Michael J Davis <(E-Mail Removed)> wrote:
>John <(E-Mail Removed)> was inspired to say
>>
>>"Michael J Davis" <(E-Mail Removed)> wrote in message
>>news:(E-Mail Removed).. .
>>> John <(E-Mail Removed)> was inspired to say
>>>>I bought an adaptor on ebay so I could use my Minolta lens's on my Canon
>>>>camera. Works great in aperture priority mode.
>>>>
>>>>My 50mm 1.2 became somewhere between a 50mm 1.4 and a 1.5.
>>>
>>> Eh?
>>>
>>You loose a bit though the adaptor. The images come out a little bit darker.
>>I open up 1 stop to compensate.
>
>You mean the adaptor has *glass* in it? (i.e. like a telephoto
>adaptor.)
>
>Otherwise the light collecting ability of the lens is the same
>regardless of the camera used.
>
>If the images come out darker, it's more likely to be sensitivity /
>calibration differences between the cameras. IMHO of course.
The adaptor has to have a glass element in it otherwise it would be
impossible to obtain anywhere near infinity focus. The lens would be
good for macro work only.
That's because of the difference in register between Minolta MD and
Canon EF lenses. Canon EF has one of the shorter registers, which is
why you can fit so many different types of lenses to it with an adapter.
For example, I use Contax/Yashica, Nikon AIS and AF, Pentax K and M42
mount lenses on my Canon 5D bodies. They all give correct infinity
focus, and none of the adapters needs a glass element.
Not only do adapters with a glass element reduce the light coming
through the lens, but they make the focal length longer, typically by a
factor of 1.2 or 1.3. What is worse is that they significantly degrade
image quality; the effect is far worse than an average teleconverter.
So using Minolta MD lenses on a Canon EOS body would be pretty
pointless.
On the other hand, the MD mount's short register would not prevent an
adapter being manufactured to fit them to a Four Thirds DSLR, let along
the Micro Four Thirds Panasonic G1 which has an even shorter register.
Leica M lenses have an even shorter register than Minolta MD, and an
adapter is already available to fit them to the Micro Four Thirds mount.
But I doubt there is much demand for a Minolta MD adapter.
The best route might be to have an adapter specially made by SRB-Griturn
of Luton, who specialise in such things. Their prices are surprisingly
reasonable:
http://www.srbfilm.co.uk/