicular angle, rather than straight at the sensor, which results in image quality degradation if the sensor isn’t well optimized for such types of lenses. The results tend to be edge color shifts and/or edge/corner smearing of the image.

This generally isn’t a problem with lenses adapted from SLR systems because such lenses must be design with the mirror box in mind, meaning the lens sits farther away from the image plane and the light rays arrive at a more perpendicular, and preferred, angle. Rangefinder systems never had the mirror box and the lenses were made to sit much closer to the image plane. Not such a big problem with film (other than perhaps light falloff into the corners), but definitely not desirable with digital sensors due to the many sensor ‘toppings’ that contribute to image degradation when light rays arrive at a strong angle.

Anyway, there are much better technical explanations available online, particularly in this PDF from Zeiss. See page 12, points 2 and 3.

I’m required by Sony to state that the camera and Sony lenses used to create the images presented here were all preproduction models and the image results are therefore not necessarily indicative of results that will be obtained from production units once they become available.

However, unless Sony makes major revisions to the sensor package itself, I doubt results with the rangefinder lenses tested here will improve considerably once production units are available.

The lenses tested, in order of focal length and maximum aperture:

Voigtlander Ultra Wide-Heliar 12mm f5.6 Aspherical (LTM version which is identical to the current M mount version) (referred to as CV12)
Voigtlander Super Wide-Heliar 15mm f4.5 Aspherical M (referred to as CV15)
Leica Summilux-M 21mm f1.4 ASPH. (referred to as 21 Lux)
Zeiss Biogon T* 21mm f2.8 ZM (referred to as ZM21)
Leica Super-Elmar-M 21mm f3.4 ASPH. (referred to as 21 SEM)
Leica Summicron-M 28mm f2 ASPH. (referred to as 28 Cron)
Voigtlander Nokton 35mm f1.2 Aspherical VM II (referred to as CV35)
Canon 35mm f2.0 LTM (a lens from the late 50s-early 60s)
Zeiss C Biogon T* 35mm f2.8 ZM (referred to as ZM35C)
Sony Carl Zeiss Sonnar T* 35mm f2.8 (newly announced with the a7/a7R)
Voigtlander Nokton classic 40mm f1.4 (referred to as CV40)
Leica Summilux-M 50mm f1.4 ASPH. (referred to as 50 Lux ASPH)
Canon 50mm f1.4 LTM (a lens from the late 50s-early 60s)
Voigtlander Nokton 50mm f1.5 Aspherical LTM (optically identical to the current M mount model, though apparently there may be some coating differences) (referred to as CV50)
Zeiss C Sonnar T* 50mm f1.5 ZM (referred to as ZM50C)
Zeiss Planar T* 50mm f2 ZM (referred to as ZM50P)
Sony Carl Zeiss Sonnar T* 55mm f1.8 (newly announced with the a7/a7R)
Sony 28-70mm f3.5–5.6 OSS (newly announced with the a7/a7R)
Leica Summarit-M 90mm f2.5 (referred to as 90 Summarit)

Test scenes include one view overlooking downtown Hamilton, Ontario, from the escarpment brow, one intended to show ‘bokeh’ differences between the 35mm and ~50mm lenses, and one ‘brick wall’ test of foliage with the wides and up to ~50mm lenses (though not including the LTM 50s, CV40 and Sony zoom due to time and weather constraints).

I had also intended to shoot the exact same scenes with the same lenses on the Leica M9 (though obviously not including the new Sony lenses), but I ran out of time, and it started to rain. This would have provided a ‘control’ reference against which to compare the results from the a7. I’ll spill the beans now – none of the rangefinder lenses performed as well on the a7 as they do on the M9, specifically referring to image smearing into the edges/corners. Some are not so bad and are good enough when stopped down sufficiently, but some are outright horrible (ZM21, 28 Cron), to the point where one would think the lens was defective.

Naturally there were some variable that couldn’t be tested, such as whether the Novoflex NEX-Leica M adapter I used was perfect. I had a Kipon adapter as well, but no time to run a duplicate set of test images to see if, or how much, the adapter influenced the results. Therefore, take these results for what they are and weigh them against other tests that will certainly soon appear online.

