woodpret wrote:
Hi guys , I'm a newbie here and a real amateur . I have an old Canon EOS 650 and was wondering if the new SLR digitals would accept the lens of this old camera. thanks, Woodpret
Ok I read that as you have EOS lenses with the Eos650 and you want to know if Canon EOS Digital Camera's can use these lenses.
If they are canon lenses they are designed for 35mm film so are big enough to work with all Canon Dslrs. I think that they should work with most if not all Canon Dslr's.
if they are 3rd party lenses then you may run into problems, depending on the lens and the body combination. These will require some researching.
The problem is down to the lens protocol (the language the lens and the body use to talk to each other) When the body and the lens meet they have a conversation during which they talk about things like focal length aperture... Now this protocol has evolved over the years so there is a few variations. Now canon have been pretty good at recognizing their own lenses and have routines built into their firmware to handle older canon eos lenses.
However with third party lenses there is a problem, rather than pay canon for the right to use the EOS protocol they reverse engineered it and got their lenses working with the film bodies. Canon wasn't happy they didn't want 3rd parties eating into their profits by selling competing lenses and there was a court battle which i think canon lost. However they were not forced to keep their protocol the same in later generations of camera bodies and they changed it.
I am kind of lucky that my old 1D mark II is compatible with most of these third party lenses, However more recent bodies are not. So we ended up in a situation where relatively new at the time third party lenses wouldn't work on the newer bodies. I think Sigma reverse engineered the newer protocol and would take in their older lenses and upgrade the firmware on them to make them compatible again but they stopped doing this years ago. unfortunately some lenses never got the upgrade so it's a maybe. I think Tamron had less of a problem.
There is a little more, as well as third party manufacturers hacking the EOS protocol some canon users did as well programing a pic to send the right signals from the third party lens. If you search around online you should find a group that was doing this, they may still be active.
Sigma i think make a usb dock for their current lenses which allows the firmware to be upgraded, and if canon change the protocol again they can update it. Every so often people buy an old EOS third party lens from Ebay and find it doesn't work on their digital body, a clued in Ebay seller will probably warn it is only compatible with film bodies, (and some older EOS D bodies maybe).
So if the lens is canon it will probably work fine with other canon bodies unless it is an EF-S lens these have a squared off rear end and canon full frame bodies have a tapered entrance to the body. so a full frame canon lens will fit a crop frame body. But an EF-S lens will not physically fit a full frame body which is good really since the image circle of a crop sensor lens will not cover the whole of the full frame sensor causing dark corners.
Nikon has a dx mode which crops out the pixels from the edges of the sensor as does Pentax so you can use a crop sensor lens on those full frame bodies.
As for modern canon lenses on a film EOS body the EF-S lenses do not physically fit and I haven't a clue if any of the EF lenses will work or not.