Steve Oakley
July 4th, 2006, 02:00 PM
I've been working on this project since NAB, and finally got a prototype working. This is NOT gaffer tape engineering, but a real mount. The lens will focus to infinity, and the iris works correctly. So first, here are some pics of a mounted Canon 50mm F1.8 FD on the hd100
http://71.98.60.159/50mm/index.html
and a link to some images from the glass on the camera
http://71.98.60.159/50mm/sample_images.html
So the bad news is its not an adaptor you can put onto the lens yourself, then mount to the camera. I actually had to fabricate a 1/3" lens mount, and connect the canon lens to it. The clearances are such between the canon and the JVC that making a reliable & interchangeable adaptor is not likely. The outer part of the back of the canon is almost exactly the same size as the whole in the JVC lens flange. Even in stainless steel, I would not count on a realiable adaptor that would go JVC flange->short tube->canon body mount. Compounding the problem is that the locking lever on the JVC mount is above the locking collar of the body, meaning you would have to also work around that, its that close.
I also had to perform some extensive mods inside the lens in order to remove the click stops, and to make the iris work correctly - as you move the iris ring, the iris moves as expected without the lens being in the "mounted" postion. Normally, a canon lens won't do this without having both the lens mount in the mounted position and one of the rear lever pins pushed over. In attaching the mount, I had to remove both of those levers. So like I said, it required some extensive mods to make work, and this glass will never work on a SLR again although I don't think that is an issue here. This should really be considered a conversion rather than adaptor.
All of that said, the lens works nicely. The common plain 50mm F1.8 will focus to just under 2ft (.66m) continously from infinity. While this isn't a true macro, its close. Note that I can nearly fill about 1/3 the frame with the end of my finger. The lens wide open has a soft, diffused look. this could be do to some shinyness on the adaptor, but once the lens is closed down to f4, its much sharper and the flare seems to be gone. It overall looks nice. At F2.8, there is some flare/diffusion, but sharper than wide open.
Another upside, no breathing. You can rack focus from 2ft to 20ft and nothing moves. This is nice. Chromatic Aberation does exist with this lens, but its a soft pleasing circular pattern that goes evenly around the point rather than the stock lens's up/down pattern.
So I have a 50mm 1.4 that is next to mod. Its an older breech mount, which I think will prove much easier to mod because its not the FD mount with its built in rotation of the mount. I'm also in the look out for a 20mm and 85 1.8 as possible other candidates.
Q1: Will I mod your lens ? at this time no but its certainly a consideration in the future.This will have to wait until I can fabricate a 1/3" mount I am satisfied with, and in small volumes. The next part of this answer will be, can I do it for a price that makes sense, which again depends on fabricating mounts, and the lens in question. Some glass like a 200 2.8, 300 2.8 are prime canidates for modding, and have been for other formats like PL or Arri mount. The price to mod a lens in the $300-$1200 range will look a lot different than the same price to mod a $15 lens. I might consider simply stocking & selling modded 50mm F1.8's too. Many options here. The bottom line for me is that if I get enough interest from people who are really willing to pay for the work, then I can invest in what I need to do this and produce a quality product for a reasonable price.
Q2: Will I sell the 1/3" lens mount by itself ? no. even if I am able to make 1/3" lens mounts I'm happy with, there is still extensive modifications to be made to the lens in order for it to work. This is not a matter of just putting the flange onto the back of the canon and off you go. There are even differences in the canon lens mounts that may require the 1/3 mount to be modified depending on the glass you are mounting to.
Q3: How does the focal length work out ? The focal length of the lens is unchanged. a still lens at 50mm will have the same angle of view that the stock lens has at 50mm. There is no glass added in the mod, nor is this a shoot off a ground glass project like RedRock
Q4: How does the iris work ? the iris functions as expected, it opens and closes as you turn the iris ring without the quirks the FD mount normally has - ie if the lens is unmounted, it moves to midposition and locks there. Mounted it normally sits wide open. The click stop has been removed so that the iris ring turns continuously.
