The Contax 35-135mm is a long lens, thus the incoming light has to travel down the full length of the barrel. The one-of-the-focal-length rule for the shutter speed does not work well. Even at 35mm I suggest keep the shutter speeds at 1/200th or faster - which is difficult with a slow aperture lens that does not gather light very well. Plus, the lens is heavy, so lens and camera shake is another factor to take into consideration. When I first reviewed the lens in 2007 with the Canon 1Ds Mark II, shutter speeds were a real issue. But today (2010) with the Canon 1Ds Mark III and its good high ISO performance, upper ISO performance is better and the Contax 35-135mm benefits.

LENS PERFORMANCE

Across its entire focal range the Contax 35-135mm is a solid performer. The 35mm side has nice resolution, distortion is well controlled and the images have the typical Zeiss coloring. The corners are pretty good. At F8 the corners are sharp, but the resolution is lower than the center of the lens. Images have a nicely balanced contrast with good shadow detail. There is some barrel distortion which corrects easily is most raw editors. I have not noticed any complex wave distortions like those found in the Contax 21mm Distagon. The wide open rendering at 35mm is pleasing to my eye. At 35mm I feel the resolution is as good or better than the Canon 24-105L at 35mm. The Contax probably has higher resolution, but the corners on the Canon 24-105L are better (assuming a F8 image).

The 135mm side is a bit more exciting as the 135mm focal length does offer nice bokeh for portraits and such. Compared to the Canon 24-105L, the Contax 135mm reach offers more background blurring potential. However, do not carried away - this lens is NOT a Canon 135L. At 135mm the aperture feels more a F5.6 lens than a F4.5 lens. Bokeh is pleasant in most conditions. Busy backgrounds such as pebbles, rock beds or foliage can create some undesired effects. This true for most lenses, so this is not a demerit solely against the Contax 35-135mm - just something to be aware of when shooting 135mm. The Contax 35-135mm can render a pleasing portrait, but for portraits and similar subjects, I much rather use the Contax 100mm F2 Planar.

There is some light fall-off in the corners - probably in the 1 to 2 stop range when shot wide open. This degree of fall is typical for most zoom lenses. When stopped to down to F5.6 or F8, any light fall off that remains is not noticeable. There can be some strong vignetting in macro mode in the extreme corners - expect to crop the last 2-3% of the image in each corner.

Zeiss lenses are known for their 3D pop. The Contax 35-135’s does not produce much 3D feel. The images have nice contrast and sharpness, but there is not that “jump off the page” feel in terms of depth or roundness. I have seen some hints of 3D, but nothing that makes me say “wow!” Coloring is neutral. Pictures tend to have nice greens and blues, but again, the colors are not high contrast with eye popping “wow”. Post processing can add that wow (for color) if desired. The first three images on this page were NOT color edited.

Coloring fringing (CA) is evident, but is minor and tends to be less than the Canon 24-105L. What bit of CA that does show up, is easily eliminated in Phase One C1 Pro. The lens will flare if shot into the sun. The flare has been the pretty type with nicely stacked shapes & colors. I have not experienced any ugly flare spots that look like a burnt tear drop. The front element does NOT rotate, so using polarizers and graduated filters is trouble-free.

MACRO MODE

The Contax 35-135mm’s macro function is amazing and the most impressive feature of the lens. The Contax 35-70mm Vario has a simple macro function which engages when the focus is turned fully to the left and past a soft-stop. The 35-70mm’s macro function is a neat parlor trick; whereas the 35-135mm is a serious macro lens. To engage the macro function on the 35-135mm, the focus ring is set at 35mm, then the lower ring is pulled towards the camera until the secondary ring locks into position. As mentioned earlier, engaging the macro mode is somewhat awkward, so do not be surprised if it takes more force than expected.

Once in the macro mode the the focal length has a small zoom range - probably in the 35-45mm range. Yes, you read correctly - a ZOOM range in macro. The secondary ring (the one used to engage macro mode) is also the focus ring for the macro mode. The big focus ring controls the zoom by rotating the ring. The minimum focus distance is ~12”, but I think Zeiss measures this from the rear element.

The Contax 35-70mm macro mode is nice, the Contax 35-135mm macro mode is much more refined - the adjustability and range is greater, with more precision. I used the zoom for a number of product shots because its macro view had a very unique, somewhat wide angle feel. The light fall off in the corners can be pretty high on full-frame dSLRs, so shooting F8 or F11 is a good plan. At times there can even be some vignetting in the extreme corners.

OVERALL IMPRESSIONS

There are two basic swiss army knives. There is little one with two blades and the slide out tooth pick and tweezers. Many companies use these as giveaways at trade shows, etc. Then there are mega versions with 20 different fold out blades and tools. Knife stores will often have these in their display window with jumbo sized mechanized one with the blades automatically opening and closing. Do you need all those blades and gizmos? No. After all, who wants to carry that brick in their pocket? But if you find yourself on a deserted desert island, you’ll sure as heck wish you had 1 pound mega knife. The Contax 35-135mm is that mega swiss army knife.