OVERVIEW

Finding fault with zooms is easy due to their optical compromises. From an optical standpoint the critics make valid points, but there is value in utility. Many times weather conditions make lens changes questionable - especially with dSLRs and the risk (or concern) of dusting land on the sensor. Other times traveling light is more important, and we want kits that can do more with less. And sometimes we venture into the unknown and have no idea what to expect - would normal prime be best, or a telephoto, or something wider?

The Contax 35-135mm Vario-Sonnar is a solid performing zoom. It is not particularly fantastic at anything specific, but it certainly is not a bad lens either. It is a well thought out lens with a useful zoom range on full-frame dSLRs. It will not replace a bag full of high quality primes, but the Contax 35-135mm zoom will do a fine job in good light. In my experience the 35-135mm macro function is the lens’ stand-out feature with very good performance. And the 135mm reach is very useful my shooting style.

This review (I use that term very loosely) was first published in 2007 and based on the Canon 1Ds Mark II. In May 2010 I decided to buy the lens again and give it another try on the Canon 1Ds Mark III. Since this review was first written, the Canon 24-105L F4 IS has been my benchmark lens for a walk-around, vacation type zoom lens. Revisiting the Contax 35-135mm Vario Sonnar some three years later has been an interesting experience.

HANDLING

The Contax 35-135mm Vario-Sonnar is a large lens. The size specifications listed on the Contax U.K. website list the weight at approximately 1.6 pounds; that is an error and the true weight is 2 pounds. The lens is about 5 inches long at 35mm, and about 7 inches when zoomed to 135mm. Like its twin brother the 28-85mm Vario-Sonnar, these are big lenses which feel front-heavy or nose-heavy when mounted on a Canon dSLR. The Canon 24-105L is a large lens as well and is a good reference point when trying to imagine the 35-135mm’s overall volume and weight. The 35-135mm’s diameter is rather beefy, similar to a Canon 70-200mm L F2.8. It is dubious to label the Contax 35-135mm as a “compact” walk-around lens. The Contax is great for that purpose, but it feels heavy as the day wears on, especially with a Canon 1Ds Mark III hanging off the end.

The Contax 35-135mm is a one-touch zoom - meaning the focus ring is also the zoom ring. The lens employs a push-pull design. Some photographers like this design because they can zoom and focus very quickly without moving their hand from one ring to another. Other photographers prefer the a separate zoom ring which turns opposed to the push-pull layout. The push-pull zoom design does move air volume, and some people fear this will to lead to dust being stirred up in the mirror box and eventually landing on the dSLR’s sensor. I have used the Canon 28-300L IS and 100-400L IS. The Contax 35-135’s pumping action is much more subdued in comparison and I do not worry about the Contax kicking up dust. Plus, with the dSLR dust shakers, dust is less of an issue today than 3 or 4 years ago. The push-pull action is very smooth, nicely dampened and the zoom stays put with no zoom creep.

Like all Contax RTS lenses the 35-135mm feels well built with a nicely dampened focus ring. The focus ring action is fairly light - it is a lighter action than my Contax 100mm F2 Planar. The focus ring feels very smooth and really is a joy to use. The only thing that seems bit awkward or kludgy is the secondary focus ring for the macro function. To engage the macro mode, the 35-135mm has to be in the 35mm. The secondary ring has to pulled backed and locks into position. The sliding action is not smooth and requires more force than I like. The macro mode is wonderful, but engaging and disengaging it is not so wonderful.

The Contax 35-135mm is rated F3.3 at 35mm and F4.5 at 135mm, but I suspect the lens has a much lower T-stop rating. When using the Canon 24-105L (an F4 lens) the viewfinder seems brighter than when using the Contax 35-135mm. At 135mm the viewfinder is quite dim and seems more like a F5.6 lens - and so the resulting shutter speeds. Focusing in dim light levels, such as the last couple hours of daylight, is challenging. The reason for this is two-fold. First, the dim viewfinder is - dim! Second, at F4.5 there is alot of DOF, so images do not “snap” into focus. I have difficult time determining critical focus. In the field things look well focused, but back at the computer the proof is in the pudding and there are more OOF’s than I care to admit to... If using a tripod and Live View, the keeper rate is good - but that sort of defeats the purpose of “walk-around” lens.