The Contax 35-70m f3.4 is a somewhat unknown yet fantastic lens. It's not especially fast, or of a wide range, but it's results are nothing short of exceptional.  According to photodo's tests, it's equal or sharper than any Canon lens within it's range.  Even including L primes!  Contax's brochure claims the same thing. Sounds crazy? Yep, but it's true.

Here is part #1 of the Contax 35-70mm lens test pitting it against a diverse gang of glass from the inexpensive to the highly regarded:

Sigma 30mm f1.4 This lens is fast and very sharp in the middle even wide open. It has quite a bit of barrel distortion, so it's not a great architectural lens.  Where it shines is with low light level portraiture.  Nice bokeh, sharp centers, fast focus and that sexy f1.4 make this a superb street and available light portrait lens.

Canon EF 50mm f1.8 'plastic fantastic'  This lens is cheap.  It's like $80 brand new. Don't expect it to run with boutique glass, but it's still a lens i highly recommend 

Canon EF-S 60mm Macro  This is one of the best lenses Canon has ever made.  Really. It's overlooked due to the EF-S mount, but tests don't lie, this thing is killer

Canon EF 28-135mm IS  Some people love this lens.  I've had two, returning the first one due to lackluster performance.  It didn't test overly well (another bunk copy?) and it's clear that it does a better job on the long side vs the wide end.

Canon EF 70-200 f4L   Simply, one of Canon's best lens values available.  Sharp wide open, compact, fantastic contrast, a fine representative of the 'L' moniker.  There's now an IS version which is a fair bit more expensive.

How did it go?  On this test, the Contax won. There were a few close calls and a tie, but overall the CZ 35-70mm lives up to its reputation

When you consider a street/ebay price of $300-$400 and a very impressive macro function, you simply cannot loose.

Photodo, a few other sites and my tests confirm that this lens is at it's peak performance from f5.6 onwards. I shoot at f5.6 mostly unless the DOF is needed, and notice slight diffraction effects starting to come in at f11-f16.


Here's the test scene, lovely Vancouver shot from Main and Broadway. The red squares are the crop areas.
This test won't reveal too much about chromatic aberrations, or bokeh. That's upcoming test #2



35mm center crop  (click for full size)

The Contax is decent wide open, and excellent at f/5.6
The Sigma is SHARP in the center, even wide open. Fantastic!
The Canon 28-135 is decent in the center at all apertures, and oddly a bit worse stopped down. This is also noticable in the bottom corner test. This is my second 28-135, the first one a poor performer. This one is better, yet isn't that impressive.

Winner: Tie? Contax by a hair?

35mm lower right (click for full size)

The Contax 35-70 is good wide open and excellent at f/5.6
The Sigma is moderate wide open (pretty good for f/1.4 really) and improves a little by f/5.6
More 28-135 weirdness.. It's sharper than the Upper right sample, and actually is better wide open then at f/5.6. I triple checked this - very surprised myself - but the EXIF doesn't lie.. it's quite good in the bottom corner wide open and degrades a little by f/5.6. As mentioned, this is my second brand new 28-135mm....

Winner: Contax Zeiss


35mm upper right (click for full size)

The Contax 35-70 is good in the corners wide open and excellent at f/5.6
The Sigma doesn't do too badly wide open in the corners - remember f/1.4 - improving to acceptable at f/5.6. I would imagine the Sigma gets a lot better around f/8 or f/11. The sample areas are different for the Sigma because it's 5mm wider than the other lenses. I think i have a good copy of the Sigma 30mm, seeing worse on other review sites.
The Canon 28-135 has issues. I bought one, it was bad and returned it, got a new one, this is it. What's a guy to do?

Winner: Contax Zeiss


50mm center crop (click for full size)

Contax 35-70 is a little soft wide open, becoming fantastic at f/5.6
Canon 50mm f/1.8 is pretty nasty wide open, decent at f/3.5 and good at f/5.6. The Contax is noticeably better.
Canon 28-135mm suddenly arrives! Not bad at 50mm at all

Winner: Contax Zeiss


50mm lower right (click for full size)

Contax 35-70 is ok wide open and excellent at f/5.6
Canon 50mm f/1.4 is nasty wide open and excellent at f/5.6
Canon 28-135mm is good wide open, becoming a little better by f/5.6

Winner: Contax Zeiss



50mm upper right (click for full size)

Contax 35-70mm is good in the corners wide open and excellent at f/5.6
Canon 50mm f/1.8 is pretty bad in the corners and improves to very good by f/5.6. The Contax is slightly better.
Canon 28-135 isn't that great in the corners and stopping down doesn't help much, since it's only one stop

Winner: Contax Zeiss


60mm center crop (click for full size)

Contax 35-70mm decent wide open, becoming good at f/5.6
Canon EF-S 60mm macro good wide open becoming excellent at f/5.6. This is one of my best lenses. There's slight vignetting wide open, but once stopped down, it's incredible.
Canon 28-135mm Stupidly, i misplaced my 60mm images from this lens. Sorry.

Winner: Canon 60mm EF-S Macro by a hair


60mm center crop (click for full size)

Contax 35-70mm decent wide open, becoming good at f/5.6
Canon EF-S 60mm macro good wide open becoming excellent at f/5.6. This is one of my best lenses. There's slight vignetting wide open, but once stopped down, it's incredible.
Canon 28-135mm Stupidly, i misplaced my 60mm images from this lens. Sorry.

Winner: Canon 60mm EF-S Macro by a hair. According to Canon's MTF charts, this is one of Canon's best lenses ever made, only bested by the discontinued (and boy do i want one) 200 f1.8L, the 300mm f2.8L. This is one of Canon's best kept secrets, which has remained under the radar because of its EF-S mount...


60mm lower right (click for full size)

Contax 35-70mm good quality wide open becoming excellent at f/5.6
Canon 60mm EF-S macro Good wide open, improving by f/5.6 I feel the Contax is a little sharper and has more contrast.
Canon 28-135 i misplaced these images so they're unavailable in this test. Sorry

Winner: Contax Zeiss. The 60mm EF-S is close.


60mm upper right (click for full size)

Contax 35-70mm is decent wide open, becoming excellent at f/5.6. Note how clear it looks.
Canon 60mm EF-S macro is good wide open, improving by f/5.6. I feel the Contax is sharper and has noticeably more contrast.

Winner: Contax Zeiss



70mm center crop (click for full size)

Contax 35-70 Good wide open, and excellent stopped down
Canon 70-200 f/4L Excellent wide open marginally better stopped down? Fantastic wide open performance!
Canon 28-135 Decent wide open and good by f/5.6. A comeback performance from the 28-135mm

Winner: Contax 35-70, although the 70-200mm f/4L is very close



70mm lower right (click for full size)

Contax 35-70 good wide open, excellent at f/5.6
Canon 70-200 f/4L Excellent wide open, slightly better at f/5.6
Canon 28-135 Moderate wide open and good by f/5.6

Winner: Tie? The Contax and the Canon 70-200 f/4L are very close.. Slight advantage to the Contax?



70mm upper right (click for full size)

Contax 35-70 good wide open, some slight CA, improving to excellent at f/5.6
Canon 70-200 f/4L Excellent wide open and slightly better at f/5.6
Canon 28-135 Poor wide open and just slightly better at f/5.6. Weird how the lower right was so much better.. some elements must be misaligned.

Winner: Contax Zeiss