Convert Canon FD breech mount to FL

[NLsafari]

I have a number of lenses that have the old style Canon FD breech bayonet mount. I love these lenses but what will happen to them if the automatic diaphragm misfunctions on a special lens that is irreplaceable? Since parts for these old lenses are no longer available are they destined for the junk pile or can they be converted to a manual FL style mount? I know that if the camera mirror is locked up the diaphragm becomes manual but you lose functionality. Does anyone know if this conversion is practical?

Raphael

[jim_bielecki1]

The aperture stop-down mechanism is the same on an FD or FL lens.  That big lever at the 6:00 PM position is what stops the lens down (and opens it up).  The lever on the left hand side of an FD lens transmits the aperture to the camera for metering purposes.  I suppose you could take the lens apart and remove the left hand lever, but that's a lot of work for nothing gained.  

FD lenses (breechlock, not FDn) are built like the proverbial brick s***house.  I have no doubt my collection of original FD lenses will long outlive me.

[NLsafari]

Thanks, for explaining how the stop-down mechanism works. I will take a close look at the levers soon as I get aa chance.

Raphael

[gwhitegeog]

I agree with Jim - I don't think overall this is a problem. FD lenses are very strong.

[ben_hutcherson]

Just to be clear, too, FL lenses are still automatic diaphragm lenses, as are R lenses. All of these lenses remain open for composing and focusing until the shutter is activated, at which point the camera both closes the aperture(via the coupling pin/lever) and raises the mirror before opening the shutter(and then lowers the mirror and reopens the aperture after the shutter closes). Non-automatic lenses for SLRs exist, but they're usually seen more on cameras where viewing is not done by the taking lens, such as rangefinders or TLRs. I also have bellows-mount lenses and have adapted enlarger lenses for such uses-these tend to not have automatic diaphragms. The only SLR I personally own/have used without automatic aperture support is my Hasselblad 1000F. Like a lot of non-auto SLR lenses I've used(even in mounts that ordinarily support auto operation) the focal plane Hasselblad lenses have a "preset" ring where you can set the aperture and then a second ring right next to it that lets you quickly and easily close the aperture down to the point set on the pre-set ring. It's not a terrible system-it just takes a few more steps and of course you can really mess things up if you do forget to close the aperture.

It's been a long time since I've played with any of my R mount Canons, but I seem to recall that at least some R mount lenses have a sort of pre-set arrangement available to them even though the Canonflex and the like support automatic apertures with R lenses. I'm fuzzy on details, especially since I've not had that much R stuff(not that there's that much out there even TO have-I think only 3 different cameras models and a handful of lenses) but I also seem to remember that even though the mount itself is compatible, the coupling is different enough that you basically need to use them as pre-set lenses if you want to put one on an FT/Pellix or other FL mount camera.

The FD mount really is the FL mount with a BUNCH of stuff added on-namely a lever that communicates set aperture or allows partial stop-down of the lens if set to minimum aperture-which way it works depends on how the body works(and as a bit of an interesting note, at least to me, Nikon's F mount started using a similar system with the FA when it's set to P or S mode, and the F mount cameras still in production are designed to use this for all modes unless an electronic aperture lens is mounted....). The FD mount also has a lug that mechanically communicates the len's maximum aperture to the camera's meter(fun little side note at least to me on that-Nikon's auto-indexing system as used on most manual focus cameras just relies on the camera knowing how far from maximum aperture the lens is set, something a bit limiting and as designed will only allow for a range of 7.5 stops from max aperture-AI/IA-S/AI-P/AF/AF-D lenses all were made with a lug like the one on FD lenses that can communicate maximum aperture, but there were only 5 bodies that could read/make use of it. The older manual indexing system, or pre-AI in common speak, is capable of knowing exactly what aperture is set on the lens but the camera/meter has to be told or "taught" what the maximum aperture is...Canon's way is much more elegant but required a willingness to ditch legacy compatibility). Finally, the FD mount adds an "Auto" position to the aperture ring, which essentially is just the same as setting the lens to minimum aperture, but locks there automatically and has to be unlocked from it manually, unlike other makes where you just set it to minimum aperture and hope for the best, or maybe have a manually operated lock. FD lenses pop out a small pin in the mount to tell the camera they're set to "Auto", and conversely if you have an FD lens on something like an FTb, it's physically impossible to move the ring into the A position, which isn't supported on that camera. Sorry for the rambling-I just love how well thought out the FD mount was...

