Yes, I am going to try to convert a FD lens to EOS mount. I've seen many different conversions here with great results. I have also seen the resell price of the lenses go sky high. The $1300 kevincamera is asking for a Oly 18/3.5 is crazy.
The gap I'm trying to fill is the 17-18mm on 1.6 crop Canon. This would give me a 27-30mm equivalent on FF. I think I can make a 27mm equivalent focal length work for my widest lens. The other alternative is a 5D or 5DII, to give my Leica 28mm, a true 28mm, but at the expense of size and weight.
My choosen victim is the Canon FD 17mm f/4 lens that is on its way to me. Its not an L lens, but it has floating element groups, and is the right focal length, at the right price. The only reports of its performance on the internet are positive, but that maybe due to the lack of an EF equivalent lens. I also have ordered a Sigma lens EOS flange replacement part for this job.
I considered the 17mm Minolta lens as a candidate, because of the ease of conversion of the 58mm f/1.2 I've seen here, but availability is rare.
So, I've seen the website of the FD to EOS conversion, the guy from Rochester Institute of Technology using electricians tape in his conversion...
Anyone else know of a website that could help me in this matter?
JimBuchanan wrote:
I have also seen the resell price of the lenses go sky high. The $1300 kevincamera is asking for a Oly 18/3.5 is crazy.
kevincamera seems to be living in a dream world with the pricing for most of the items. Of course, if you really *need* a lens, then you know where to go because no one else is willing to pay those prices.
Here's a link to an FD 55/1.2 conversion. Looks a bit much to bother with, but a fun experiment none the less.
There are shops in Korea that will do the conversion for $100, or so I've heard. I'm going to have an FD fast 50mm lens converted once I can find the shops that do a good job.
StevenPA wrote:
There are shops in Korea that will do the conversion for $100, or so I've heard. I'm going to have an FD fast 50mm lens converted once I can find the shops that do a good job.
Really? Maybe I'll have to ask around this weekend. I'll let you know if I find anything
The Sigma EOS flanges came yesterday and are chromed brass, flange is 1.9mm thick and precisely machined. I've heard the opinion a brass M42-EOS adapter is a good flange to use, however the aluminum M42-EOS adapter I have is only a bit over 1mm thick, if that's important.
I received the Canon FD 17mm lens, today and didn't waste time taking it apart. I got the aperture ring working, but need to make a spacer for between the lens body and new Sigma EOS flange. There are 2 reasons for this. To add the appropriate optical path and to provide the stock for 2 different diameter "lug patterns".
Sorry for the lack of photos here, as I haven't joined image upload. I spent all my money on the user FD 17mm lens.
I do however have a Flickr photo series available at:
hmmm? Well, then, here are the descriptive captions:
1. Starting with my working drawing in the bottom left-hand corner and going clockwise: original retainer part, new Sigma EOS flange, FD lens taken down to aperture control level, and old and useless original parts in upper right-hand corner.
2. Lens needing about 6mm more optical path at new EOS flange surface. Although, the rear element appears to protrude quite a bit, with the needed spacer in between the lens and EOS flange, the element will be flush or inside the flange throat.
It has become evident why the FD lens is so hard to convert to EOS, besides the need to shorten the optical path by 2mm. In the top view, the "lug pattern" is shown. There are 3 points where the lens flange can be screwed into the body of the lens. The radius of this circle is smaller than the typical EF lens and in fact is very close to the radius of the EF flange that inserts into the EOS body. Therefore, a spacer disk needs to be made to use these existing 3 holes in the lens body and a second threaded set for the new EOS flange to be screwed to.
3. Looking down into the lens, the aperture control mechanism is shown. Most of the guts of this has been removed, as there is no auto diaphram capability using an EOS camera. About 5 o'clock is the hand made aperture "finger" that links the aperture ring with the actual aperture blade control. This worked out very well.
I've been looking at 8mm circular fish options and came across this. Jim, I thought you and Paul might get a kick out of this. Not an FD or a Rokkor, but check out the date.
The most difficult part I guess for the other lenses other
than my FD 55/1.2 S.S.C is re-installing aperture linkage.
My conversion had bad moment to re-install aperture linkage,
though FD 17/4 looks much worse than my FD 55/1.2.
My first attempt resulted to over-inf, but I used the center
bottom part in Paul's first photo to make it nearsightedness
first, then slim/file down that part to achieve infinity properly.
It is still slightly nearsighted, but leave it till I get 5D back
from the repair shop.
