Cosina Voigtlander (CV) is a japanese camera maker that specializes in 35mm film rangefinder cameras. They also make their own lenses and are quite good at it since Cosina is the manufacturing partner of Carl Zeiss, AG. While the lion’s share of lenses they make are for Leica Thread Mount (LTM) and Leica M-mount, they do make a few SLR lenses in Nikon F and Pentax KA mounts. Today I present to you the CV Ultron 40mm f2 SL II.
Specs
Two surface Aspherical Element lens for maximum correction
CPUs for metering compatibility with Nikon or Pentax digital SLRs
Compact Pancake lens extends only 24.5mm from lens mount (Nikon AIS)
Six elements in five optical groups
9 Aperture blades
Size 200 grams, 63mm diameter, 24.5 length from lens mount (AIS)
Filter size 52mm
Close Up to .45 meter (1:7) without close up, close up range of .38 to .25 meter (1:4) with close up lens
Angle of view with film 57 degrees
Smallest aperture f/22
Included with the lens is the dome shape lens hood and the close up lens.
Features
The CV Ultron 40mm is a pancake lens, very short and compact by design. Made completely out of metal and glass, it is surprisingly very light, tipping the scales at a mere 200 grams. When mounted on my D300+MB-D10 it looks positively puny.
That being said, the lens makes carrying my D300 very, very easy even with the MB-D10 grip attached. With the D300′s DX sensor, this lens’ effective focal length is 60mm, making this a nice, wide-ish portrait lens suitable for walkabout. But as Master Yoda said, “Size matters not.” And like the diminutive Jedi Master, this little guy packs a big wallop.
Fast and sharp, the lens has a medium focusing throw, going from minimum focus to infinity in 180 degrees. The lens included a small dome-like lens hood (this has to be seen to be believed) and a screw-on close-up lens which reduces the minimum focusing distance from 38cm to 25cm (about a foot for the metrically challenged).
Wait a second, focusing throw?
Yes, this is a manually focused lens. In fact, all of CV’s lenses are manually focused – not an AF motor in the bunch. However, this lens (and it’s 58mm Nokton stable mate) are both CPU Matrix lenses that support Program, Shutter & Aperture Priority modes. The apertures can be set from the camera without having to move the mechanical aperture ring. Just set it on f22 and forget it. The camera does the rest, even in Manual mode.
Another thing to consider is that this a prime lens (fixed focal length) and zooming is achieved by moving closer to/further away from your subject (aka “sneaker zoom”).
So why would anyone buy this dinky non-zoom lens?
Besides the obvious size factor, the lens is razor sharp, has a lovely smooth bokeh (rendering of out-of-focus areas) and is quite a value for the price.
Here are some bokeh samples:
As you can see in the samples, the soft out-of-focus areas add a 3-dimensional aspect to the subjects, making them pop out of the image. The lens is also equally adept at handling color as well as black & white.
[Editor's note - all images in this article were shot using a Nikon D300 in NEF format and processed in Apple Aperture 2.1. Black & White conversion accomplished with Nik Software's SilverEfex Pro for Aperture 2. Fuji ISO 100 film was simulated.]
One thing to remember when using a fast prime lens is that the plane of focus with the lens wide open is very thin. The faster the lens, the thinner the plane of focus. This next shot shows how thin the plane of focus is.
As you can see above, the camera is focused on the balloons behind my son’s head. The balloons are in sharp focus, but my son’s face is slightly out of focus. With a manually focused lens, you have to be extra-careful to make sure that the focus is on the right spot. This end, Nikon has provided the D300 with a focusing aid that tells you when the subject under the center spot of the viewfinder is in focus. The Nikon D3 and D700 share this feature with some enhancements.
Test Photos
The set of test shots above show the lens’ performance at various f-stops ranging from f/2 (wide open) to f/22 (fully stopped down in 1/2 EV increments).
At f/2, the lens’ paper-thin plane of focus is readily apparent. For the record, focus was set on the bundles of thread in the center of the photo in every shot. By clicking in the individual photos, you can see larger versions including full-size (12.3Mpx) images. As you can see, items a couple of inches behind or in front of the threads are softly out-of-focus.
As the lens is stopped down, the scene is pretty much in focus by about f/5.6 with maximum detail rendered about f/11. Corner sharpness is very good and center sharpness is excellent. Color rendering is excellent as well. Chromatic aberration is pretty much non-existant even stopped down thanks to the aspherical lens element in the design.
One last test: the included close up lens. This lens is screwed into the dome hood and does not interfere with any filters mounted between the hood and the lens barrel.
On the left you can see the diminutive close-up lens and on the right a test shot of my Leatherman Skeletool from about 25cm (1 ft) away. The close-up lens does not add any distortion.
Price
The lens is available from major online photo stores like B&H, Adorama, and Cameraquest (the main Voigtlander importer for the United States). The price is $379 which is a bargain considering how well built this lens is and how well the optics perform. Zeiss lenses for Nikon cost about 2-3x as much.
Conclusion
The CV Ultron 40mm F2 SL II is an excellent choice as a prime lens for walkabout use. On a D300, it is a lovely short tele portrait lens and on the D3/D700 it is slightly wider than a normal lens (50mm). It is available in Nikon F-mount (the one I have) and Pentax KA-mount. If you have either of these camera brands, you want to get this lens.