Everything was shot on a tripod with the two second timer at ISO 400. While perhaps not optimal, I wanted to keep shutter speeds somewhat reasonable considering the gloomy weather (even though a tripod was used). Images presented here were taken directly and uncorrected from in-camera Jpegs. I also shot RAW, but don’t have a way to convert those yet. While it certainly would be possible to improve color and tonality, nothing could possibly improve image rendering into the edges/corners with some of the lens combinations. In-camera lens corrections (vignetting, chromatic aberration, distortion) were disabled, in case some or all of these might also apply to non-native lenses. ISO noise reduction was also disabled, though I suspect it never entirely turns off. The camera was set to manual focus and each lens was focused on the steeple in the center of the frame using 11.7x magnification. No attempt was made to correct for focus shift, which was certainly a problem with at least the ZM50C.

Infinity Focus

Bokeh

Foliage

DOWNLOADS

By lens:

CV12
CV15
21 Lux
ZM21
21 SEM
28 Cron
CV35
Canon 35mm f2.0 LTM
ZM35C
Sony Carl Zeiss Sonnar T* 35mm f2.8
CV40
50 Lux ASPH
Canon 50mm f1.4 LTM
CV50
ZM50C
ZM50P
Sony Carl Zeiss Sonnar T* 55mm f1.8
Sony 28-70mm f3.5–5.6 OSS
Leica Summarit-M 90mm f2.5

By scene:

infinity: 12mm-21mm
infinity: 28mm-40mm
infinity: 50mm-55mm
infinity: 28-70mm zoom and 90mm

bokeh 35mm
bokeh 50mm-55mm

foliage 12mm-15mm
foliage 21mm
foliage 28mm-35mm
foliage 50mm-55mm

Note, the download links will take you to zipped files hosted on Google Drive. These are quite large, and at full resolution (though compressed somewhat more after applying the watermark shooting information, than what came out of the camera). The full set of links is several GB, so be warned.

My take on the results: I’m hoping these lenses will fare better on the a7R. Results on the a7 are for the most part disappointing. All I can surmise at the moment is that the toppings on the a7’s sensor work against achieving optimal (or in some cases, good enough) results with the rangefinder lenses I had available for this test.

What may also be the case with this new system from Sony, as was with the Nex cameras, is that compatibility with adapted lenses will be model specific. Future cameras may work better, but some may be even be worse…

Those looking to adapt SLR lenses will probably achieve much better results with the a7 and the new Zeiss lenses look to be quite good, especially the 55. Sure, it’s pricy for an f/1.8 lens, but it looks great right from wide open.

And of course a short pitch at the end to encourage you to kick some cash my way, in thanks for this information, by making any purchase at B&H Photo Video through the affiliate link and search box below…

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Equipment mentioned in this article:

50mm bokeh shootout on Leica M9

July 2nd, 2013

This isn’t a definitive 50mm test in the least, rather, an opportunity to give a quick ‘bokeh’ impression of a number of 50mm lenses available for the Leica M mount, shot at 1 and 1.5m distances common to all of the lenses. Some will focus closer, but in order to keep the results consistent, 1 and 1.5m were chosen.

Lenses in the shootout, in the order they appear below:

Leica Summilux-M 50mm f1.4 ASPH. (modern)
Zeiss Planar T* 50mm f2 ZM (modern)
Voigtlander Nokton 50mm f1.5 Aspherical LTM (note that the link is the second version of this lens, but I tested the first version, with the ‘same’ optics, though apparently different, not as effective coatings) (modern)
Canon 50mm f1.4 LTM (late 50s, early 60s)
Zeiss-Opton Sonnar T 50mm f1.5 (Contax rangefinder lens in Amedeo Contax-Leica adapter) (post WWII)
Nikkor-SC 5cm f1.4 LTM (1950s)
Ernst Leitz Summarit 5cm f1.5 LTM (1950s)
Voigtlander Nokton classic 40mm f1.4 (multicoated version – while not 50mm, added for kicks) (modern)

The set-up: Camera was on a tripod and lenses were rangefinder focused on a specific target to the best of my ability. There is some shot to shot variation because it was slightly windy. Since this is primarily for bokeh quality analysis, trying to nail perfect focus, or compensating for focus shift (common in a number of the lenses) was not a priority (though I did attempt to adjust for focus shift with the Zeiss-Opton). DNG files were converted in Lightroom 4.4, set to the same WB for all scenes, as were exposures. Only the 1.5m scene had some exposure compensation and curve tweaks applied in post to compensate for a somewhat darker metering by the camera. No additional shadow recover, clarity, saturation,lens profiles, chromatic aberration correction, etc. was applied. Standard Lightroom sharpening was applied.

