I recently purchased on ebay what was described as a Canon 300mm/F5.6 lens.

However, when I look at the glass on the front of of the lens there is no writing whatsoever. All my other Canon FD lenses say something like "Canon FD 50mm 1:1.4 Canon made in Japan". Only the retractable lens hood says Canon on it. Also, at the camera end it looks square - like it takes square filters - something I do not find described for the Canon 300/5.6 lens.

Did Canon make all 300/5.6 lenses without the writing on the front? Is this a sign that the lens I have is not made by Canon? Is this a sign that the lens needed repair and the previous owner tried to fix it himself (and ruined the ring with the writing) rather than take it to a qualified repairman?

The auction seller is refusing to permit me to return it. I am trying to figure out what I got stuck with.

-- Howard Z (howard@howardz.com), February 17, 2001

Answers

It is probably a Canon lens. The built-in hoods aren't likely to fit anything else, and the longer Canon teles are often marked on the hood rather than with a ring on the front. Check this site for pictures that can help you identify your lens and the particular version you have.

If there is a rectangular mask at the camera end of the lens, that probably means you have an earlier version. The purpose of the mask is to prevent stray light from bouncing around inside the camera. Later versions use a round mask to allow for use with the 1.4x FD Tele-extender, which protrudes into the rear of the lens. If you have the extender, and it doesn't fit, it would be a simple job to have the mask machined to make room for it.

-- David Goldfarb (dgoldfarb@barnard.edu), February 17, 2001.

Neither my 300mm f/4 or my 200mm f/2.8 have identification on the front. They are both printed on the built-in hoods. My 100-300 zoom has an opening at the rear which is round, but also has rectangular corners, sort of like a circle overlaid on a rectangle. The rear element is recessed way up the tube. Is yours a breechlock or "bayonet" mount?

-- Alan Swartz (swartz@tyler.net), February 18, 2001.

It is the newer type - bayonet.

-- Howard Z (howard@howardz.com), February 18, 2001.

I also don't think anyone made an aftermarket bayonet mount lens for Canon FD. All the third party lenses have been pretty much breech lock.

I have several lenses that do not have writing on the front. Most because there is not enough room for legible writing. Look at the other markings, including the serial number. Do they look like the typical Canon markings?

-- Terry Carraway (TCarraway@compuserve.com), February 19, 2001.

You could also measure and weigh it. My listing shows the New FD (bayomet mount) 300 f5.6 lens to be 65mm x 198.5mm and to weigh 635 grams. It does have a built in hood and takes 58mm filters. The minimum focus distance should be 3 meters, and it should go to f32.

I doubt that any other lens would come close to the same specs.

There was only one version of this lens in New FD. In old FD there were three versions.

-- Terry Carraway (TCarraway@compuserve.com), February 19, 2001.

Well lens diameter is 2.5 inches, length is about 8.5 inches. It has bayonette mount. Says Canon 300mm 5.6 on the built-in lens shade. Goes to F32 Focusing range printed is 3 to 50 meters / 10 to 200 feet. Someone above said that some Canon telephotos do not have printing at the front lens element. Although it came with a 52mm lens cap, I find I can screw onto it a 58mm filter.

I'm starting to get a warm and fuzzy feeling that it is a genuine Canon 300mm/F5.6 lens. And $109 including shipping was an OK price.

Now I just need to buy a nice Heliopan UV filter and replace the 52mm lens cap with a 58mm lens cap.

-- Howard Z (howard@howardz.com), February 19, 2001.

Look at: http://www.mir.com.my/rb/photography/companies/canon/fdresources/fdlen ses/300mm.htm#f5.6 and: lenshttp://www.mir.com.my/rb/photography/companies/canon/fdresources/f dlenses/earlyfdlenses/300mmfd.htm for more info about the 300 f/5.6 fluorite

Rene

-- Rene Tielenburg (r.tielenburg@wanadoo.nl), March 17, 2001.