Lens Shoot-Out (50mm)

Last updated on November 14, 2011
Contents
Introduction
The Lenses Tested
Overall Scene
Sharpness & Contrast
Fringing and Chromatic Aberration
Edge Performance (Wide Open)
Corner Performance (Wide Open)
Conclusion
Further Research

Introduction

This is the first in a series of "shoot-outs" and covers the 50mm focal length. These aren't intended as in-depth scientific tests so much as illustrating differences between lenses as far as character, bokeh, at/near wide open sharpness and focus shift. In order to promote as direct a comparison as possible, no in-camera firmware corrections are applied - so vignetting is also well represented. We drew the line at wide open and f/2.8 shots to keep things simple. "Wide open" varies from lens-to-lens, but these lenses all have f/2.8 as the "lowest common denominator." Stopping down only serves to increase depth of field and sharpness and reduce vignetting to the point where they'd all look essentially the same by f/5.6 or f/8.

Based on feedback, we'll refine this shoot-out and as it develops - use it as a template for future shoot-outs. The next one in the series will be based on the 35mm focal length.

The Lenses Tested

The lenses up for comparison in this test are (and shown above from left to right):

The Color Skopar in this case is an LTM lens with the appropriate Voigtländer (Type I) adapter. The others are all natively M mount. Select the links for more in-depth reviews of each particular lens, which is beyond the scope of this shoot-out.

These images were all shot on a Leica M9 set to ISO 160 with Lens detection set to "Off" via MENU and White balance to "Auto" via SET (though normalized during import to "Daylight"). Without the firmware corrections, vignetting will show unaltered. The camera was mounted on a tripod and a cable release was used. Other than scaling, no image enhancements or modifications were performed. Lenses all had their hoods attached and focused on the subject at approximately 2.5m.

Overall Scene

The first set is the full image from camera so as to gauge general depth of field and bokeh characteristics. Notice the slight variation in exact field of view between the lenses.


Nokton @ f/1.1

Nokton @ f/2.8
 
   

C Sonnar @ f/1.5

C Sonnar @ f/2.8
   

Planar @ f/2

Planar @ f/2.8
   

Color Skopar @ f/2.5

Color Skopar @ f/2.8

Sharpness & Contrast

The second set are 100% crops of the focal point and center of the image. This allows for a better view of the relative sharpness both wide open and stopped down slightly. Needless to say, the slower lenses are generally sharper wide open than their faster counterparts and contrast increases when stopping down as well. The exception being the Planar, which is already contrasty wide open.


Nokton @ f/1.1

Nokton @ f/2.8
 
   

C Sonnar @ f/1.5

C Sonnar @ f/2.8
   

Planar @ f/2

Planar @ f/2.8
   

Color Skopar @ f/2.5

Color Skopar @ f/2.8

Fringing and Chromatic Aberration

The third set are 100% crops of a high contrast area of the image to illustrate purple fringing and chromatic aberration. Faster lenses are generally more susceptible to this than slower lenses, and appears more so wide open than stopped down. Purple fringing is not caused by a shoddy lens or sensor defect. It is most often caused by overexposure and high-contrast transitions in the scene (e.g. white sky, dark branches).


Nokton @ f/1.1

Nokton @ f/2.8
 
   

C Sonnar @ f/1.5

C Sonnar @ f/2.8
   

Planar @ f/2

Planar @ f/2.8
   

Color Skopar @ f/2.5

Color Skopar @ f/2.8

Edge Performance (Wide Open)

These are 100% crops of the central, top edge area of the images to illustrate edge performance wide open. Notice the clarity of the details and how they all show chromatic aberration to varying degrees. Perhaps not surprisingly, the Planar fares the best in this test (while the Nokton fares the worst) with the least chromatic aberration and the highest definition of details. The edges and corners of fast lenses are generally the areas to watch. The slower or more highly corrected the lens, the better these areas will typically be (e.g. the Leica Summilux-M and Noctilux ASPH lenses). Considering the cost of the lenses tested and the typical scenario for shooting wide open however, this generally isn't a huge concern. If you like to shoot wide open during the day, with (or without) a neutral density filter to maximize the narrow depth-of-field and bokeh effects however, you might be disappointed.

For both this edge and the following corner performance comparisons - in the interest of keeping this shoot-out manageable, we're only showing wide open shots. Naturally, as you stop the lenses down they perform better in these areas. Granted, these are not apples-to-apples comparisons - but if there's enough demand we'll include f/2.8 comparisons for that.


Nokton @ f/1.1

C Sonnar @ f/1.5
   

Planar @ f/2

Color Skopar @ f/2.5

Corner Performance (Wide Open)

In this set of 100% crops of the top left corner of the images, notice the treatment of out-of-focus areas (bokeh). We see the effects of field curvature and the smearing of detail especially on the faster lenses. The slower ones fare better here, again not surprisingly. The corners are generally the areas of worst performance, regardless of lens.


