Canon FD -> EF, what has changed?

kerkko_kehravuo · July 1, 2016

In optical structure, what has changed in Canon lenses when mount went from FDn to EF. For example 14/2,8L, 24/1,4L, 35/2, 50/1,2L, 85/1,2L, 300/4L. Or the others. For shure there are new constructions, I quess that plenty of olds too?

K.

JosvanEekelen · July 1, 2016

Check the cameramuseum.com or online versions of Lensworks. AFAIK the EF 50/1.4 and EF 50/1.8 have similar formulations as their FD counterparts. 85/1.8 is a different lens if I remember correctly. You may assume that there is continuous improvement of lenses, resulting in new lens formulations and/or improvement of details like coatings.

Your question is hard to answer since you will have to look at every lens individually.

kerkko_kehravuo · July 1, 2016

Jos,

Thank you of your reply! I know the question is difficult, that is why I asked it. I thougt that someone had maybe done the rechearch already. Some structures have remaind the same for decades, in Hasselblad line for example 250 mm Sonnar and 38 mm Biogon. And then there are structures that come and go. I guess that most zoom lenses belong to these.

K.

JDMvW · July 1, 2016

The single-focal length ("prime") lenses haven't changed much in basic design, even so far back as the rangefinder lenses, much less FD-mount. But steady improvements, sometimes even without numerical version numbers, have taken place. Some of the major improvements have been upgrades to the focus motors in the lenses, with the ability to manually focus without switching to manual setting. Quieter motors have been introduced with an eye to video use of the lenses. A few new lenses, like the TS-E 17mm lens are new designs with almost unbelievable resolutions of the normal inherent contradictions of lens design.

For all that, some of the classics like the Olympia Sonnar 180mm lens from Zeiss were so good that they reveal the genius of the earlier designers with their slide rules and all. ;) <img src="data:image/jpeg;base64,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" alt="" />

jim_bielecki1 · July 1, 2016

At least regarding prime lenses, almost all EF lenses differ from their FD counterparts. Comparing optical diagrams, the EF 15/2.8, 20/2.8, 24/1.4, 24/2.8, 28/2.8, 35/2.0, 50/1.4, 85/1.2, etc. are all different than the FD equivalents. Which is not surprising. Canon made a big deal, back in 1987, that the much larger diameter of the EF mount would allow them much more freedom to explore different lens designs. Which is exactly what they did when they brought out the EF lens lines.

JDMvW · July 8, 2016

To get a little flavor of the "changes" in Canon primes, here are block diagrams (not to scale) of the Canon 50mm f/1.8 lens from 1952 to 2016

kerkko_kehravuo · July 10, 2016

JDM, thank you! Good view to the subject. Structure is quite far the same. Glass development has made it possible to make the lenses thinner?

K.

JDMvW · July 11, 2016

The main improvements are in focusing mechanism and coatings on the glass, but the zoom lenses have undergone major evolutions.

Of course, some more or less exotic primes (particularly new ones) have been redesigned where Canon engineers felt it was advantageous to do so, but many of the classics have stayed much the same in structure.

flavio_egoavil · July 18, 2016

The answer will be pretty lengthy, but here is a quick comparison of some 1st gen (1987-or so) EF lenses verus their FD counterparts:

50/1.8 -- the EF version has one more group, same number of elements.

24/2.8 -- the FD version has a floating system and is unit focusing, while the EF version has a rear focusing system which (hopefully) also performs close distance compensation. Also, the front element of the EF version is bigger.

85/1.8 -- the EF version is all new, and uses the rear focusing system. The FD version is unit focusing.

28/2.8 -- the FD version had, if i remember correctly, 6 elements and had exxxxcellent performance. The EF version is innovative, it uses an aspheric element to bring down the element count to 5, but I've yet to know about its performance.

50/1.4 -- the FDn version is renowned for sharpness while the EF version does not have the same reputation. So there must be some difference inside, although the diagram is the same.

35/2.0 EF is very different, and way smaller, than the FDn 35/2.0 lens. The EF version seems simplified, however the performance is very good as well.

EF 50/1.2L is totally different to the previous FD 50/1.2L.

flavio_egoavil · July 18, 2016

"JDM, thank you! Good view to the subject. Structure is quite far the same. Glass development has made it possible to make the lenses thinner? K."

I dare to say there were no significant advances in optical glass (as applied to camera lenses) in the last 35 years.

What was different is more application of aspheric lenses -- glass molded, resin molded, hybrid, etc.

I also don't think coatings have improved a dramatic lot compared to 1973 and Pentax's SMC coatings or Fuji EBC coatings. And, on primes with about 5 optical groups or less, even single coating does a good job, so why care about coatings...

What has changed is the state of the art in lens design --- more knowledge leads to better designs. On the other hand those EF lenses need to have quick focusing so the focus helicoid tolerances are looser, the moving mass has to be smaller, and this will impact on the compromises and constraints needed for the lens design.

kerkko_kehravuo · July 19, 2016

Flavio,

Thank you of your good points!

K.

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Canon FD -> EF, what has changed?

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