Zeiss Planar T* 85mm f/1.4 (Contax N to Canon EF) - Review / Test Report
Lens Reviews -
Canon EOS (APS-C)
Wednesday, 26 December 2007 10:38
Page 1 of 3
Lens kindly provided for testing purposes by Markus Stamm!
Some of you out there may still remember the old Contax systems. Back in 2000
Kyocera started a bold last attempt to rival the inevitable by releasing a brand new
AF SLR system - Contax N. The system found some friends but Kyocera abandoned the
market thanks to a disastrous execution and time-to-market of the Contax N Digital - a
6mp full format DSLR. You may think that this was the end of the story but that's
not totally true. Naturally Contax N lenses (designed by Zeiss) don't fit to
other system cameras but technically they are very related to Canon EF lenses - they
use an electronically controlled aperture mechanism as well as a build-in AF motor
(using either a conventional micro- or ultrasonic-motor). Obviously the lens control
logic is so similar that a smart fellow (Conurus)
reverse-engineered the data flows and created a "smart" Contax N to Canon EF adapter.
This adapter is not a plug'n play thing but actually a mount conversion. It's
not a cheap procedure either (350-750US$ depending on the specific Zeiss lens) but it can
revive these babies to behave like a native Canon EF lens - including a camera controlled
AF and aperture plus (mostly) valid EXIF data.
One of the supported lenses is the Carl-Zeiss Planar N T* 85mm f/1.4 - a classic Zeiss lens
although it is NOT identical to its recently released Zeiss ZF or Sony/Zeiss AF cousins.
The original symmetrical Planar design was invented in 1896(!) but naturally it has been
optimized over the decades and it is one of the most successful and most copied in the
business. "Planar" originates in the German word plan ("plane" in English) and refers
to the flat reproduction characteristic (minimal field curvature).
As usual we'll have a look how the T* 85mm f/1.4 on an APS-C DSLR.
I'm aware that some of you may have wished a test on a full format DSLR but
these tests will start based on the successor of the EOS 5D.
The 85mm f/1.4 is a beautifully crafted monster of a lens. You may notice that the EOS 350D
looks dwarfish in comparison. The lens requires huge 82mm filters so be prepared to
cry when investing into a polarizer. Thanks to an internal focusing (IF) mechanism
the physical length remains constant regardless of the focus distances. The very broad
rubberized focus ring operates smooth and accurate.
The T* 85mm f/1.4 features an ultrasonic AF motor. It's not a speed daemon
but reasonably fast and relatively accurate (the EOS 350D
tends to have troubles with ultra-large aperture lenses in general). Besides the
mount conversion Conurus faced one little obstacle - Contax N lenses have no
AF/MF switch (selected on the camera). However, he found a workaround for this: you
have to set the (otherwise useless) aperture ring to the smallest aperture for
manual focusing. This may be an unusual thought but it works just fine.
Interestingly the new firmware (v2.+) has a new "AF micro-adjustment" feature - similar
to the new EOS 1D III it is possibly to do a focus fine-tuning so if you're experiencing
a front/backfocus problem you can easily correct this yourself.
|Equiv. focal length||136 mm (full format equivalent)|
|Equiv. aperture||f/2.2 (full format equivalent, in terms of depth-of-field)|
|Optical construction||10 elements in 9 groups|
|Number of aperture blades||9|
|min. focus distance||0.83 m (max. magnification ratio 1:8.9)|
|Dimensions||90 x 80 mm|
|Filter size||82 mm (non-rotating)|
|Hood||metal, barrel shaped (snap-on)|