Up first are two backlit scenes shot at 1m and 1.5m. The third scene was in open shade at about 1m.

Low rez files are shown below for wide open performance of each lens.
Full 18MP Jpegs can be downloaded from the links at the bottom of the page. The two backlit scenes include images shot from wide open until f/5.6 while the third scene includes from wide open until f/2.8.

1m distance, backlit:







1.5m distance, backlit:







1m distance, open shade:







Basic observations:

The Leica Summilux-M 50mm f1.4 ASPH. is the smoothest rendering of the bunch and at f/2 has larger blur disks than the Zeiss Planar T* 50mm f2 ZM. This has always been my finding – that fast lenses shot stopped down to the equivalent wide open aperture for other lenses, render larger blur disks.
While these are all 50mm lenses (ignoring the Voigtlander 40mm), their actual focal lengths vary slightly, with the Zeiss Planar T* 50mm f2 ZM being the widest of the bunch, which probably is a slight disadvantage when it comes to blurring out background details.
While the Summilux is the most expensive of the bunch, it probably has one of the most annoying aperture shapes as it stops down through ~f/2-5.6, which could be nicknamed ninja star or saw blade. This can impact the shape of specular highlights, already starting at f/2. It’s another factor that reinforces my belief that Leica lenses really are made for shooting either wide open, or well stopped down. It certainly does have a nice, smooth quality wide open.
The Voigtlander is actually fairly close in look to the Summilux in these examples. It was shot uncoded (as were all the vintage lenses), which perhaps accounts for the greater wide open vignetting.
The 50s-60s vintage lenses – the Canon, Nikkor, Leitz Summarit and Zeiss-Opton all have much more energetic and ‘less perfect’ bokeh, yet I find them all quite interesting for their individual character.

High-rez downloads:

1m distance, backlit 127MB
1.5m distance, backlit 165MB
1m distance, open shade 60MB

Since bokeh analysis is extremely subjective, I’ll just leave it at this and close with “you can never have too many 50mm lenses.”

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Sony RX1 Sonnar 35mm vs. Leica M9 and Biogon 35mm ZM lenses review

March 13th, 2013

Sony DSC-RX1 Carl Zeiss 35mm f/2 Sonnar vs. Carl Zeiss 35mm f/2 Biogon ZM comparison review

The Sony DSC-RX1 ultra-premium compact full frame camera with Carl Zeiss 35mm f/2 Sonnar lens has received a lot of praise for its technical achievements. Not only is it the smallest camera in its class (it’s perhaps in a class of its own at the moment), but it also attains very high levels of image quality, comparable to what one can produce from full frame interchangeable lens systems.

The Sonnar lens is the purpose of this review. More specifically, an examination of how well it and the RX1 hold up against currently available Carl Zeiss 35mm ZM-series lenses on the Leica M9 full frame 18MP camera.

Why the ZM lenses and not the ZE/ZF lenses? For a couple reasons:

1) It has been stated by some that for the price of the RX1 and a few accessories, one comes into used M9 territory. This is more so the case now that Leica has released the ‘M’ and used M9 prices have dropped below $4,000. For ‘only’ another $1,000 or so, one can add a quality ZM lens to the M9 and benefit from an interchangeable lens system not much larger in size with more flexibility than the RX1. Both options are much smaller than currently available full frame DSLRs with Zeiss ZE/ZF lenses.

2) I happen to use the M9 and am curious about how well the RX1 compares, and have access to both ZM 35mm lenses. If time and opportunities permit, I may revisit this comparison with some additional Leica M-series lenses.

Click on the image at top or here to continue to the review.


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