OVERVIEW

The Contax C/Y 100mm F2.0 Planar is my favorite telephoto lens for the Canon EF dSLR system. In my opinion the Contax 100mm F2.0 Planar trumps the well-known Canon 85L (both the original and new Mark II version), Contax N 85mm F1.4 Planar and the Canon EF 135mm L F2. It is easy to talk about sharpness and rank lenses solely on their resolving capabilities, but there is more to a good lens than sharpness. Other important considerations are contrast, coloring, distortion, light gathering, light fall off, bokeh (background blur), etc. All these factor culminate into how a lens “draws” a scene. The 100mm Planar represents a nice balance of the above traits and can easily transition from shooting portraits to outdoor  landscapes. So yes, the Contax 100mm F2 Planar is sharp, but that is such a small part of what makes the 100mm F2 Planar special. The Contax 100mm has distinct character which gives its picture an extra nuance not found with Canon EF L primes.

I have owned three different Contax 100mm F2.0 Planars and all were excellent. Being an older lens there will be good and bad copies depending on how well the previous owner(s) cared for them. Optically I did not see any significant differences between the AE vs MM variants; however, Zeiss no longer services AE lenses, so I would suggest paying a bit more and finding a newer MM version. I purchased my current 100mm Planar from KEH as a LN- (Like New Minus) and the lens looks & operates like new. Expect to budget $700 to $1100 (USD) for a Contax 100mm Planar. Add in the adapter, metal lens hood (67-86 Ring + Metal Hood #4) and the K-84 metal lens cap, and the total price can be expensive. If buying a used lens troubles you, then there are the new Zeiss ZF lenses (also available in Pentax, Sony and M42 mounts). These new Zeiss lenses offer the classic performance - but are new. There are some differences - the new Zeiss lenses are new optical designs, not re-issues of the original Contax designs. (Update - Zeiss 50mm F2 Makro-Planar ZF review available)

AE, MM OR ZF?

I have tried the Contax 100mm F2 Planar AE, 100mm F2 Planar MM and Zeiss 100mm F2 Makro-Planar ZF all side-by-side on a Canon 1Ds Mark III. Technically, since all three are being mounted on a Canon EF mount via adapter, there is no mechanical advantage of one of the other. All three lenses are “dumb” lenses on the Canon body, meaning there is no electronic aperture and each lens is manual focus. Optically, I found the ZF to be the sharpest wide open with slightly cooler colors. The MM was nearly identical to the ZF, maybe a tiny bit soft (say 5% softer?) wide open - but it was such a small difference that I would not worry about it. The AE versions was the softest of the group and its coloring was softer, not as bold as the ZF. There is about a 30 year ago difference between the AE and ZF, so the difference in coloring is surely a function of updated lens coatings. At F5.6 all three lenses were indistinguishable when comparing sharpness and contrast. The AE version had the lightest focus ring by far. One upside to the ZF is its macro abilities, but it is a larger, heavier lens than its 100mm Planar predecessors. Personally, I prefer the Contax versions over the ZF because the ZF has a very poorly placed / designed aperture ring which makes stop down metering difficult at best. When Zeiss adds a 100mm F2 Makro-Planar ZE to its line-up, I will purchase it. I look forward to having an automatic aperture.

LENS PERFORMANCE

Some key stand out areas are the Planar’s micro-contrast, its depth of field (DOF) and overall flexibility. In the case of the 100mm Planar the micro-contrast results in better gradients and more detailed textures. Compared to Canon L lenses such as the EF 135mm L F2 and EF 85mm L F1.2 (Mark I and II), the 100mm Planar produces subtler gradients and shows more detail. Where the Canon lenses tend to rush to deep blacks (courtesy of Canon’s exaggerated macro contrast), the 100mm Planar holds more mid-tones and captures more detail in the shadows. In general the Planar has a gentler roll-off. Another key difference between the 100mm Planar and its Canon counterparts is DOF. The 100mm Planar has proven to have a thinner DOF than the Canon 135mm L F2 when shot at equal apertures. Test shots were taken at the same distance and at the same aperture. According to the DOF tables the 100mm Planar should have more DOF; however, it proved to have 1 to 2 stops less DOF than the Canon 135L.

Keep in mind that DOF is not a standardized metric. A Leica 100mm F2.8 Elmarit-R Macro APO, a Contax 100mm F2 Planar, a Canon EF 100mm F2, etc., will all have a different DOF at F4. The resulting DOF is a function of the lens design. On-line DOF calculators at various websites ESTIMATE the DOF for given focal length, aperture and distance. This can be misleading because the user thinks all 100mm lenses will perform in the same manner, and that’s simply not the truth. There are also dramatic differences in how various lenses in and out of the DOF.