In any case, and to bring this around, the most common failure point I seem to see on auto aperture lenses-especially manual focus ones- across most makes is oily blades. I've seen then on FD, FL, and R lenses from Canon as well as plenty of them on Nikon lenses(some Nikons like the 55mm f/2.8 Micro seem especially prone to them, but I feel like I've also seen a fair few on the common as dirt breech lock FD 50mm f/1.8). Camera techs will-rightfully-say this is an improper and probably temporary fix, but if you can get at the blades, lighter fluid and repeat actuation will often get them working. This problem is especially particular to manual focus lenses because it's often the focusing helicoil grease breaking down and migrating. It's a problem that often shows up along side stiff or frozen focus. I have a 55mm Micro sitting on my desk that I actually use occasionally, but I got it nearly free($30 for it attached to an F3 HP that also had issues at a favorite old camera store hang-out) because of a sticky aperture and frozen focus, and I was able to repair it. In any case, I say JUST cleaning the aperture blades is often a temporary fix because the grease will often continue to break down and migrate. The "proper" fix generally is to split the helicoil the clean and regrease it, then clean up all the grease that migrated other places. Splitting the helicoil is fraught with peril unless you really know what you're doing(and please mark it before you split it! I have an AI-S 135mm f/2 in my parts box that may never get back together because I didn't do that...). I mention this being an issue with MF lenses because AF lenses often run either without lubricant or with a dry lubricant, although I have seen it on AF lenses...

[Bettendorf]

1 hour ago, ben_hutcherson said:

Sorry for the rambling-I just love how well thought out the FD mount was...

So do I.   Thanks for all the info.  Keep on rambling !

[gwhitegeog]

Yes, as I said in an earlier post, I always thought that the Canon FD lenses were better designed than their Nikon equivalents though the latter were (arguably) marginally better optically but without doubt better made - they are far less likely at (now) 40 or 50 years of age to fall apart or have mechanical problems. My oldest 'modern' lens is a 1971 Canon FD BL zoom (a 100-200mm zoom!) and a pre-AI Nikkor 135 f2.8 from 1970 (or '69). The former is still going strong with no yellowing in the glass or fungus etc and I don't believe has ever been serviced. The latter had become almost impossibly stiff to focus (but was otherwise perfect) and has just gone for a CLA with my technician in Lisbon. As an aside, the Nikon F3 was always praised to the rafters (yes it did have TTL flash) but I always thought the Canon F1n (launched in 1980 too) was a far better camera, aside from the perennial late 70s problem of very slow flash sync. My F1n I have owned since new (1983) and is still going strong. I have had the speeds, etc checked but it has never needed a service.

 

[ben_hutcherson]

30 minutes ago, gwhitegeog said:

Yes, as I said in an earlier post, I always thought that the Canon FD lenses were better designed than their Nikon equivalents though the latter were (arguably) marginally better optically but without doubt better made - they are far less likely at (now) 40 or 50 years of age to fall apart or have mechanical problems. My oldest 'modern' lens is a 1971 Canon FD BL zoom (a 100-200mm zoom!) and a pre-AI Nikkor 135 f2.8 from 1970 (or '69). The former is still going strong with no yellowing in the glass or fungus etc and I don't believe has ever been serviced. The latter had become almost impossibly stiff to focus (but was otherwise perfect) and has just gone for a CLA with my technician in Lisbon. As an aside, the Nikon F3 was always praised to the rafters (yes it did have TTL flash) but I always thought the Canon F1n (launched in 1980 too) was a far better camera, aside from the perennial late 70s problem of very slow flash sync. My F1n I have owned since new (1983) and is still going strong. I have had the speeds, etc checked but it has never needed a service.

 

Certainly don't mean to reopen a 50+ year debate, especially as now I'm pretty much 99% a Nikon user for 24x36 capture(whether film or digital) but the FD system was my first love and I still enjoy using what I've kept even though I did sell off a lot of my better stuff.

The Nikkor lenses are mechanical works of art with such smooth focusing when everything is right, but I've also noticed that they seem to have more of a tendency to gum up than FL and FD lenses. Aesthetics are subjective, but even back in my Canon days I was always a sucker for stuff like the big fluted focus ring along with the multi-color aperture rings and their corresponding lines. I still use a lot of the chrome nose lenses Nikkors. I actually don't mind using non-AI lenses either, or at least not on an F FTN or F2 with "semi-auto indexing"(no manual setting the max aperture like on the other TTL F finders, and no messing with setting to f/5.6 and lining up the pin like on the Nikkormats). The AI system was always a kludge, IMO, although Nikon did at least make ADR work consistently(Canon tried it on the New F-1 with the AE finder, and even though the numbers were bigger and easier to see, it only worked with the new-style lenses).

