This project took a long time, as I also had to deal with the mirror issues. I believe the rear element of these type lenses need to be in the original spacings to achieve the designed image qualities, which in the case of the FD50L and FD85L, happens to be about 2mm out from the EF adapter toward the sensor. The 5D mirror swings up a little over 1mm from the EF adapter. There is no free ride. The mirror has to be shortened one way or another. I took off about 1.5-2.0mm from the leading edge of the 5D mirror. The edge of the mirror is rough as the silvered glass flecked away. Ugly but done. I put a longer 135mm focal length lens on the 5D and couldn't see the edge of the mirror, so at least I won't be reminded of the mirror grinding everytime I look through the viewfinder.
As I said, the rear element has a set position with respect to the film plane/sensor and I have determined this distance with respect to the distance back from the inside surface of the EOS adapters, I use. I have a jig that positions the rear element. Then, the lens is infinity adjusted, as a normal lens would be.
Most of the time, I convert a lens to EOS with the idea of streamlining the process for the purpose of offering the service. I'm not so sure about this and the FD50L. I actually have a working drawing at a local machinist for a 303 stainless EF flange that screws to the FD lens body with the original lens screws. The problem is the aperture control mechanism. When you pull out the FD mount, you pull out a part that makes the aperture work. That part needs to be re-created.
An even bigger problem is the 5D mirror issue. That is a deal breaker for all but the most extreme alternate lens user. The focusing screen makers cut their screens with a laser. Maybe they can offer cut down 5D mirrors with clean edges that can be installed by the user...
Coming from the crop camera world, I have to say I didn't know what I was missing. The apparent depth of field is much more shallow on a FF body and the bigger viewfinder is so much easier to manually focus. I have the Ee-S screen and a new "universal magnifying eyepiece" (2-13C). The AF-confirm chips I use are programmable for camera AF point, front or back focusing. Between all of the above, I can really get good focus results.
The FD85L has no field curvature that I can tell. I haven't noticed any of the usual aberrations, but I just started using the lens. Wide open flare or fringing is minimal. In the beginning, the 85mm focal length appealed to me more than the 50mm range, and that is still true, today. The camera lens combo is a lot of fun to shoot with and I guess if I had just one fast f/1.2 or f/1.4 lens in the bag, it would have to be an 85mm versus a shorter focal length.
pengland wrote:
Great pic Paul....love it! I had thought you converted the 85mm Aspherical rather than the "L"? Are you using it on a 5D too?
Yes, it is the Grandpa 85 L (as far as I know it is the same optical formula as the FD 85/1.2 L, but it has 9 aperture blades instead of 8) I use it on my 5D and I also plan to use it on the 40D I just bought an hour ago:
Silentlight wrote:
I love to see a shootout of this lens vs. Rokkor vs. C/Y vs. that new Vivitar (which I just returned to Adorama because I didn't like how it handled).
Jim, some day you should try my shaved Ec-C4 screen. Works pretty good. I had difficulty with Ee-S in dim light with slower lenses.
Paul is back? For real?! Excellent
Cheers to you as well. Although, I have mixed feelings about both leaving and returning. Ah, what the hell. Life's too short to worry.
Have you noticed that the price of these is going through the roof these days? KEH wants $800 for them now (and, of course, Kevin wants between $900 and $1400 for the SSC Asphericals, of which he has about 12).
Do you think they realized that people want to buy them to do what we have done?
cogitech wrote:
Have you noticed that the price of these is going through the roof these days? KEH wants $800 for them now (and, of course, Kevin wants between $900 and $1400 for the SSC Asphericals, of which he has about 12).
Do you think they realized that people want to buy them to do what we have done?
Greetings, Paul.
I don't know if things are changing or not, in respect to the FD85L, or the FD50L, or their precursors. We all know how high Kevin is. I'm sure he doesn't sell many in-state with almost 10% LA county tax.
Lens re/sellers know "L" lenses are supposed to be good and may go by eBay asking prices, but do they sell? In my opinion, $450-$550 is a good price for a KEH grade EX+, and I guess I'd pay $600-$700 for a better condition FD85L. It's really all about proper placement of the rear element, a perfect rear element surface, and a cleaning mark free front element. It really is a tough conversion, done the right way. I'm still talking to the machinist about an EF back, but the mirror issues on a 5D are paramount.
A good friend and noted nature photographer sent me a FD55/1.2 aspherical lens for EF conversion. The lens value is from the rarity, optical quality, and excellent condition. But for this situation, the mirror problems were an issue and grinding that mirror to accept the lens was too extreme. I sent the lens back to him. I really wish a viewfinder screen maker would pick up the ball and laser cut 2mm off the leading edge of a 5D mirror.
I don't know if things are changing or not, in respect to the FD85L, or the FD50L, or their precursors. We all know how high Kevin is. I'm sure he doesn't sell many in-state with almost 10% LA county tax.
Lens re/sellers know "L" lenses are supposed to be good and may go by eBay asking prices, but do they sell? In my opinion, $450-$550 is a good price for a KEH grade EX+, and I guess I'd pay $600-$700 for a better condition FD85L. It's really all about proper placement of the rear element, a perfect rear element surface, and a cleaning mark free front element. It really is a tough conversion, done the right way. I'm still talking to the machinist about an EF back, but the mirror issues on a 5D are paramount.
A good friend and noted nature photographer sent me a FD55/1.2 aspherical lens for EF conversion. The lens value is from the rarity, optical quality, and excellent condition. But for this situation, the mirror problems were an issue and grinding that mirror to accept the lens was too extreme. I sent the lens back to him. I really wish a viewfinder screen maker would pick up the ball and laser cut 2mm off the leading edge of a 5D mirror.
Jim,
Congrads - the exercise of endurance has paid off. The weight and smooth focus of the 85's is a feeling to behold.
The FD's are a wonderful optic for the manual focus crowd. Too bad Zeiss can't come out with a ZE or ZF version - and keep a respectable price. Seems like they have the technology. Not an option if you have to re-mortgage the house.
cogitech wrote:
Yes, it is the Grandpa 85 L (as far as I know it is the same optical formula as the FD 85/1.2 L, but it has 9 aperture blades instead of 8) I use it on my 5D and I also plan to use it on the 40D I just bought an hour ago:
Grandpa 85L.....he he...I like that. There seem to be even less of these than the later version. Therefore I think you are a member of another even smaller club as well.
What method did you use to locate and hold the rear element in your conversion? How much do you have shaved from the mirror in your 5D? Any other clearance issues within the mirror box? Is the aperture control as per nFD standard or the older standard?
Do you think a converted FD 55 1.2 would clear the mirror of a 1ds3?
Is your friend selling that converted lens now?
I don't know about the 1ds3, but you could measure it to get an idea. Put a M42-EOS adapter on the camera and measure the clearance to the mirror in lockup position. My 5D gives between 1 and 2 mm. AND, my mirror still hangs occasionally, which leads me to think the mirror returns at different positions.
Point about the 55 aspherical is that the conversion was not done due to the required mirror grind.
