cmuseum

I had asked for the lens model because with some lenses the aperture lever can be locked. The FD 50mm 1:1.4 SSC being one of them. But I realized that this cannot be causing the issue. I can think of three potential issues: Lens not set to auto mode (green "A" or circle) but small aperture. (Kind of unlikely when you say you have tried different lenses.) AE switch bad. The viewfinder should always show the "M" symbol in this case. Operating the AE switch a few times can help. The AE switch is the pin located at the 8 o'clock position of the mount (camera side, viewed from the front). AE unit bad. This unit controls the aperture signal lever (the one moving vertically at the right hand side of the mirror box when viewed from the front). You can try to test the AE unit's function like this: Cock camera, set to Av mode and f1.0, press and keep pressed AE switch pin, apply gentle force directed towards the camera bottom to the aperture signal lever and release the camera. The lever should only move a tiny bit if at all. If it moves all the way down then the AE unit does not work properly.

What lens model do you use, e.g. "FD 50mm 1:1.8"?

I have no experience with that but sturdiness would also be my concern. I would maybe consider reinforcing the fork part at the cost of it going less easy into the film spool. It may also turn out difficult making the rather fine thread at the top of the shaft. My personal preference would be machining it. Large scale model builders may have experience making parts of this size. Unfortunately it's not as simple as with many other cameras. The click-stop spring will lock the shaft when pushing it down and the left top cover will have to be taken off in order to release it. Remove the pin face screw sitting under the rewind crank. (Hold the shaft, don't hold the rewind knob!) When taking off the rewind knob be careful not to loose the small spring, pin and washer underneath it. Remove the flash socket. It screws out. Best is to use a 10mm flexi-clamp type wrench. Remove the front cover (four screws). Remove the left top cover (two screws). Push the rewind knob release button while pulling the cover. Looking from the rear of the camera, carefully bend down the right-hand side capacitor at the bottom of the PCB a bit. With some sharp-ended tool reach into the camera from behind (between PCB and capacitor) and push the click-stop spring (located at the right-hand side of the shaft holder) towards the viewfinder. This will release the shaft.

Getting one machined or 3D-printed.

Focus position does not really matter. But setting it to infinity moves everything closer to the back and that may make installing the mount assembly a tad easier.

I don't have that exact type of lens at hand currently. But from my general experience with breech lock lenses my procedure would be like this: Remove the silver stopper and unscrew the breech lock ring from the mount assembly. Set aperture ring to "A" (or the green circle, resp). Lock the aperture control lever. Reinstall the mount assembly. Move the aperture signal lever while positioning it so that it matches the claw in the lens. Insert the three screws but don't fully tighten them yet. Unlock the aperture control lever and check proper function of the aperture levers and ring. If anything is wrong remove the mount assembly and try again. Insert the silver stopper in the slot at about the same position as the black stopper. You should be able to tell the correct orientation by matching the holes with the breech lock ring. (I think in your first picture it has the wrong orientation, but I am not entirely sure about this). Screw on the breech lock ring. Turn it all the way to the end of the thread, then turn it back until the holes match the holes of the silver stopper. Insert the stopper screws. This may be tricky. I always use a longer screw of the same size for "catching" and holding the stopper. If you don't have one a magnet may come in handy. If you cannot get the screws in remember the stopper position, disassemble again and start over with the stopper already installed. Tighten all screws. Don't loose the EE pin (3 o'clock position in second picture)!

With both, the "old" F-1 and New F-1 the rewind shaft and the fork are one piece. I don't think the fork can be replaced separately New F-1 shown on the left, "old" F-1 on the right. Looking at both shafts (New F-1 top, "old" F-1 bottom) I doubt that the shaft from the ebay offering is from an F-1 at all. The seller is known to be one to be avoided.

I am afraid the part pictured won't fit your camera. The New F-1 rewind shaft has the grooves at positions different from the "old" F-1 shaft. The "old" F-1 rewind shaft fork has a larger diameter than the New F-1 so it would likely not retract fully.

The spring-loaded pressure plate on the inside of the back door will press the film against the rails and keep it flat.

