I am looking into buying one of these lenses..

I am considering purchasing both and evaluating them. Both will be used outdoors with good lighting, probably wide open.

My questions.. 100-300mm/5.6L Is the autofocus that slow??

100-300mm USM Are the optics a big step under the L version?

what would you choose?

-- Pete (gregarpp@icqmail.com), May 07, 2002

Answers

The optics of the 100-300 F5.6L are generally regarded as being very good. The USM's optics are a step down. However, if you rely on AF to any real extent, then the USM will get you shot that the AFD motor of the older lens will be unable to get you. Better to have a softer shot than no shot.

Really it depends on what your priorities are. AF speed, go for the USM, optical quality go for the F5.6L.

-- Isaac Sibson (isibson@hotmail.com), May 07, 2002.

I guess I will have to see the AF speed hands on.

People have said the 50mm/1.8 has slow AF (I didn't think so)

People say the sigma 70-200mm/2.8 USM is slow (I didn't think so)

People say the 85mm/1.8 USM has quick AF (I didn't think it was much better then the 50mm/1.8 non-USM)

maybe it is just my subjects. Does the canon body make a difference in the AF speed (in minolta it is a big difference) I would be using this lens on Eos-3 and elan 7

-- Pete (gregarpp@icqmail.com), May 07, 2002.

Does the canon body make a difference in the AF speed

Absolutely. The two bodies you're using have pretty good AF systems in them. While the drive motor and the rest of the lens' design affect AF speed, it's the job of the body's AF system to figure out what needs to be done to get the image in focus and to direct the lens to do so.

-- Steve Dunn (steved@ussinc.com), May 07, 2002.

>100-300mm/5.6L Is the autofocus that slow??

Yes. I find this lens to be rather sluggish when it hunts. It's more of a problem than with a short lens like the 50mm 1.8, since on the telephoto lens you've got more distance to cover.

>100-300mm USM Are the optics a big step under the L version?

I think it's a noticeable difference, yes. The L lens is crisper and not as soft.

>what would you choose?

What's important to you? What are your priorities? The 100-300 USM is lighter, more convenient, focusses more quickly. The 100-300 L is heavier, longer, more of a pain to use and has better optics.

http:// photonotes.org/reviews/ef-lenses/

-- NK Guy (tela@tela.bc.ca), May 07, 2002.

My personal opinion only.

The 100-300L lens is considered a very good lens, optically. It is not very appealing when you consider the lens has a push/pull zoom, a rotating front element and filter thread, lacks FTM focusing, USM and is somewhat bulky. I would pick a more useful but less sharp lens. I did and bought the 100-300/4.5-5.6 USM. I don't use it much anymore but I was and am happy with the choice.

-- Lee (Leemarthakiri@sport.rr.com), May 07, 2002.

Pete writes, "People have said the 50mm/1.8 has slow AF (I didn't think so)...People say the sigma 70-200mm/2.8 USM is slow (I didn't think so)...People say the 85mm/1.8 USM has quick AF (I didn't think it was much better then the 50mm/1.8 non-USM)"

Pete, I agree with your assessment of AF speed on those lenses.

I once owned an EF100-300 5.6L USM and the optics were lovely. Even looking through the viewfinder you could see contrast and color were a cut above the crowd. My chromes sparkled like jewels on the light table. Everything was perfect except the dad burn lens racked back and forth a lot and was very sloooooow. If you shoot landscapes may not care. I would have probably kept the lens if it had a decent manual focus ring, but, unfortunately, it felt gritty and coarse making manual focus difficult.

Thus, I like the EF100-300 USM better because it always got the shot. The ring-USM rear element AF rips. However, I eventually decided that the apertures were too small on both zooms and use an EF70-200 4L USM and EF300 4L USM instead. I've been very happy with the performance and handling of this combo.

You topic has been a popular one for years and, thus, you can find many discussions about it on this board and many others.

-- Puppy Face (doggieface@aol.com), May 07, 2002.

Ihave arranged to get both of these lenses. I will be looking into an indepth review of the lenses on my website.

thanks everyone!!!

-- Pete (gregarpp@icqmail.com), May 07, 2002.