T* optics on Canon DSLR cameras, dream? truth?
of the test: to see if the Zeiss lenses were performing
good on a digital camera, at least as good as a good zoom lens,
and to realize if it is worth (for me) to buy a Canon dSLR with
the idea of keeping it as digital body for the Contax system.
I've got a Contax slr, manual focus35mm system, that is the final
solution of all my ancient speculations about usability, quality,
and response to my specific needs. Now I need to go digital, for
professional purpose, and my desire would be to keep my trusted
and loved superb quality pieces of glass. But I also use and work,
even digitally, with some Nikon lens, included the 8mm 2.8 AI Fisheye-Nikkor.
I've experience in self building photographic hardware, and looking
to the registry table of SLR systems, is clear EOS bayonet have
the space to accomodate many other manufecturers' lenses, such as
Olympus, Nikon, Contax, Leica R... without glass elements, allowing
focus to infinite.
A symple ring allowing to mount other systems' lenses on an EOS
digital reflex body,allowing focus to infinite... Yes, and more
out of market, the only other conversion ring serious manufacturer
is Novoflex. They offer high quality solutions for Nikon and Leica
lenses on EOS.
Two years ago I discovered, in a georgous mine of informations as
well as beautyful site, cameraquest,
a reference to a Yashica/Contax adaptor on EOS camera, here.
It looks like to be VERY well machined etcetera, but a little pricy
for my testing purposes. They also sell the widest range of adapter
ever. However I can't speak of anything I have not tested, so I'll
pass on. Also Fotodiox is offering a pro-version of this adapter,
having experienced their Nikon adapter quality I think I'll buy
one as soon as I've the money.
Obviously I looked forward a cheap source on eBay. I waited and
found many. I have access to many DSLR cameras, so the only thing
needed was the ring. I found many...
Contax/EOS adapter ring, no retain version.
the C/Y to EOS adapter, you can see the red
C/Y lens coupling mark
from left to right: the EOS red coupling dot,
the EOS lens locking hole and on the bayonet the useful stop screw,
avoiding any damage if you twist the wrong side,
retain or not?
When you mount a bayonet lens on your camera, you insert
it and rotate till a familiar "click", than there is a
button to release the lens. An adaptor, like a macro tube or a focal
multiplyer, has to safelu click onto the camera as well onto the
lens. You need the space, between lens and camera, to mount a retain
system and a release button.
In case of Nikon and Leica adapters, no problem. For Contax lenses
you can find the two versions...
Lens retain version
Since the space is poor, the lens retain version has no external
release button. You mount the adapter on the lens, than you mount
the lens on the camera.
Than you unmount the lens+adapter, and the adapter from the lens.
No retain version
In this case you can leave the ring on the camera, and
unmount/mount the Zeiss lenses as you like. A flat spring in the
inside of the bayonet, ensures a little strenght of retention. the
lens needs to be tighten a bit, and you can focus or change apertures
without unmounting the lens.
Does this work on all lenses? Well... my 28mm f2.0 fits a little
bit loosy, as my 35 2.8 and a 50 1.7 MM. not enough to cause misalignment,
but enough to take care not to unmount the lens while focusing!
But a little screw allow to fine tune the spring.
It works. You can use it with some limitations:
All is ok, but if you are used to have a stigmometer for correct
focusing be aware. In the flat, clean field you will have neither
the digital telemeter to help you! The 300d and the 350XT, "digital
rebels" do not have a prism finder, but feature a mirror prism,
so focusing begins to be complicated.
infinity: Infinity focus is guaranteed... but precision
machinery is a costy thing. So they allow some tolerances, but they
consider a thinner flange-to-flange adaption, that has the consequence
that it allow your lens to focus OVER infinity. You will
never notice it if you do not usa a very wide lens: wides focus
moving all optical elements of a very short distance, souch short
that a 0.1 mm error can lead to misfocus. With fisheyes the thing
becomes critical, and you NEED a PRO adapter ring.
It is stop-down mode. For me is the natural way of taking pictures.
For someone else is not. However, EOS cameras can meter both in
Aperture Priority and Manual mode.
exposition roblems were found with 1.4 lenses, 50 and 85mm have
the tendence to overexpose of 1,6/2 stops. No try was done with
a 35mm 1.4 Distagon.
| pictures of the
lock release adaptor here.
It was a test without any real scientific purpose: it involved a
300D, a 20D, a D1s mark2, as lenses it involved some of the most
beautyful Contax ones (18 to 85) and 2 completely different Canon
zooms, the 18-55 bundled with the 300D, a body-cap just grinded
out of a Coke bottle... but surely not from a glass one, and the
famous 24-70 f2.8, just taken out from the shelf. Some interior
shot, on a tripod, some shot on the field.
My final reply to the mai question is YES, I'll use my Contax lenses
on Canon body. I can see no vignetting or aberration caused by light
rays not being parallel to sensor, nothing in the 1.6x cameras nor
in the 1x D1s markII, that shure has some workaroud for this issue,
onboard. The expensive 24-70 is performing surprisingly good, even
if is behind (for my taste) my Contax lenses.
On the opposite, the 18-55 given with the camera is so bad that
a good consumer Powershot-A95 gives a far better result. Acceptable
at 18, BAD at 55. It is a 100eur lens, in fact. Not more, not less...
to be so cheap it is not so bad at the end.
Contax 45mm Tessar f2.8 on EOS 350D/Rebel-XT
here for the
original jpg (2,5Mb!!!)
- EOS 300D /
- EOS 350D /
digital Rebel XT*
- EOS 20D
- EOS 10D
- EOS D1s MKII
my own camera.
Carl Zeiss T* Contax/Yashica bayonet
25mm f2.8: excellent
28mm f2.0: a bit loose on the adapter
28mm f2.8: excellent.
35mm f2.8: a bit loose on the adapter
45mm f2.8: excellent, ultralight, ultrasmall
50mm f1.7: excellent
50mm f1.4: overexposed metering
85mm f1.4: overexposed metering
135mm f2.8: excellent.
macro Yashica ML: excellent
200mm f2.8Angenieux 200mm f2.8: excellent