I don't think the body debate will ever be solved. I LOVE the F2, although IMO with the chunky metering finders it can get a bit ugly. I much prefer Canon's match needle metering system to Nikon's center the needle, but like the visibility of the 3-light DP3/DP12 finder plus they are much more sensitive. I'm leaving the F out of the conversation, because even though I have a pretty sizeable collection of them(well into the double digits) and they are still tough workhorses, they are a pain to use without a swinging film door and the metered finders get really chunky really fast(the plain prism version is definitely very elegant looking). The F-1/F-1n, to me, feel much more refined, and especially the film advance.

The F3/New F-1 debate I think will last forever. I'm really not a fan of the F3, even though, ironically enough, an F3(non-HP) was my first Nikon camera. The F3 film advance is among the smoothest in existence-it's hard to argue that one. Beyond that, though, my love pretty quickly erodes. I don't like the meter, especially since it's so different from every other Nikon up to then. Canon lets you pick the metering pattern, and most of the time I've used either PC(plain matte partial) or PE(I think that's it? Sometimes I get the screen letters mixed up, especially since E screens are a common choice on Nikons, but I think Canon E screens are split/microprism). I've also always felt that even the bright laser-matte Canon screens had better "pop" than the bright "red dot" Nikon screens.

I really, really hate the squinty little LCD on the F3. It's small, dark, tucked up in the corner of the screen, and honestly doesn't even give you that much information. The New F-1, OTOH, had the best match needle meter ever made as far as I'm concerned. It's big, easy to see, and gives you a ton of information at just a quick glance. If it's dark out, Nikon gives you a tiny little light bulb over the LCD/ADR window that turns on when you press the even tlnier little red button on the front side of the prism with the 3rd hand they expect you to have and hope that it lights things up enough to see while your finger doesn't get in the way of ADR. If it's dark and you need help seeing the New F-1 meter, just turn the knob on the back to "light" and you get nice, non-distrating illumination of the meter when you tap the shutter button and have it stay lit up for several seconds after.

Of course beyond there you can debate the F4 vs. either the T90 or the EOS 1. I've never used an EOS 1, so really have no idea. The F4 is a chunky ugly duckling that can't seem to decide what it wants to be or do, but I love the stupid thing. All the controls are right where I expect them, and nearly every F mount lens Nikon has ever made can function on it in some capacity. The only ones I'd really even leave off the list are the AF-P lenses since there's no way to focus them, but even something like my newest 24-70 f/2.8E is fine on the F4 as long as I'm okay shooting it at f/2.8(and the camera even recognizes that that it's not capable of stopping down the lens) and of course it's a given that VR won't work. Even the new in 2020 120-300mm f/2.8 should work fine on the F4(as in it will autofocus and give correct exposure) as long as you're okay using it wide open. That's something like 60 years worth of lenses that will work on the camera. I have two F4s, including one with the hard to find in the US 4-cell grip. Unfortunately the LCDs in that one are on their last legs, with multiple bleeds and other issues that keep eating further and further into the working area(the LCDs on my other are perfect).

[jim_bielecki1]

5 hours ago, ben_hutcherson said:

It's been a long time since I've played with any of my R mount Canons, but I seem to recall that at least some R mount lenses have a sort of pre-set arrangement available to them even though the Canonflex and the like support automatic apertures with R lenses. I'm fuzzy on details, especially since I've not had that much R stuff(not that there's that much out there even TO have-I think only 3 different cameras models and a handful of lenses) but I also seem to remember that even though the mount itself is compatible, the coupling is different enough that you basically need to use them as pre-set lenses if you want to put one on an FT/Pellix or other FL mount camera.....

This is correct.  Super-Canomatic R lenses are 100% automatic when mounted on a Canonflex camera.  They stop down, then open up to full aperture when you press the shutter button, but the aperture connecting linkage is specific to Canonflex cameras.  You can mount most R-series lenses on a FL or FD bodied Canon, but you'll have to operate the aperture manually.

I often use my 100/2.0 "R" lens on my F-1.  A re-mount of the LTM 100/2.0, it's outstanding, even by today's standards.