Q5: Is the image flipped or upside down ? No. the image appears normal and correct
So there you have it. It can be done, but not simply. its great to have an option available to mount FD glass, as I've always liked its look.
Steve Oakley
http://www.practicali.com
http://71.98.60.159/50mm/index.html
and a link to some images from the glass on the camera
http://71.98.60.159/50mm/sample_images.html
So the bad news is its not an adaptor you can put onto the lens yourself, then mount to the camera. I actually had to fabricate a 1/3" lens mount, and connect the canon lens to it. The clearances are such between the canon and the JVC that making a reliable & interchangeable adaptor is not likely. The outer part of the back of the canon is almost exactly the same size as the whole in the JVC lens flange. Even in stainless steel, I would not count on a realiable adaptor that would go JVC flange->short tube->canon body mount. Compounding the problem is that the locking lever on the JVC mount is above the locking collar of the body, meaning you would have to also work around that, its that close.
I also had to perform some extensive mods inside the lens in order to remove the click stops, and to make the iris work correctly - as you move the iris ring, the iris moves as expected without the lens being in the "mounted" postion. Normally, a canon lens won't do this without having both the lens mount in the mounted position and one of the rear lever pins pushed over. In attaching the mount, I had to remove both of those levers. So like I said, it required some extensive mods to make work, and this glass will never work on a SLR again although I don't think that is an issue here. This should really be considered a conversion rather than adaptor.
All of that said, the lens works nicely. The common plain 50mm F1.8 will focus to just under 2ft (.66m) continously from infinity. While this isn't a true macro, its close. Note that I can nearly fill about 1/3 the frame with the end of my finger. The lens wide open has a soft, diffused look. this could be do to some shinyness on the adaptor, but once the lens is closed down to f4, its much sharper and the flare seems to be gone. It overall looks nice. At F2.8, there is some flare/diffusion, but sharper than wide open.
Another upside, no breathing. You can rack focus from 2ft to 20ft and nothing moves. This is nice. Chromatic Aberation does exist with this lens, but its a soft pleasing circular pattern that goes evenly around the point rather than the stock lens's up/down pattern.
So I have a 50mm 1.4 that is next to mod. Its an older breech mount, which I think will prove much easier to mod because its not the FD mount with its built in rotation of the mount. I'm also in the look out for a 20mm and 85 1.8 as possible other candidates.
Q1: Will I mod your lens ? at this time no but its certainly a consideration in the future.This will have to wait until I can fabricate a 1/3" mount I am satisfied with, and in small volumes. The next part of this answer will be, can I do it for a price that makes sense, which again depends on fabricating mounts, and the lens in question. Some glass like a 200 2.8, 300 2.8 are prime canidates for modding, and have been for other formats like PL or Arri mount. The price to mod a lens in the $300-$1200 range will look a lot different than the same price to mod a $15 lens. I might consider simply stocking & selling modded 50mm F1.8's too. Many options here. The bottom line for me is that if I get enough interest from people who are really willing to pay for the work, then I can invest in what I need to do this and produce a quality product for a reasonable price.
Q2: Will I sell the 1/3" lens mount by itself ? no. even if I am able to make 1/3" lens mounts I'm happy with, there is still extensive modifications to be made to the lens in order for it to work. This is not a matter of just putting the flange onto the back of the canon and off you go. There are even differences in the canon lens mounts that may require the 1/3 mount to be modified depending on the glass you are mounting to.
Q3: How does the focal length work out ? The focal length of the lens is unchanged. a still lens at 50mm will have the same angle of view that the stock lens has at 50mm. There is no glass added in the mod, nor is this a shoot off a ground glass project like RedRock
Q4: How does the iris work ? the iris functions as expected, it opens and closes as you turn the iris ring without the quirks the FD mount normally has - ie if the lens is unmounted, it moves to midposition and locks there. Mounted it normally sits wide open. The click stop has been removed so that the iris ring turns continuously.
Q5: Is the image flipped or upside down ? No. the image appears normal and correct
So there you have it. It can be done, but not simply. its great to have an option available to mount FD glass, as I've always liked its look.
Steve Oakley
http://www.practicali.com