Pancake lenses. Not many people use it nowadays, preferring the do-all zoom lenses. Going back to the old days when photographers would carry one prime lens per camera, and still be able to take amazing photographers, there is nothing a prime cannot do in the hands of someone with the right photographic vision. In short, nothing wrong with a pancake lens. In fact I love pancakes because it keeps the camera side profile smaller, making it possible to squeeze a pro-body with built in grip into a small bag. And most of the time you can zoom with your feet anyway.
A pancake lens is the name given to low profile lenses, normally around the 50mm focal length range. Up for this test are the two that I own. First up is a Nikkor 50mm f1.8 AIS. Now there are many versions of this lens, and the 0.60m minimum focal length version is the one I have, which is noticeably shorter than the other models. The other lens I have been using quite a bit is a Voigtlander 40mm f2 SL ULTRON. Yes a mouthful, I'll just call it AIS and ULTRON for the short version hereforth. They're both manual lenses. And they only meter on Nikon's semi pro bodies like the D300/D700 and up.
This is not meant to be a full on test, so I will not bother to perform an exhaustive test on it. On the question of bokeh, I have noticed that the ULTRON has this harsh donut shaped bokeh, perhaps because of the Aspherical element in the lens. But I'm not a bokeh freak so it is not an issue for me.
The ULTRON feels a lot better built than the AIS. The sample I have is the first version. Later Voigtlander came out with the SLII, which is almost the same except for the rubberized focus grooves. It has a nice well dampened focus feel to it, something missing in modern lenses. Don't be fooled by it. This is a modern lens. The aperture clicks has a nice feel to it, and the sure clicks in half stop marks from f2.8 all the way to f8 gives it just that bit more flexibility for those using aperture priority. Personally, I feel half clicks are quite useless in practice, but nice to have. Minimum aperture is f16. There are 9 aperture blades on the ULTRON.
AIS, however was a surprise when I first received my sample. I was expecting it to be a little bigger, but to my surprise it is the same length as the ULTRON. It is lighter though, and the construction doesn't seem as heavy duty as the ULTRON, but still a lot better than any modern consumer lens out there. The aperture ring on the AIS starts at f1.8 and goes all the way to f22 in full stop increments. No half stop here. Both lenses have depth of field marks and the AIS has infrared focus marking on it as well. Very useful for those that loves to take photo the old fashioned way. There are 7 aperture blades on the AIS.
And this is where pancake lenses really shine: mounted on a D2 body! Yeah baby!!
Center performance at infinity:
This test was done on a Nikkor D300, mounted on a Gitzo 1227 mkII tripod via an L plate from Kirk Enterprise. I would keep the focus at infinity and camera set to aperture priority while I turn the aperture ring on the lens.
I know the edges has to be tested as well, but it takes time and most of my shooting only makes use of the center. For landscape shooting, you would be crazy not to use f8-f11 range, and at that range, all lenses are fine edge to edge.
Looking at the AIS, wide open it has the same soft look on most prime lenses. The only prime I have that performs well wide open is the new Leica 50mm Summilux ASPH, but then again the price is also out of this world. Details are there on the AIS, but looks cloudy soft. Nothing to worry about there. Contrasts start to improve when stopped down, and f4 onwards the AIS starts to show what it can really do. Performance seems to peak at f4 or f5.6 and holds its own up to f11. From f16 onwards effect of diffraction starts to soften the image, but still usable of course! At f22, it fares worse than wide open.
On the ULTRON, performance across the aperture is not too different from one to another. The shot at f4 seems to be softer than f2.8 in my test, I would attribute that to a slight camera shake. This is a lens that I would not hesitate to use at all apertures. Sure, the performance at the peak is not as good as the AIS, which seems to render much better small details and better contrast. I used to bring the UTRON with me on the D2H, and mainly for the mechanical feel of Voigtlander's manual focus lens.
Comparing the two pancakes, the performance is definitely more than enough, though the AIS is able to squeeze out more detail at its sweetspot apertures above f4.
There is a more pancakey lens, the Nikkor 45mm f2.8P, which unfortunately I do not have at this moment. Have heard that it performs slightly better than the ULTRON, but it costs more. This would have to be a test for later then...
*end of post*