REVIEWS - Carl Zeiss Contax 100mm F2 Planar Telephoto Lens

OVERVIEW

It is easy to talk and rank lenses based on sharpness, but there is more to a good lens than sharpness - such as: contrast, coloring, distortion, light gathering, light fall off and bokeh (background blur). All these factors culminate into how a lens “draws” a scene. The 100mm Planar represents a nice balance of the these traits and easily transitions from shooting portraits to landscapes. Yes, the Contax 100mm F2 Planar is sharp, but that is a small part of what makes the Contax 100mm F2 Planar special. When talking about character, in my opinion the Contax 100mm F2 Planar trumps the well-known Canon 85L, Contax N 85mm F1.4 Planar and the Canon 135mm F2 L USM.

DUMB CONTAX LENSES

Keep in mind that the Contax AE and MM are fully manual lenses when used on a Canon dSLR or a mirrorless camera like a Sony A7rIII. Meaning, there is no electronic communication between the camera and lens, thus no automatic aperture or EXIF data about the lens. The same is true for any old manual SLR lens adapted to a modern camera via an adapter, but for people who have not used a manual SLR lens before (via adapter), this could be a bit of a surprise.

BUILD QUALITY

The Contax 100mm F2 Planar hails from the golden age of manual focus lenses. The lens barrel and mount are all metal - no plastic to be found anywhere. The manual focus action is very smooth and nicely dampened. The Contax 100mm Planar is a compact lens given its focal length and fast aperture, but it weighs 1.48 pounds, so it feels dense. On smaller dSLR or mirrorless camera, the balance might feel nose heavy. That said, the Contax 100mm is much smaller than the modern-day equivalent, the Zeiss Milvus 100mm F2 Makro-Planar ZE, which has become somewhat beastly over the years.

The entire rubber grip area is the focus ring, so finding the focus ring is a non issue. Depending on the condition of the lens, the focus ring might seem a little stiff depending on one’s expectations. The grease tends to stiffen over time - some of the AE versions are coming up on their 40th birthday. The aperture ring itself is easy find to by touch and it is fairly wide compared to a Leica R lens. While the aperture ring is close to the camera body, it is wide enough to not feel crowded or blocked by the camera body. The aperture ring clicks in full-stops, thus is easy to count-off without having to look directly at the aperture ring to see the selected value.

The front of the lens does not rotate while being focused, so there are no complications while using a polarizers or graduated filters. If staying true to the Contax ethos, the hood combination is a Contax 67-86 metal ring + Contax #4 metal hood. Aesthetically the ring and hood match the Contax 100mm's black paint and the rubber ring on the hood is the same as the rubber used on the focus and aperture rings. The screw-in hood design is great for polarizers and graduated filters - screw those in and then the hood. To rotate the polarizer (or grad), just rotate the hood - very convenient in use vs taking a lens hood on and off.

The Contax 100mm has a very solid feel and it feels even better with a Leitax adapter. The Leitax adapters are screwed to the lens re-using the original Contax screws. The result is no wiggle or play between the lens and adapter. The Leitax adapters also mount and dismount from the Canon camera body very smoothly too. All in all, a very OEM feel. There are cheaper adapter alternatives, but I prefer the Leitax option.

LENS PERFORMANCE

Some key stand out areas are the Planar’s micro-contrast, its depth of field (DOF) and overall flexibility. The 100mm Planar’s micro-contrast translates into detailed textures, such as in distant tree foliage. Compared to Canon L lenses, the 100mm Planar produces subtler gradients and shows more detail. Where the Canon lenses tend to rush to deep blacks (often burying details in crushed shadows), the 100mm Planar opens up the shows and mid-tones, revealing nuances in the shadows. In general the Planar has a gentler roll-off in shadows.

Another difference between the 100mm Planar and its Canon counterparts is how the Contax 100mm renders DOF. DOF is a standard calculation, but in practice the perceived DOF is influenced by how the lens eases in and out of the plane of focus and by the circle of confusion. On-line DOF calculators estimate the DOF for given focal length, aperture and distance. This can be misleading because it suggests that all 100mm lenses will perform in the same manner. This is not the case. For example, we have seen how bokeh can differ from Leica 50mm lens to Canon 50mm lens to Zeiss 50mm lens - such as "busy" bokeh vs a more gaussian bokeh. The 100mm Planar’s transitions quickly in and out of the plane of focus, kind of like a pulse wave. I associate Planar designs with this quick transition, whereas Sonnar designs have a more gradual transition.

So what does this mean? The Contax 100mm Planar is very good at separating the subject from the background, even at modest apertures like F5.6. While some people do not care for "Zeiss bokeh", like it or not, the 100mm Planar produces an abundance of it. Also, the quick transition from bokeh blur to in-focus contributes to the 3D feel in the images.

With regards to the AE vs MM versions, generally my MM versions have been a bit sharper at F2. I am unsure, but suspect the older AE versions are made with leaded glass, and the contrast in their bokeh seemed a bit denser. That is a very nuanced comparison, and frankly the difference could be more about age and condition versus actual deltas in glass composition.

CONCLUSION

The Contax 100mm Planar has a unique signature that is not easy to match with other lenses. The Contax 100mm Planar is a well liked lens and most people are very pleased with its optical performance. The decision is not so much about whether the Contax 100mm F2 Planar is “good” or “bad” lens. The decision really is whether or not stop-down metering and adapters are an acceptable solution. When things are moving quickly, opening the lens to F2, focusing, composing, focusing, adjusting metering, focusing again - and then having to stop down to F4 or F5.6 can mean missing the shot. Though, with today's mirrorless camera options, using the Contax 100mm today is much easier vs in past years with traditional dSLRs and their optical viewfinders.

I really enjoy the Contax 100mm Planar and have yet to find another lens that matches how it renders a scene. The Zeiss 100mm F2 Makro-Planar ZE is a close match, but there are some subtle differences in the renderings (review here). To be fair, I think the Zeiss 100mm F2 Makro-Planar ZE is a better studio lens when shooting with mono-lights, etc. And of course there is the legendary Hasselblad 110mm F2 Planar from the Hasselblad medium format V system (review here). It really is hard to make a bad choice here - all the Zeiss 100mm Planars are wonderful. Ultimately you just have to try one and see if the "look" is right for you.