FD lenses on Digital EOS; do you really need a 1.26x converter

Discussion in 'Canon EOS' started by jim_fix, Jan 8, 2007.

  1. I'm well aware that FD lenses can be used on EOS bodies with an image correcting
    lens adaptor. From what I've read this is effectively a tele-converter to
    correct for the different mount lengths in FD vs. EF.

    Since the low end DSLR bodies have a 1.6x crop, is it really necessary to us the
    standard FD to eos adaptor, or would a simple mount converter (like an eos to
    Nikon adaptor) with no optics work?

    This would effectively be the same as a macro extension tube of a few mm.

    Would this lose infinity focus?
  2. Yes, it loses infinity focus.
    Great if you have use for an all-manual close-up/macro lens.
    The 1.26x is just there because that's what you get when you correct the infinity point; digital crop factor is totally irrelevant.
    Bob Atkins has a great writeup on this on his site.
  3. Yup, makes no difference. Without the optics in the converter you can't get infinity focus on either full frame or APS-C format cameras


    As long as you only want to do macro work, you can do without the optics.
  4. Ok, next question, how much do you lose from the focal range? How close to infinity do you get?
  5. It depends on the focal length of the lens. I believe that the good macro adapter adds 12mm. This means that a 24mm lens will only focus to 1:2 at infinity. A 50mm lens will only focus to about 1:4 at infinity. A 100mm lens will be roughly 1:8, which I believe is about the equivalent of the minimum focusing distance on a typical 50mm lens.

    Recently, one of the moderators of the FD yahoo group had a friend install and EOS mount on an FD 1.4x teleconvertor. This retains infinity focus, but is a much less expensive option. Like the 1.26, though, it will only work with a handful of longer lenses.
  6. I met a man a few months back who used a FD 500 f/4.5 L on his 20D with just a mount adapter (without optics). He said it worked fine for all his needs. He said he could still focus to infinity because that lens had some scope to focus past infinity normally.

    A question to Bob Atkins: does this sound plausible? Alternatively, if the maximum focus distance is something like 200m, would the lack of infinity focus not matter because many people would be unlikely to shoot more distant subjects except for landscape purposes, in which case the lens would be stopped well down for extra depth of field?
  7. Fair call. Apart from say a mountain, I can't see using a 500mm for landscapes as very common. Isn't that why wide angle is so popular?

    That was a very useful answer BTW, as I'm interested in FD lenses mainly for telephoto uses.
  8. At least in the FD range, most of the L telephotos do have some slop in the infinity focus. This is because the fluorite elements used in all but a couple of the L telephotos can expand as they heat up, thus changing the optical formula slightly. Incidentally, the orignal reason for painting the lenses white was to minimize expansion of the fluorite element in the hot sun.

    With a long lens like a 500, it sounds entirely plausible that an extra 12mm of extension wouldn't have that much of an effect.
  9. It's not just fluorite; everything expands in the sun. The "white" barrel started with fluorite lenses, as fluorite is supposedly more easily damaged than standard optical glasses; it's since become a marketing thing as well.
    I've owned seven EF lenses over the years, none of which include fluorite elements (and two of them are "white"). I just tested the four I currently own, and all four can be focused at least slightly past the infinity mark, with two of them going significantly past it, one moderately past, and one barely past. I believe the three I no longer own also could be focused past infinity.
  10. I had a Canon FD 400mm f2.8 L and the Canon 1.26x FD-EOS adapter, and I also had the cheap adapter that is now widely available. I used them on a Canon EOS Elan IIe with Kodachrome 25, Ektar 25 and Velvia 50 and I also used them on a Canon 10D.

    Of course for approximately $1000 USD the Canon 1.26x works incredibly well with almost no loss of quality, even better than a Canon 1.4x regular converter.

    The cheap converter with the glass in it to achieve infinity focus was essentially garbage, making the L glass provide images that looked like they came out of a disposable. The only lens I really had any luck with was the 80-200/4 L but at f8 to f16 only!

    I tried removing the glass from the cheap converter but the 80-200/4 L would only focus to about 15 feet, and the 400/2.8 L would only focus to about 40 feet. I never encountered this focusing past infinity thing on the 400. So 40 feet might be good for some birds or your neighbours but since I wanted to use it for sports at 70 to 250 feet it was useless to me.

    I sold everything FD and invested in, just as affordable, manual focus Nikon glass. Now I use Nikon's 14/2.8, 28/2, 50/1.4, 200/2 and 400/2.8 on my Canon EF bodies with cheap mechanical adapters. You can do the same with Contax/Zeiss and Leica R glass as well as others. Good luck.
  11. How close you get to infinity depends on the focal length of the lens. The longer the focal length the closer you'll get to infinity.

    I can believe that a 500/4.5 is OK. I'm not saying it is, just that it's not impossible since it's a long focal length lens and it can "focus past infinity" anyway.