JimBuchanan wrote:
hmmm? Well, then, here are the descriptive captions:
1. Starting with my working drawing in the bottom left-hand corner and going clockwise: original retainer part, new Sigma EOS flange, FD lens taken down to aperture control level, and old and useless original parts in upper right-hand corner.
2. Lens needing about 6mm more optical path at new EOS flange surface. Although, the rear element appears to protrude quite a bit, with the needed spacer in between the lens and EOS flange, the element will be flush or inside the flange throat.
It has become evident why the FD lens is so hard to convert to EOS, besides the need to shorten the optical path by 2mm. In the top view, the "lug pattern" is shown. There are 3 points where the lens flange can be screwed into the body of the lens. The radius of this circle is smaller than the typical EF lens and in fact is very close to the radius of the EF flange that inserts into the EOS body. Therefore, a spacer disk needs to be made to use these existing 3 holes in the lens body and a second threaded set for the new EOS flange to be screwed to.
3. Looking down into the lens, the aperture control mechanism is shown. Most of the guts of this has been removed, as there is no auto diaphram capability using an EOS camera. About 5 o'clock is the hand made aperture "finger" that links the aperture ring with the actual aperture blade control. This worked out very well.
No problem. All I did was browse to the full sized images on your flickr page, right-click and "copy image location", then paste urls directly into my post here at FM. No fancy code or anything is necessary. This is how many of us post images here even though they are hosted elsewhere. It uses none of FM's bandwidth, of course, and it is simple to do.
The most difficult part I guess for the other lenses other
than my FD 55/1.2 S.S.C is re-installing aperture linkage.
My conversion had bad moment to re-install aperture linkage,
though FD 17/4 looks much worse than my FD 55/1.2.
My first attempt resulted to over-inf, but I used the center
bottom part in Paul's first photo to make it nearsightedness
first, then slim/file down that part to achieve infinity properly.
It is still slightly nearsighted, but leave it till I get 5D back
from the repair shop.
Terrific news, KOJI!
Looks good. Can't wait to hear how the lens performs and any other details and photos you might be willing to provide would be much appreciated, of course.
mcbroomf wrote:
I've been looking at 8mm circular fish options and came across this. Jim, I thought you and Paul might get a kick out of this. Not an FD or a Rokkor, but check out the date.
I did not document the process of FD->EF conversion, so
not much I can show except the above photo of my HP.
Tough some examples I took today are here (in the last row)> http://www.pbase.com/kkawakami/fd_55mm_f12_ssc
I may organize how I did it retrospectively.
UPDATE: I added a couple of photos in the above.
My conclusion: It is rather surprisingly easy to do for FD 55/1.2 S.S.C.
except re-installing aperture linkage.
I have managed to fashion a 2 part EOS adapter to the FD 17mm lens. The photo shows an old well mangled M42-EOS aluminum adapter that I tried to adapt to the FD lens. The FD lens has a 3 bolt pattern on the body, that the mount screws to. The "new" EOS flange needs about 3mm more optical path back from these 3 mount points. The problem with the M42-EOS adapter is the bolt pattern is right on top of the flange fingers as shown in the photo, not to mention the 1.5mm thinness that a screw head needs to clear. http://farm4.static.flickr.com/3007/2619385150_4cd7c25229.jpg
My solution is to use a custom ring that has a male M42x1 thread on it (shown in photo) that basically makes the FD lens into an M42 lens. This ring is screwed to the FD body with the original screws. Then, a conventional M42-EOS adapter can be used to mount the lens. I am currently waited on delivery of a bronze M42-EOS adapter, so I can drill the 3 holes in the custom ring for focus mark on the lens to point straight up 12:00. http://farm4.static.flickr.com/3186/2618561979_bee69440d2.jpg
If all FD lenses use the same radius for the mount points, then this custom ring with M42 male threads could be used for a variety of FD lenses. Although, I have a more than adequate Summicron-R 50mm, I would like to compare it with a Canon FD 50L f/1.2, for example, with the floating elements. (Canon EF 50L has just one lens group assembly)
As for this 17mm, I am prepared to realize that it may not be that great a performer. I see chromic abberations in the field even stopped down, but I want to wait for the final verdict after I have the register correct on a properly installed mount.
One thing I've learned is the exactness that a floating element lens requires for good image quality at infinity. This explains the problems of the likes of C/Y 21mm Distagon, with infinity on a thinner adapter.
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