I am a novice photographer and have recently purchased a canon. However what I ordered was the rebel 2000 kit and the vendor sent me a canon 300 with a 7 year warranty. I also purchased a EF 100-300 USM lens. It is made for canon but the brand name is Ultrasonic. Is that a dependable brand? I am also interested in purchasing a 2x teleconverter. Please answer as quickly as possible. I leave for Alaska next week and I'm debating whether or not I should return this camera. Thanks

-- zandra m. cantu (zcantu@yahoo.com), July 13, 2001

Answers

Zandra, the EOS 300 is the european version of the (US) rebel 2000. As far as I know these cameras are exactly the same, except for the name. The lens has "ultrasonic" on the front, that's just the canon way of letting you know that it uses an USM motor. I bet that the name "Canon" is printed somewhere near the mount, near the lens release button. You can probably use the lens with any converter, but be aware: you will lose autofocus.

-- Jos van Eekelen (jos@compuserve.com), July 13, 2001.

The Rebel 2000 is the North American designation for the EOS 300. Same camera, no difference except the name. Still the seller should have told you that you were getting the gray market or international version that supposedly doesn't come with the official Canon USA, one year warranty. Actually Canon will usually fix them under warranty anyway if you save the receipt. The 7 year warranty is of dubious value and is only as good as the company doing the work.

If it says "Ultrasonic" around the lens barrel, you got the real Canon EF 100-300 USM. USM stands for Canon's UltraSonic Motor (for faster/quieter focusing). No one else uses that designation for lenses.

Canon's own 2X TC won't work with your lens so you will have to go with a third party TC. Kenko, Tamron and Sigma all make them, as do others. Generally you get what you pay for with teleconverters. If you really want a 2X TC then make sure you get one with 7 elements in it. They really are better.

Using a 2X TC will reduce your lens to f/11 at the long end and it will not autofocus. Also the viewfinder will be dim enough to make it hard to manually focus as well. If you use a 1.4X (or 1.5X) TC you will end up with a 420mm (or 450mm) f/8 lens. The camera manual states that that is too slow to autofocus, but if there is enough light and contrast it probably will anyway. The optical quality of the 100-300 USM (and almost all other lenses in this catagory/price range) is not the best at the long end. A 2X TC will just magnify the softness of the image to mostly unusable levels. The 1.4X TC (usually 4 elements) will do the same but just not as much. You still need to stop the lens down to get usable images though.

-- Jim Strutz (j.strutz@gci.net), July 13, 2001.

Sorry, I was mixing up the 100-300 USM and the 100-300/5.6L. The rear element of the USM lens will conflict with the protruding front element of the Canon teleconverters. You will indeed have to use 3rd party converters.

-- Jos van Eekelen (jos@compuserve.com), July 13, 2001.

Before buying a teleconverter to go with this lens, you may want to read why you don't want to do this --> http://www.photo.net/photo/nature/telezoom+TC

-- Steve Dunn (steved@ussinc.com), July 20, 2001.

Contrary to above postings, even the 100-300 F5.6L is not compatible with the canon Teleconverters. The only zooms which are:

Canon 70-200 F2.8L USM Canon 70-200 F2.8L IS USM Canon 70-200 F4L USM Canon 100-400 F4-5.6 L IS USM

The following lenses may be thought by some to be compatible, but they are not:

Canon 80-200 F2.8L Canon 35-350 F3.5-5.6 L USM

As to the original posting....The stuff you have is canon, and put away any thoughts of a 2x TC on that lens. There are no short-cuts to long lenses. You'll loose AF, it will be too dark to focus, and the quality will be very poor also.

-- Isaac Sibson (isibson@hotmail.com), August 03, 2001.