"Fisheye Lens"

One day, an idea popped up in my head - taking circular fisheye pictures.

I have a Yashica ML Fisheye 15mm F2.8 for the CONTAX/YASHICA mount, but this is a diagonal fisheye lens. The famous SIGMA Fisheye 8mm F4 seems to be the only circular fisheye lens currently available as new (actually it has recently been renewed and now is F3.5). Nikon used to make 6mm (220 degrees angle of view!) and 8mm, Olympus was making 8mm, but all of these have already been discontinued. Since digital cameras became the mainstream, there have been several fisheye converter lenses available for digital cameras. However, they are too small to fit to film cameras.

I wondered whether there is any fisheye converter lens that can be used for SLR cameras and my Rolleiflexes if possible. I searched the web for information, and there it is! That is the Fisheye Converter made by a Japanese manufacturer Kenko. When you attach the converter to your 50mm standard lens, you get a circular fisheye image. It has a mechanism adjusting the aperture according to the focal length of the main lens, and it can be used with TLR cameras. Although it is no longer made, I was able to find one easily at eBay, getting one for $50.

The official name is "Kenko Fisheye Conversion Lens." All metal construction, weight 250g. It has 9 elements in 6 groups so it is a pretty serious lens. It is accompanied by a screw-in adapter ring, which mediates the main lens and the converter (there were such adapter rings of different sizes - I own 49mm and 55mm ones). There is no problem with attaching the converter to Rolleiflex 3.5F, because I have a Bay 2 to 49mm step ring. You can also insert a filter between the main lens and the converter if you need.

The size of the circular image on film is determined by the focal length of the main lens. It seems that the converter works best with 50mm lenses for 35mm format (24mm x 36mm); with a 50mm lens, the diameter of the image circle is just a little smaller than 24mm. I had good results with a Carl Zeiss Planar 50mm F1.4. However, results were not good with a Yashica ML 55mm F1.2 - the image boundary is blurred, probably because the ML 55mm has a large front element and lights that would go through the peripheral area are cut off by the converter, resulting in the vignetting effect. This suggests that not all lenses work well with this converter (the instruction says that especially it does not work well with zoom lenses). Also, your camera's TTL (through-the-lens) metering will not show the correct exposure with the converter.

Using the converter with a TLR is pretty tedious. First, you have to put the converter on the viewing lens to determine the composition. Then you move the converter to the taking lens and shoot. You probably need a tripod because you don't want to change the location and direction of camera when you move the converter. A lens of focal length 75mm for the 6 x 6 format is equivalent to 40mm in the 35mm format. Thus, the image circle is a little too small relative to the entire image frame (the diameter of the circle is about 2/3 of the frame width) . Nevertheless, I like to have a circular image in a square frame.

I took pictures of my neighborhood with three different lenses. They were all shot at 1/125 sec. and f16 by CONTAX Aria and Kodak Portra 400NC film.

Carl Zeiss Planar 50/1.4 + Kenko Fisheye Conversion Lens



Yashica ML FISH-EYE 15/2.8



Carl Zeiss Distagon 25/2.8

The circular image produced by Kenko is characterized by low contrast and yellowish color. Resolution is also low, and the details get blurred as you go away from the center. It seems pretty vulnerable for against light, showing flare over the entire image and pentagon-shape ghosts around the trunk of the tree. It looks very classic in total. The second picture, Yashica is a diagonal fisheye. It produced such a great image with high contrast and resolution (maybe a little yellowish, though), though you also see a weakness of this lens here - a ghost around the trunk of the tree as well as the Kenko converter. The third picture was taken by a Distagon 25mm. Compared to the above two, it looks a little narrow even though the 25mm is wide-angle (my fault, I was too careless about the focusing for this picture - I didn't take much care of it because I was relying on that I was shooting at f16).