FD to EF-S Adapter -- Possible?

[ian_hobday]

As everyone knows, FD glass can not (easily) be adapted to the EOS/EF

mount. It can only be adapted with either a loss of infinity focus, or

by using the extremely rare and expensive Canon adapter which contains

a glass element.<br>

<br>

The reason for this is that the rear element of FD glass needs to be

42mm from the film/sensor surface. The EOS/EF mount places the rear

element 44mm from the film/sensor surface.<br>

<br>

This leads us to EF-S. EF-S lenses also place the rear element of the

lens closer to the sensor than the EF mount does. Although I have

googled this, I can not find the exact distance. However, from the

look of EF-S lenses, I'd say it is slightly more than 2mm closer.<br>

<br>

So.... Is there any reason that an FD to EF-S adapter couldn't be

made? There is a *lot* of very cheap and very high quality FD glass

around, especially here in Japan. I'd love to be able to buy some of

this glass!<br>

<br>

Anyone have thoughts or ideas?<br>

<br>

Thanks in advance,<br>

<br>

Ian<br>

--<br>

Ian Hobday<br>

Osaka, Japan<br>

<a href="http://hobday.net/photos"

target="_blank">http://hobday.net/photos</a> (Opens in a new window.)

[bobatkins]

In what way would it differ from an FD to EF adapter?

<p>

If you can adapt FD lenses to a regular EOS mount isn't that what you want? Regular EOS EF series lenses fit all EOS bodies, including of course those that can also take EF-S lenses.

<p>

See this article on about <a href="http://www.bobatkins.com/photography/eosfaq/manual_focus_EOS.html">Manual focus lenses on a Canon EOS body</a>

<p>

The question of whether you could fit an EF-S lens on an EF only body however is valid. Yes, you could make such an adapter - however it would totally defeat the whole purpose of the EF-S lens since the adapter would have to be a low power multiplier which would increase the focal length and move the lens further away from the sensor!

[damian_tinsley]

Bob,

 

I think the point was that if you could put an FD lens on a DSLR APS-C sized sensor WITHOUT spending a lot and also keeping infinity focus because the back end of the lens is able to be physically closer to the sensor than it can be in a full frame DSLR, then Ian could buy a shedload of fast, long L series FD telephotos for a song and be laughing all the way to the optician to make sure his eyes were up to the job of focussing the things :)

 

Don't think this was anything to do with fitting EF-S lens to full frame as it would (presumably) vignette like mad and be essentially unusable even if it did fit.

[User_1172872]

"In what way would it differ from an FD to EF adapter?" I think Ian wants an FD to EOS adapter that would retain infinity focus for FD lenses on cameras with an EF-S lensmount, but without any glass in the adapter. If I understand his idea correctly, since the cameras with EF-S lensmounts have shorter mirrors, the adpater could move the FD lens further back into the camera. Seems to the first issue is whether the EF lensmount is wide enough to allow this.

[kin_lau]

Okay... I'll bite. I've got the EF-S 18-55 & DReb in front of me, an FD 28mm & 55mm, and the size of the breech lock would cause problems. Then there's the problem of those metering prongs that stick out the back.

 

So the answer is _still_ no.

 

Get a M42 to EOS adapter, and look for SMC Super Takumar's, or Fujinon's and many others. They're probably even cheaper. Didn't CV just put out a new "Topcon" 58mm f1.4 m42 lense?

