Adapters for alternative lenses
Why?
There are many reasons why to use alternative lenses. Some use them because they have them from their
old system. Some use for cheap price. And some use because of characteristics Carl Zeiss and Leica can offer.
I use alternative lenses mainly for the characteristics and Canon's lack of capability to buid good wide angle
lenses (I don't even need ultrawide...). Some of the Canon lenses have some characteristics, for example Canon EF85 f/1.2L USM Mark II or Canon EF135
f/2.0 L USM. However even these very fine Canon lenses lack some characteristics which I prefer, like
good micro-contrast over whole frame or lack of chromatic aberrations.
How it's possible
Canon EOS system has one of the shortest distances from lens mount to the film/sensor. Therefore it's possible
to create adapters which will come between the lens and Canon EOS camera body. There are no optical elements, and
the picture quality is as good as it is with the original camera into which the lens was designed for.
I have adapters for Nikon F mount, Contax/Yashica mount and Leica R mount. Below is picture of them and they are in same order which I listed them:
There are adapters for other systems as well, like Olympus and M42.
Some lenses cannot be used in Canon EOS even there is adapter available. Reasons can be protruding things to mirror
chamber and lens not having manual control for aperture (e.g. Nikon 14-24mm which many people would like to use
in fullframe Canons).
How adapters are used
Since there is no electronical connection between lens autofocus and automatic stopping down of lens is lost.
Therefore alternative lenses are not for mainstream. Also due to implementation of exposure metering of
non-professional even exposure is not metered correctly when lenses are stopped down. I have listed below two
procedures how I have used the lens.
Procedure with non-professional camera (20D, 40D, 5D etc.):
1. Set camera to M-mode
2. With lens wide open manual focus and measure exposure
3. Close down the lens to aperture you want to use
4. Calculate exposure at closed aperture from wide open measurement
5. Take photo
Procedure with professional camera (1D series):
1. Set camera to Av
2. With lens wide open manually focus
3. Close down the lens to aperture you want to use
4. Take photo
Adapter quality
Adapters can have many kind of quality problems. At least following can be problematic:
- adapter flatness (may result for example left side being less sharp than right side)
- adapter flare (better adapters are painted back from the part which is exposed to camera sensor)
- bad tolerances (adapter may not fit or is too loose to lens)
Fotodiox C/Y adapter bad quality
Even photodiox is supposed to be best of the adapters I wasn't very happy to their product. There was some play
between the adapter and the lens. When lens was attached to adapter and adapter to camera I can move the lens
about 0.5mm to up, down, left or right (in same plane as lens mount). Therefore I ordered cheap eBay adapter
but problem with it was too thick and lenses could not focus to infinity. Therefore I needed to adjust the focus of
my only C/Y lens Carl Zeiss Distagon T* 28mm f/2.8 to match the adapter.
Adjusting focus on some Carl Zeiss lenses
Lenses which focus by moving all the class front and back the correct position of infinity can be adjusted
even with slightly too thick adapter. Here is how you can adjust it:
1. Remove the front part of the lens by turning it to anti-clockwise (it has threads, at least on CZ 28/2.8)
2. Adjust focus to infinity
3. Remove the four skrews which are available after the front of the lens has been removed
4. Move the focusing ring from infinity to 2m meters
5. Close the four skrews
6. Test and re-adjust if needed by repeating steps 2-6 and using your brains...
Pebble Place - C/Y adapters
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