    Without optics you have a short extension tube, and the effect of an extension tube on focus depends on the focal length of the lens. If it's 10mm of extension and you have a 50mm lens, the farthest focus distance would be around 0.3m (1ft) With a 200mm lens it would be around 4.2m (14ft). With a 500mm lens it would be around 25m with the lens focused exactly at infinity.

    Note 10mm of extension is just a guess. I don't know how thick the FD->EOS adapters are.
  12. Bob,
    The good Canon macro adapter is 10mm thick. When you add in the additional 2mm of difference(FD is 42mm, EOS is 44mm), it acts like a 12mm extension tube.

    I'm not sure what you end up with if you punch the glass out of one of the cheap adapters.
  13. I have found the cheap adapter ok for closeups with optics removed, fits on FD auto bellows as the cable release can be used to close down aperture, leaving focus easier wide open. the 50mm seems to focus at about 10in with FD EOS adapter no optic,. couple of pix I put on portfolio showing with and without optics shows some deterieration.

    I tried an old 500mm lens FD mount + a FD 2x macro TC (kenko) adapter with optic, + 20d, boat over 1/2 mile out ==1600mm+ at f11, never bothered since. this is full frame just resized.
  14. Hi, I have read somewhere that some older manual tele lenses could be adjusted furthe past infinity, didn`t the lenses go past inf to accomodate infra red film. I`m wondering how far you`d have to go to make up the difference?
  15. If your lens extends to focus, you'd have to retract it an extra half inch past nominal infinity to make up for a 12mm extension. That's a lot. Both my FD teles (200/2.8 and 400/4.5) are IF, so it's a bit different. If I get ambitious I'll dig them out and see how they do with my de-opticated Adorama adapter.
  16. Instead of removing the glass from a cheap FD to EOS converter, why not just unscrew the flanges from the converter and mount them together, without the tube. Or use the mounts from a pair of extension tubes, or from a faulty FD-mount camera and a faulty EOS lens. Then the converter may build perhaps 4 or 5 mm, corresponding to a 6 or 7 mm extension. Still a lot for a normal lens, but maybe enough to get focus close enough to infinity on a long telephoto.
  17. Using a 5D II with the 1.4X-A on a Canon 500mm f4.5 L (700mm) and a cheap no-glass adapter focus was possible to 55 yards, which covers much of whatever might be
    a subject for this lens. For shorter or longer telephotos a simple ratio should be close enough.
  18. I have a couple of old Canon FD lenses that I’ve wanted to use with my EOS 40D and 5D Mark III. I have seen FD to EF lens conversion kits – not lens adapters – that actually let you change your FD lens mount to the EF lens mount without additional optics. The process is also reversible. That said, I never worked up enough nerve to try a conversion kit but may be getting bolder now that I am technically older than dirt. The conversion claims full infinity focus and lens function.

    I have no feedback whatsoever on these kits and their quality or longevity.

    One source for these kits is FD to EF Conversions.

    There are also several videos on Youtube showing the lens conversion process. YouTube

    Has anyone had experience with an FD to EF lens conversion kit? I there anyone out there that can help motivate me to convert a couple of lenses?
  19. This thread is from 13 years ago. Not sure any of the participants are still around.
  20. Well this is a blast from the past. All those lenses that I mentioned above in 2007 are gone, one just recently. The Canon FD 800mm f5.6 L with a superthin no glass cheap adapter will focus to about 400 feet, which has served me well for two years now. Back in 2006, I sold my 1.26x for $1200, and I just replaced it with one for $225! Could not resist getting if for the FD 800. Also picked up the Kenko 2x FD-EOS that someone mentioned above for $30, and have not tested it a lot yet, but seems perfectly acceptable.

    Ed Mika, just google his name, has been making mount converters for many years now, but has had to shut down production now and then. He has not made any more in about a year now. I have given up on the idea of building an FD arsenal again because his mount conversions are no longer available, at least for now. They are about $75 each.

    I completely lucked out last week when I found someone local selling an edmika converted Canon FD 55mm f1.2 SSC Aspherical and snapped it up. That was the one FD lens that I really wanted for my 5DSR. The mount is solid and mounts/dismounts beautifully, even more solidly than EF lenses!

    Ed Mika now recommends Simmod for mount conversions, but they are 2 to 3 times the cost, and I am not familiar with how they make theirs. It says they do ALL FD lenses, but I am not too sure about that. It took Ed Mika several years to develop mounts to allow infinity focus and minimize mirror contact to rear of lens. My 55 Aspherical does not hit the mirror until it is set to infinity, at which point I have to use Liveview to lift the mirror out of the way before I turn it to infinity.

    I can highly recommend the edmika kits and any lens that has already been converted. Sadly I did missed a FD 35 TS with edmika, and I just missed the kit alone for the 35 TS on the auction site.

    Good luck!

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