[eugenijus_kostrubinas]

FD to EF is enough in any case: http://osnews.pricegrabber.com/search_getprod.php/masterid=745669/ut=d5a465dfb7651ea3

 

And it is nor rare, you see :)

[steve_dunn2]

<p>Eugenijus, do you actually have this adapter? Due to the different registration distances for EF and FD lenses which Ian mentioned, I very strongly suspect that this adapter loses infinity focus (in order not to, it would either have to have optics in it, like one of Canon's adapters did, or it would have to perform a magic trick by mounting the lens partway inside the body), and therefore doesn't solve Ian's problem.</p>

 

<p>As for the FD lenses ... Kin, if you didn't care about whether or not they could ever be used again on an FD body, could some surgery take care of those issues? I don't use FD equipment so I'm just throwing an idea against the wall to see if it might stick ...</p>

 

<p>If you don't already have a stock of FD lenses you'd like to use on an EF-S body, the suggestion about using adapters for non-Canon lenses probably makes more sense. See also <a href="http://photonotes.org/articles/eos-manual-lenses/" target="_blank">the photonotes.org article on using manual-focus lenses on EOS bodies</a> - if you're not already familiar with some of the issues involved, it might be worth reading before you go down this road.</p>

[bobatkins]

FD to EOS is a common adapter. There are two versions, one that loses infinity focus but has no optics, one that keeps infinity focus but has optics which act as a low power multiplier.

 

It would work just fine with any EF-S compatible body.

 

Could you mount an FD lens INSIDE the lens mount of an EOS body is the question. On an EF-S compatible body you do have a little more mirror clearance. However there isn't room to get an FD lens mount INSIDE the EF flange. You'd have to strip the mount off the FD lens. You can do this, I've heard of people doing it. In fact you can do it on some FD lenses and mount them on full frame EOS bodies, because there are many FD lenses that don't have any optics right at the back of the lens. Any telephoto for example.

 

Could you make a simple adapter? No. It's not mechanically possible without modifying the FD lens.

 

If you want to put non-EOS, non-EF glass on an EOS body, look for Pentax screw mount or even old Nikon lenses. They can be fairly easily adapted.

[andrew robertson]

To add to what Bob already said, there are actually two kinds of FD - EOS adapters that

allow infinity focus. One is made by Canon, and was never sold in stores. The only way to

acquire it was to be a member of CPS (Canon Professional Services) and have a big

investment in long lenses. It's a very high quality 1.2x teleconverter, and will only take

certain of Canon's longer FD lenses. Consequently, it's quite rare and expensive on the

used market.

 

The other kind of FD-EOS adapter is the non-Canon kind. They're cheap and commonly

available, but almost universally regarded as being quite crappy. I'm not sure why one

would go to the trouble of buying one of these.

[ron c sunshine coast,qld,a]

"Could you mount an FD lens INSIDE the lens mount of an EOS body is the question. On an EF-S compatible body you do have a little more mirror clearance. However there isn't room to get an FD lens mount INSIDE the EF flange. You'd have to strip the mount off the FD lens. You can do this, I've heard of people doing it. In fact you can do it on some FD lenses and mount them on full frame EOS bodies, because there are many FD lenses that don't have any optics right at the back of the lens. Any telephoto for example"

 

<P>Bob has hit the nail on the head-this is the issue you have to deal with.

<BR>I know *most* FD lenses wouldn't fit inside the EOS mount...and i'm guessing none would.

<P>I'm one of those rare (lunatics? :) ) that have removed the mount from FD lenses and attached an EOS mount.It's not alltogether mind numbingly difficult,just fiddly.<P>One thing that *is* impossible is converting most wide angle lenses.The optics would simply jam the mirror on a normal EOS camera

<P>.....but -and this get's to the heart of your orriginal question- the digital bodies would indeed have more leeway for doing these type of conversions with the wider angle FD lenses.

<BR>With EOS film bodies the lower focal length limit was about 135mm,some shorter models may have been possible but i've forgotten which ones .<BR>With digital i've easily used an FD 85/1.8 and i'm guessing much shorter focal lengths could be used.

<P>There is even the distinct possibility that ALL FD lenses may be convertable to the 1.6 crop canon DSLR's

[User_1172872]

" I'm one of those rare (lunatics? :) ) that have removed the mount from FD lenses and attached an EOS mount.It's not alltogether mind numbingly difficult,just fiddly."

Do the screw holes simply line up? How much machining is involved?