So, my recently acquired FD 400/2.8L's focus ring is stuck. Prior to this happening, there were a couple spots (150ft, and one closer to infinity) where it would "catch" sometimes. Now it's stuck between two hard stops (or sometimes just no rotation possible). Sometimes it comes free, randomly... but I can't reproduce that at the moment. Someone told me to check the manuals on using the pre-focus-stop mechanism - but as far as I know, all this lens has is the infinity adjustment ring. Which is also stuck between two hard stops, but with much more space in between those stops than the focus ring. I can't find any manuals on this lens, and can't seem to find any information in general about these lenses "seizing" like this. Does anyone have experience or expertise in this area? Does the lens need repaired? What could possibly be the issue? Thanks
https://www.butkus.org/chinon/canon/canon_fd_lenses/canon_fd_lenses.htm Few scanned PDF files related to FD lenses may not be as helpful as you need however.
https://www.mir.com.my/rb/photography/companies/canon/fdresources/fdlenses/400mm.htm additional info Found some forums mentioning that lens's focusing mechanism over the years getting a bit gummed up with age,it may need to be cleaned.
Thanks, I'm leaning towards that being the case (needing cleaned/repaired internally). I did look at the PDFs from butkus.org, but they are pretty general and don't include the super telephoto lenses unfortunately. Appreciate your help.
Welcome to the forum Derrick, I use a lot of and FL lenses and due to there age and the conditions they have been stored in, the oils dry up and it becomes hard to focus. You will need to strip the lens down and clean the moving parts with lighter fluid and wipe this off the moving parts, then lightly oil the clean parts with 3 n 1 oil, should be able to purchase this from super markets, it comes in a small tin and is used for lubricating sowing machines. Check out how to do this on You Tube, plenty of info on doing there.
Thanks Craig! So I actually got the focus mechanism free again... and discovered what the issue has been. Looking in the lens from the front, check out this photo: You can see clearly the loose washer and (foam?) piece that's supposed to be over that bolt on the side. So now my question is, do I still have to completely disassemble to access this area of the lens? Or is there a way to access by going through the front elements? I've watched some of the FD lens disassembly videos on YouTube - will this L lens be much different? Thanks for your assistance.
So I think I may have found my easy answer... I was hoping this type of disassembly was possible: https://translate.googleusercontent...L.html&usg=ALkJrhgpdvroAU6ykHxcFfSoA5PlXOk4Jw Link is to a translated page of a FD 300/2.8L fungus cleaning. After unscrewing behind the focus rubber, you can unscrew the front part of the lens. I believe this should be the same for the 400/2.8L. The whole front part past the focus ring can rotate a bit, so must be taking these screws out you can unscrew the whole thing. I think I will attempt and post back if it works.
Derick, you should be able to remove the glass elements, caution , those elements can be difficult to remove. I use a suction cup, the sort you get in a bathroom that has a hook for hanging things on. make sure it is clean so as not to mark the glass or scratch the coating . this will make it so much easier to remove, I use a white board marking pen (non permanent) to mark the order the elements come out in and go back-in the same order, it is easy to mix them up. Another thing to watch out for is if you are removing the lens's mounting end, there is a micro size ball bearing there used to make the aperture ring click, I have lost a couple of them, no matter how careful I have been they land on the floor and are eaten by a dust fairy never to be seen again. i now lay a white towel on my table, it does small objects such as springs and the previously mentioned ball bearing do not bounce and vanish the just sit there. Small screw should be laid out in the order they come out as quite often they a different sizes and will not go missing if placed on the towel. I have a few non working lenses and use them as spares. My I also suggest you buy a non working 50mm f1.8 as a source of spares bits, there are heaps of these lens around.so you may pick them up cheap. What tools do you use, I have a set of micro screw drivers, a pair of dentists picks, the type they clean teeth with, they have come in very handy especially when it comes to reattaching small springs. I also lashed out and purchase a good quality pair of tweezers, the cheap ones are useless. I also find invaluable a pair of magnified glasses, the sort they use in electronics. I am lucky, I have 20 20 vision but still need them. I hope this helps a little, can you show me some more images of the lens from different angles.
I followed the process from the translated link I shared above, and it was super simple and easy to reattach the washer and metal plate that was loose. There were 3 tiny set screws behind the focus rubber, and then you can unscrew the entire front of the lens. Here's a few photos:
Almost seems like a modular design where you could trade out the front element section for a different one. I know they did something like that on their older big telephoto lenses. I'm sure none of the newer designs would be this easy!
It was simpler than what I would have imagined,I have mainly the smaller lens sizes. if you are considering purchasing more FD lenses, try the 50mm F1.8. lens. There are heaps around and cheap.