Sony A7R vs Leica M Monochrom: Resolution Contest
- MM with 35mm Summarit-M f2.5 vs. Sony A7R with Sony Zeiss 35mm f2.8 Sonnar (review).
- Leica MM with Zeiss 50mm ZM Planar f2 vs. Sony A7R with Sony Zeiss 55mm f1.8 Sonnar (review).
In both cases, I have chosen subjects that are at middle distance i.e. scenics, so of course the results could be very different closer in. However, lenses with field curvature are normally worse at distance, so this should be a tough test of both lenses.
The methodology was simple: put them both on a tripod, focus as best I could (rangefinder for the Leica and live view with the A7R) and fire off a number of frames using the self-timer. I then uprezzed the MM files in Lightroom to the same dimensions as the A7R files (which were converted to B&W). I then applied the same sharpening to both, using what I typically use for the A7R files. This seemed about right, as confirmed by experimentation that yielded no further improvement to the MM files. I also made changes to the two cameras’ files to make them broadly match in contrast and overall image parameters, so it at least feels like we are comparing apples to apples.
As for ISO, I used 320 for the MM and 200 for the Sony. This was necessary to ensure that the Sony A7R shutter speed remained at 1/250th or higher. Although I know my camera has no shutter vibration visible with a 35mm lens, I wanted to be sure nobody cried foul because of this. I can say with certainty that the difference in resolution between 100 and ISO 200 can be measured only in baby gnats’ whiskers, where the gnats have come from Lilliput. At ISO 100, there might have been an absolutely tiny improvement but not of the sort that will change anything you’re going to see.
For the purposes of this test, I decided to show files at f8, because all lenses perform superbly at this aperture and don’t get any better in the corners. Added to this, there is sufficient depth of field to take in a 3D subject somewhat representative of real world usage. While edge-to-edge performance at f0.1 is very interesting, it is rarely applicable (center performance mattering far more at very wide apertures). What I wanted to show here was how the sensor & lens combos perform in their ideal zone. I may try to repeat this test using a flatter, closer subject where wider apertures can be compared. However, I know that the Summarit is hardly a world-class performer at such apertures and so it will tell us very little aside from which lens is better wider open.
For this first subject, please note that the large tree (the point of focus being on the large knot) is in front of the smaller trees behind. Depth of field largely covers this at the apertures shown below, but it will also highlight any curvature issues. If the field curves forwards at the edges, as it does with some lenses, the rearmost trees at the edges will suffer tremendously as the plane of focus bends towards the camera and away from the trees.
Lets compare the 35mm pairings at f8.
Sony A7R vs Leica M Monochrom: Analysis
My personal interpretation is that for practical purposes this is a dead heat. After inspecting the original files repeatedly in LR, I would say that the two are about equal on centre. At the edges, the Leica combo appears slightly ahead in the. In the midfield, in one area one has a slight edge, but then I look somewhere else and change my mind. In terms of contrast, both do similarly with regard to holding the twigs against the bright sky, with the Leica perhaps doing a bit better. I think both perform admirably and in line with what I would expect, having owned both for some time. Upon extreme magnification the fine detail on the A7R is a touch smoother as nothing has been uprezzed, whereas on the Monochrom, the fine detail appears a bit edgier, in part due to detail that was only just being recorded at the pixel level, being uprezzed. Overall, I really don’t see one being meaningfully better than the other.
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