Unscrew the retaining ring around the release button using a piece of leather of rubber (e.g. bike tyre hose). If it is too tight try using a pliers with flat jaws or a "flexi clamp" type of wrench. Pull the pin that sits underneath the button. When turning the camera on with the button and the pin removed, does the meter still come on? If not, check if the pin is bent and may jam. If it still does come on I would further disassemble the camera to get access to the actual switch.

Unfortunately you will have to find out by try and error.

Quick note to future readers who may find this discussion before disassembling their lens: The lens does not have to be taken apart that far for cleaning the diaphragm. See the very end of my post. I assume you have version II of the lens. You can tell apart version I from II by the green mark on the aperture ring: Version I has a green ring, Version II has a green "A". Version I also is larger and heavier than Version II. See the picture below, Version I shown on the left, Version II on the right. In order to reassemble the lens your goal is matching three parts in two ways. The three parts are the rear lens barrel (still attached to the camera, picture 5), the double helicoid ring (picture 3 and 4) and the inner lens barrel (picture 1 and 2). The inner lens barrel has to have proper orientation to the lens mount so that the levers protruding from its rear match their counterparts. At the same time the inner lens barrel has to have the right distance from the lens mount flange so that infinity focus can be obtained. I suggest removing the lens mount for reassembly as this will make things a lot easier: Remove the lens from the camera, move the aperture lever to the manual lock position, unlock the breech lock ring, remove three screws visible through the recesses of the breech lock ring, take off the lens mount. Caution: Two spring-loaded steel balls and the EE pin sit under the mount and are lost very easily. You will now have to assemble the three parts in a way that gives you the configuration shown in the two pictures below. The left edge of the recess in the double helicoid ring has to match the yellow index. The inner lens barrel has to have proper orientation to the lens mount. The distance from the inner lens barrel to the double helicoid ring (first picture) is 6.2 mm. The distance from the double helicoid ring to the rear lens barrel (second picture) is 4.7 mm. Pictures and measurements are from a lens with a serial number only 15,000 units away from your lens. You would usually make notes of the configuration during disassembly. It does not have to be this exact setting. Any setting within the focusing range would be fine as long as you remember the parts' positions and take measurements. And you would count turns from this setting until the parts separate. I haven't disassembled the lens as far as you did and hence cannot give you exact guidance on the next steps. It may take you a lot of try and error until you hit the target configuration. From general experience with other lenses I would start with screwing the double helicoid ring into the rear lens barrel a turn or two. Then screw the inner lens barrel in until its slots match the guides of the rear lens barrel. Then futher screw in the double helicoid ring while holding the inner barrel static until the guides slide into the slots. Now check if you can hit the target configuration. No? Try again but alter one of these parameters: Starting position of double helicoid ring, number of turns for the double helicoid ring, starting position of the inner lens barrel, number of turns for inner lens barrel. The threads usually are multi-start type and that's why starting position matters. Next restore the lens mount, seat the front lens assembly into the inner lens barrel and restore the focusing ring. Check if infinity focus can be obtained. The shop would use a calibration device called a "collimator" for doing that. As it's very unlikely you have one available, use some sufficiently far target (moon in a clear night would be perfect) and a viewfinder magnifier. If infinity focus is just a little bit off, reposition the focusing ring (you would usually mark its exact position during disassembly). If it is far off you haven't hit the target configuration (or my measurements do not match your lens). After completing reassembly, let us know how USD 100 now sound to you ;) (Consider the shop may not even have a copy of that lens to take measurements from...) As mentioned at the very beginning the lens does not have to be disassembled so far for cleaning the diaphragm. My procedure would be: Remove name ring, remove front ring, remove focusing ring (mark its position), remove front lens assembly. Remove lens mount, detach spring from diaphragm lever from the rear. From the front, remove three screws and take out diaphragm base, aperture leaves and diaphragm rotor. Clean and reassemble. The aperture should be adjusted. The diaphragm of the FD 50mm 1:1.8 SC is different from most other FD lenses. It is not a separate unit but part of the inner lens barrel. The FD 50mm 1:1.4 SSC's aperture unit for example can be removed entirely from the front without opening the rear of the lens.

What is the serial number of the lens?

