Does anyone know the type of cap that the Canon 35-70mm f/4 FD lens (New Mount) uses? I know it is a 52mm filter thread, but sources say that the lens orginally came with a slip-on cap that covered the lens barrel as well. What size and/or type (designation number) cap is it? And where could I find one? Thanks so much!

-- Joseph Wei (jimmy123ho@aol.com), December 07, 2001

Answers

Is that true? Usually the only New FD lenses with slip-on metal caps are the ones with built-in hoods and usually no filter threads (because there are drop-in filters like on the 300/4.0L or built-in filters as on the 7.5mm fisheye). I think the 52mm normal lens cap is it.

-- David Goldfarb (dgoldfarb@barnard.edu), December 07, 2001.

Your New FD 35-70/4 uses a W-62 hood. That might be the "cap" to which your sources refer. What are your sources?

I do not own this lens but I note from my literature (Canon "Lens Work," 1981) your lens (introduced June 1979 according to the Canon Camera Museum at http://www.canon.com/camera- museum/camera/lens/f_lens.html ) has no lugs outside its barrel to mount the newer type of hood. It's completely smooth on the outside for the last five or six millimetres of the barrel. In the photo, it even looks like it *might* be smooth on the inside for the last two or three millimetres. The photo seems to show the 52-mm filter threads begin that far down inside the barrel.

If this is the case, I guess you *do* need a slip-on cap because, it seems, a conventional 52-mm thread-gripping cap won't work Is this correct?

Unfortunately, I see nothing about the cap, itself. If I come across anything more, I'll let you know.

-- Robert Segal (robertsegal@juno.com), December 07, 2001.

Yes, the 52mm threads are so deep down inside the lens barrel (the elements/filter ring slide up and down as they zoom), so a thread- grpping cap wouldn't work - instead it would probably jam between the outer and inner barrels. I've found a cap at KEH that is called a 62mm Push-On cap, made by Canon. It does not say what lens it fits. Could that be the one?

-- Joseph Wei (jimmy123ho@aol.com), December 08, 2001.

I want to say "yes." Since the W-62 hood you'd use must get its name from somewhere, I presume (dangerously, perhaps) you would likewise require a 62-mm cap.

Very strange of Canon to implement such a scheme.

-- Robert Segal (robertsegal@juno.com), December 08, 2001.

I have this lens. It is a push on lens cap, internal diameter looks like 62mm, but there is no model/part number moulded onto it. In any case it isn't a terribly secure fit (mine at least) and I'm always paranoid about losing it when out, so if you need a lens cap you might want to investigate other possibilities. I've just had a try and a 58mm Canon cap just clips in but isn't a fantastic fit; as the aperture narrows slightly a smaller cap might be better but I haven't got one to try - just remember that when you zoom the lens, the cap may pop off. Alternatively, you could put on a filter and clip a 52mm lens cap into that as it will just protrude far enough at minimum focus at the 35 end, but this is more risky as, if you don't remember to remove it, it may disappear inside as has been said above.

-- Jeremy (bmjb@hotmail.com), December 08, 2001.

Hey, Joseph, just another thought: I, too have seen some Canon push- on caps that didn't have what it took to stay in place. I also have several Canon lenses with built-in hoods I prefered to augment (because the built-ins slide back in my bag, exposing the glass to my greasy groping fingers). On my 200/2.8 and 135/2.0, I have threaded- on metal hoods of appropriate extensions for those mid-telephoto lenses. If you acquired a 52-mm threaded hood just barely long enough to protrude past the end of the barrel, you could use a standard, 52-mm, spring-clip cap. Check for vignetting! You might have to chop down the hood a bit if you got a telephoto hood.

-- Robert Segal (robertsegal@juno.com), December 08, 2001.

Another option, particularly if you have the appropriate lens hood, would be an Optech Hood Hat. These are neoprene covers designed to go over lens hood instead of a lens cap. They are also nice replacements for FD lenses that came with "bag" covers instead of normal lenscaps. I use one on my FD 400/4.5 S.S.C.

-- David Goldfarb (dgoldfarb@barnard.edu), December 08, 2001.

Thanks to everyone who contributed their thoughts and advice. It is greatly appreciated. I now have a better idea of what to do to solve this lenscap problem. Thanks again!

-- Joseph Wei (jimmy123ho@aol.com), December 09, 2001.