I prefer the 100mm Planar as a natural light lens. With a flash or strobes it loses some of its magic. I often shoot with fill-flash (a Canon 430EX on a Canon 1Ds Mark III) when traveling. Back home in front of the computer, the shots taken with a fill flash have a better exposure, but look flatter. The pictures without a fill-flash have more character. If I were buying a Contax 100mm F2 Planar and planned to use it just indoors for studio portraits and such, in that case I prefer the Canon 85mm L F1.2 or Canon 135mm L F2. Both of Canon L’s respond very nicely under studio strobes. There may also be some advantages in using a Canon EF lens when it comes to ETTL-II.

GETTING THAT 3D LOOK

One of the most common aspects of a 3D effect is typically a narrow DOF to isolate the subject from background - the foreground separates itself from background. The Canon 85mm L F1.2 (Mark I & II) and the Canon 135mm L F2 both do this very well, but the images seldom look 3D. In a recent conversation with Son Min Pham I asked his opinion why the Contax 100mm F2 Planar achieves the 3D look so often. Son said the there are two key lens characteristics needed excellent micro contrast and excellent chromatic aberration (CA) control.

Micro contrast is the subtle tonality apparent in gradients. It is these nuances in the shading which create richness and depth in the color tones. These shadings give objects a roundness and sense of depth. What Son added (which I never thought about before) is that the micro contrast must be excellent across the entire frame. Some lenses like the Canon 135mm L F2 have excellent micro contrast in then center region, but not at the edges. On a tightly cropped portrait, the 135L will have a nice look, but on broader compositions, it will not maintain the “pop” across the frame.

The second characteristic is excellent CA control. Any fringing around the outline of subject diminishes the edge sharpness. The loss of sharpness around the edge reduces the perceived separation from the background, thus the 3D effect is lessened  - or simply lost. The Canon 85mm L F1.2 is notorious for its CA at the wider apertures, the CA compromises the Canon 85mm L’s 3D abilities. Also, the Canon 85mm L F1.2 does not match the Contax 100mm Planar’s micro contrast levels.

ADAPTERS FOR CANON EF & EF-S BODIES

Aside from the metal fin on the Contax 100mm Planar’s mount, there are no other known adapter issues with this lens and Canon digital SLRs. The metal fin on the rear lens will prevent the lens from mounting on a Canon EF body. When mounting the lens and rotating it, the fin (may) strikes against the AF contacts and could potentially cause damage. Fortunately this is a very easy “fix” and just about anybody can perform the modification with patience and a steady hand. Using a Dremel tool with a sanding disk or cutting wheel, gently sand the fin down by ~1mm. The fin is ridged; one ridge should be enough. The fin does not have to removed, just reduced a little. The metal is very soft and the modification only takes a minute or two. Be sure to cover rear lens opening with painters tape or something similar to keep the metal shavings from falling into the lens. After the fin has been modified, a black Sharpie marker can be used to touch-up the brass metal.

The metal fin does not effect the 100mm Planar’s operation or performance. The metal fin is there to protect the aperture actuator when the lens is set down on a table without the rear lens attached. With fin shaved, the 100mm Planar will still work on Contax film body SLRs. After the fin has been reduced (or removed), do take care not damage or bend the aperture actuator.

In my experience the Cameraquest, Kindai and HappyPageHK adapters all worked fine and each reached infinity focus. I am currently using a Leitax adapter with the Dandelion chip. The AF confirmation adapters help with focusing, but it still takes a sharp eye to dial in critical focus. All the Canon focus points work, so off-axis compositions are simpler. The focus confirmation beep indicates the general area, but zeroing in on critical focus comes down to skill, practice and patience. When shooting at infinity, I like to use Live View.