Possibly something is obstructing the aperture simulator lever when the lens is mounted to the camera. The aperture simulator lever is the smaller of the two levers at the rear of the lens, located at left-hand side when viewed from the rear. This is what I would check next: Is anything inside the camera obviously obstructing the travel of the lever? Does the camera's aperture signal lever move freely? The aperture signal lever is the one moving vertically at the right-hand side inside the camera mount: Remove the lens. Cock the camera. Engage the stop down button. Gently push the lever towards the bottom of the camera. There should be even and only light resistance along the lever's entire travel.

How do you test that? By pressing the stop down button and turning the aperture ring tof/5.6, f/8 etc? Or by chosing a slow speed or bright scene that would require the camera to use f/5.6 or smaller?

I remember the story of your lens. I have posted my 2 cents to the other thread. IMHO one would simply put the lens mount in a plastic box for disassembly in order to not loose any of the steel balls...

Are you sure it is blank metal? Oil entering the aperture unit can often be spotted first at the very outer edges of the blades and it is highly reflective as well. I have not worked on a 300mm 1:2.8 Fluorite myself. This is based on my general experience with servicing other Canon FD telephoto prime lenses: The lens mount assembly which contains the levers and ball bearings has not to be disassembled. The aperture unit will easily separate from the lens mount assembly. The aperture unit is accessed from the front. If it was my lens I would unlock the lens mount while the lens is off camera and work the levers. If I could sense abnormal resistance would take off the lens mount assembly for closer inspection. Otherwise I would give the aperture unit a good cleaning again.

I cannot tell for all FD lenses. But for the following list of FD lenses as of 1971 (so it's all very early FD lenses, note the missing "S.C." and "S.S.C." designations) the steel balls of both bearings in the lens mount are indentical: FD 17mm 1:4 FD 24mm 1:2.8 FD 28mm 1:3.5 FD 35mm 1:2 FD 35mm 1:3.5 FD 50mm 1:1.8 FD 50mm 1:1.4 FD 55mm 1:1.2 FD 100mm 1:2.8 FD 135mm 1:3.5 FD 135mm 1:2.5 FD 200mm 1:4 FD 100-200mm 1:5.6 The number of balls is different for each lens. Please note that there usually are a few balls less installed than the maximum number that would fit into the bearing. I cannot tell if the steel balls are interchangeable with later FD and New FD lenses. But I would assume chances are good that the steel balls are interchangeable at least between lenses of the same era. If I was in the need of spare steel balls I would just try with the cheapest junker of about the same age I could get my hands on. Are you asking about a specific lens?

Did you double check that the viewfinder display was not turned off unintentionally? The switch is located around the battery check button.

I would be interested in the literature. How can I be in touch with you?

Cannot give you complete instructions but here are a few things to try / watch out for: Make sure the mount is unlocked (as if the lens was mounted to a camera). Try moving the levers to a matching position when installing the mount. The lever in the upper red circle is moved by the cam of the large ring one of the "sticks" hooks into. The lever easily snaps "behind" the cam when the ring is rotated to far. Double check. The stop in the lower red circle is attached to the aperture ring. If it is in the way, set a different aperture.

You're right that all FD lenses should operate with your camera. I'd suppose that the lens aperture controls don't work properly which could prevent the release cycle from completing. Check if the mechanical lens controls work freely while the lens is not mounted to the camera. Remove rear cap, release chrome ring by pushing down the stopper that holds it in the unlocked position, then turn to locked position. You should now be able to freely move the automatic aperture lever and the aperture signal lever (the two levers running in the long slots). You should feel some resistance because the levers are spring loaded. But they should not feel stiff nor rest at any position.

You may have missed matching the pin at the bottom side of the AE mode selector with the slot in the actual AE mode switch during reassembly. Remove the release button and AE mode selector again. Try moving the switch (shifts left/right) with a small screwdriver or a pair of tweezers and check if the camera fires again. Switch to AV mode and reinstall the AE mode selector in AV position. Dirk

Canon New F-1 - Data Backs

No optics in the body hence no difference in image quality. Go for an F-1 if you need exchangeable viewfinders or focusing screens (the later one can also be had with an AE-1 Program), choice of spot, partial or spot metering (New F-1), faster motor drives (note that 5 fps Motor Drive MA would fit AE-1 Program), larger film magazine, shorter viewfinder blackout, better robustness or if you just like the sturdier feel (and sound) of a pro camera. Did you consider a T90 or even EOS film cameras? If your focus is on image quality you may be better off investing into good lenses. Dirk