REVIEWS - Contax N 100mm F2.8 Sonnar-Makro Lens

OVERVIEW

Bo-ming Tong of Conurus Imaging Corporation pioneered the Contax to Canon EF conversion process, thus giving Contax N lenses a new lease on life. Conurus’ conversion is a full-fledge electronic modification which turns the Contax N auto-focus lens with auto aperture into a Canon EF auto focus lens. Once converted, the Contax N lens operates like any other Canon EF lens on a Canon dSLR.

The conversion includes replacing the mount with a custom machined Canon EF mount, loading custom firmware and modifying some electronics. The lens firmware is upgradable (via Conurus). Focus is calibrated and Bo-ming incorporated a micro focus adjustment feature in later firmware revisions, allowing end-users to adjust the lens to their camera. Bo-ming’s craftsmanship and attention to detail is superb.

BUILD QUALITY AND LENS HANDLING

The lens is all metal and the finish seems durable as most Contax N lenses age well (no paint peeling). Being a 1:1 macro lens, the Contax 100mm N is on the larger side. All the mechanics are internal, so the lens stays a constant size throughout the focus range. Auto focus is slow, but accurate. Auto focus is not as quiet as a Canon USM auto-focus lens. There is no AF / MF switch on the lens barrel, but with the lens aperture ring set to F22, auto focus is turned off - a unique feature of Conurus’ custom firmware. Also, the custom firmware adds the ability to set the aperture 1/3 stop increments. The original Contax 100N lens steps in 1-stop increments

LENS PERFORMANCE

While testing the Contax 100N, what I noticed most was its color palette and smooth graduations. Normally the Carl Zeiss T* multi-coatings are characterized as producing cooler colors than Canon lenses. I think the “cooler colors” statement is generally true, and perhaps more faithful to the actual scene. Canon’s greens and reds tend to be over-saturated. Sometimes the Canon color palette works, such as for sunsets, but not so much for portraits. On Canon lenses the purplish magentas tends towards a red, whereas here the Contax 100N produced a wonderful array of subdued purples and magentas.

While some of the outdoor images exhibit double image bokeh, overall the bokeh is probably my favorite aspect of the Contax 100N. While not best general use, the bokeh works very nicely for product photography. The ingress and egress to the DOF is quite long, so neighboring objects are recognizable, but still nicely blurred. If photographing an ensemble of objects and wanting background objects blurred (but still recognizable) the Contax 100N is excellent. It is a subtle nuance, but the look is distinctive. Also, I feel the Contax 100N is capable of going head-to-head with medium format in terms of the elusive 3D look.

CONCLUSION

The Contax 100N is a macro lens first and foremost. In that realm it excels and if trying to produce distinctive product shots, the Contax 100N definitely deserves consideration. If looking a true macro lens, I give the Contax 100N a big thumbs-up, and I like the Contax 100N much more than the Canon 100mm F2.8 L IS. As a portrait or landscape lens, I suggest the Zeiss 100mm F2 Makro-Planar ZE, Contax 100mm F2 Planar or Canon 135mm F2 L. This review was first published ~2009. Fast forward to 2017 / 2018 and Contax N lenses can be easily adapted to the Sony E / FE mount with no need of modification or conversion. My opinion of the lens is unchanged, but I would opt to use this lens on a Sony camera today vs going through a Conurus modification. I think Conurus has stopped performing conversions anyways.