I am new to photography and I am looking at buying a canon 75-300 USM LENS but I am not sure what the difference between a 75-300 USM, 75-300 III USM lens, and a 75-300 III lens. The prices seem to range anywhere between $20 an $50 difference. Any help would be greatly appreciated.

-- Duane M. Farley (dfarley4@yta.attmil.ne.jp), May 12, 2002

Answers

The 75-300 USM first came out in 1992. Then in 1995, Canon came out with the 75-300 USM II, and this is wbat Canon had to say about the USM II at their website:

"In response to the great popularity of the original EF 75-300mm f/4.0-5.6 USM lens Canon has developed a more affordable alternative. The new EF 75-300mm f/4.0-5.6 II USM lens offers virtually all of the outstanding features of the earlier model, including compact size, light weight and high performance as well as a wide range of focal lengths-from medium telephoto to telephoto. What has brought down the cost of this new model are the refinements in the materials used for certain mechanical parts, changes to the micro ultrasonic motor drive circuitry, and a revamping of the entire production process. Substantial economies in these areas mean that Canon's superior optics and advanced autofocus technologies will now be available to a much larger audience of EOS SLR users."

Then Canon came out with the 75-300 USM III that, as far as I can tell, is identical to the 75-300 USM II except that it adds "a metal ring at the front of the zoom ring to give it an upscale image."

The 75-300 III is the non-USM version of the 75-300 USM III. It uses a DC motor, which means that the autofocus is going to be noisier than USM. By the way, the 75-300 USM and USM III use Canon's micro-USM, not their better and quieter ring-USM. Micro-USM is still quieter than a DC motor, though.

I would go with the least expensive USM lens.

-- Peter Phan (pphan01@hotmail.com), May 12, 2002.

I agree with everything Peter said, except I would opt to save the few bucks with the non-USM version since the micromotor USM used only offers a quieter focusing. There is no real speed gained and you don't get FTM with it like you do with the 100-300 USM.

I guess that's why Canon offers the choice. Nobody agrees on everything. :~))

-- Jim Strutz (j.strutz@gci.net), May 12, 2002.

I'd pay a little more and get the EF100-300 4.5-5.6 USM. It has rear element focus rather than front element extension, ring-USM, FTM, and a distance window. In other words, it focuses much faster, can be focused manually without touching a switch and polarizers are easier to use than the 75-300 models. Some claim it is optically a bit better. In my experience, the 100-300 has much less pincushion distortion at the long end.

-- Puppy Face (doggieface@aol.com), May 12, 2002.

Yeah, and I agree with Puppy Face too. The 100-300 USM is a much better handling lens. But while we're spending more of your money, I'd opt for the 75-300 IS, since it offers image stabilization for sharper hand held pictures.

I just wish I could make up my mind who to agree with more. :~))

-- Jim Strutz (j.strutz@gci.net), May 12, 2002.