Nokton @ f/1.1

C Sonnar @ f/1.5
   

Planar @ f/2

Color Skopar @ f/2.5

Conclusion

What's interesting in comparing these shots is the differing bokeh, sharpness, contrast and amount of chromatic aberration. They're all 50mm lenses and have the same depth of field. However, each lens design has its own "signature" including the "roll off" or "transition" from in- to out-of-focus areas. The handling of blur or "bokeh" is also a very individual thing - both in terms of lens design and shooter preference. Of course, a lot of this is due to the differences between what exactly "wide open" is for each lens. The Nokton opens up to f/1.1, while the Color Skopar only opens up to f/2.5 for example. Thus the f/2.8 comparison shots where you can compare lens against lens directly.

  • The Nokton looks "the worst" wide open as far as sharpness, contrast and chromatic aberration but one has to remember... This is an f/1.1 lens after all! Most of the time, shooting at such an aperture is done in low, contrasty light anyway - where it won't be an issue. Furthermore, the increased shutter speed as a result will likely provide a sharper image just from reducing (or eliminating) motion blur in such situations. Stopping down to f/2.8 still doesn't clear up all issues, but things do improve. The bokeh, often criticized with this lens (at least when compared to the Noctilux as it often is) varies from "nervous" to quite smooth, depending on a variety of factors (aperture, distance to background and detail of same mostly). It doesn't even compare to the 35mm f/1.2 Nokton in this regard. Generally, if you can help it - you'll want to shoot the Nokton at around f/1.4. Still fast, but nearly every metric (including something subjective like bokeh) improves from wide open. The test images do reveal a bit of focus shift setting in at f/2.8 but it's a bit worse at f/4 and shifts in the opposite direction of the Sonnar.

  • The Sonnar images also show a hint of focus shift and can be detected in the 100% crops (as this lens is optimized for f/2.8). There is also some slight chromatic aberration wide open which disappears quickly stopping down. Contrast improves from wide open slightly. While it's easy to dismiss the Sonnar when comparing it strictly on performance, it has an awful lot of wonderful character which many appreciate. Stopped down to f/4 and f/5.6 it very quickly comes up to modern standards of performance. You could say it's two lenses in one.

  • The Planar images show that this lens is sharp and contrasty from wide open. It is sharp across the frame almost from wide open and is the only lens tested that exhibits very little if any chromatic aberration. Clearly the winner of this shoot-out in terms of ultimate performance. The only competition to the Planar would come from the Leica Summicron, Summilux and newest Noctilux lenses - at an impressive jump in price at each level. The value of the Planar therefore, is very hard to beat.

  • The Color Skopar is simlar to the Planar in many ways but doesn't quite reach the same performance. There's additional softness into the edges and corners and more chromatic aberration. But considering the cost and size of this lens, it puts on a very good show and is the smallest lens of the group - which makes it a very pocket-friendly, every day option. The quick focus action and finger tab are a real bonus. Being made mostly of brass it's also surprisingly dense given its size.

So what's the verdict? Bang for the buck and technical performance - the Planar wins. It's sharp, reasonably small and has excellent overall performance. Smallest size while maintaining good performance goes to the Color Skopar, which also represents very good bang for the buck considering the price - the cheapest lens in the group.

The Sonnar is a bit of a chameleon as it offers both character and performance depending on the aperture; it offers the former as well as speed wide open but shifts to the latter stopped down. The Nokton, while good - should really be considered more of a low light lens. Wide open it's not fantastic, lacking the charm of the Noctilux' bokeh which is more predictable and smoother by a long shot (though it is slightly sharper). Like the Sonnar, it exhibits some focus shift and it's a rather large, heavy lens. If you're going to shoot the Nokton at f/1.4 anyway - you might consider the Sonnar instead. Smaller, lighter and much nicer character. However, when it comes to speed (and if nothing else will do) the Nokton is the only choice.

In the end, they're all very good lenses and which you should choose depends entirely on what you expect or need from a 50mm lens. Stopped down to f/4 or f/5.6 for more day-to-day shooting they're all excellent and even relatively the same across the board. It's a balance of size/weight, speed, character and performance. Cost-wise they're all pretty close and in fact, you could buy all four for the price of the Leica Summicron! Build-wise they're all similar as well, with the Zeiss lenses perhaps a bit more refined than the Voigtländer - but this is where the Summicron shines and outclasses them all.

Further Research

Besides the individual lens reviews (and their own sample images), you might also want to check out the various (Nokton, Sonnar, Planar and Color Skopar) sample image threads here in the forum.