Which old Pentax lens mounts can be used on a Canon eos body via an adaptor, KA, m42, or screw mount?

Question

I am looking to buy an old prime Pentax lens for my Rebel t1i because they are cheap (and aparently good quality) and I can use the aperture ring to control aperture during video recording, which is otherwise fully automatic.

Answer 1

i dont think you can put a k mount lens onto an eos mount lens [trust me, ive looked everywhere for documentation, i have a few lenses from my pentax film SLR] i think its because the distance from the pentax lens to the sensor is shorter than what canon's lenses are designed for, so an adaptor would push the lens further away where you need to bring the lens closer to the sensor [you could do some surgery on the lens]



but if you were able to get, or make an adaptor, you'd lose the ability to focus at infinity,



plus it would probably have to be manual focus and aperture,



nikon lenses would work with an adaptor because nikon lenses are are farther from the sensor than canon lenses so with the proper adapter you can use nikon lenses on a canon body, but not the other way around.

Answer 2

To be honest, I think nearlly all the lenses available today from Canon, Nikon and Pentax are much better than the lenses you are trying to use. Pentax cameras probably are the best bet for continuing to use the old M42 universal mount lenses but, I personally think such lenses are far more trouble than they are worth on a modern DSLR body. On the 18-200mm lenses; I think the are a great option when you need to travel light with a DSLR. It's an all in one lens. But part of the reason we use DSLRs is the versatility that comes with not being stuck with an all-in-one lens like a point-n-shoot. Most of the time, I'd rather use my 17-55mm f/2.8 zoom. when I actually need telephoto, I switch to one of my 70-200mm zooms like the EF 70-200mm f/2.8 IS USM. And in low-light, no zoom is able to beat a prime like a 35mm f/1.4 or 50mm f/1.4. That's my experience at least. Beyond all this, there are lots of great cameras on the market today. Pentax is actually among the best but, it's their K20D and K-7 that make it worth owning a Pentax. I'm not sure who at Pentax thought it was a good idea to power their other cameras with AA batteries rather than rechargable Li-ion batteries like nearly everyone else.

Answer 3

Not a bad idea (for video) as I have heard that someone else tried to use their Nikon lens (AI-S) with their 5D Mark II.



Fortunately the new firmware allows total manual control of the camera / lens now. But that isn't your camera, so I digressed a bit.



Found this here http://cameraquest.com/frames/4saleReos.htm

Answer 4

all pentax lenses are pentax K mount, so you would need an adapter from k mount to canon...i don't know if such a thing was ever made...