I have 2 questions I guess. I was told that a IS lens could not be used on a tripod. Reason being the IS seeks to stabalize movement. If there is no movement on a tripod, the IS gets confused(?) and a blurry image is created. Sounds crazy to me. So, can one use a IS on a tripod? The other question is would you recommend the 100-400 IS over a 400mm fixed focus and why. I currently own a 300mm 4.0L and love it. I back pack often and know that the weight of a 400mm 2.8l is something to consider in comparison to the 100-400mm L. Ok, one more question, is the glass quality as good as the 400mm? Thanks

-- Melissa Hendricks (melissa@hevanet.com), April 04, 1999

Answers

Yes, you can use an IS lens on a tripod. Just turn off the IS feature when you do so.

Since you already own a 300/4, I'd suggest buying a Canon 1.4x to get your 400/5.6 lens. Quality is excellent, and the extender, while not cheap, if far cheaper than buying the 100-400 IS or a fixed 400/5.6 (much less a 400/2.8!).

UNLESS you really desire IS functionality in the 100-400 range, in which case the zoom's a sensible purchase. Even in this case, I'd recommend you consider selling the 300/4 and replacing it with the 300/4 IS (and extender) since it appears you are primarily interested in the longer lengths. That gives you prime lens sharpness at 300/4, excellent results at 400/5.6, and of course IS functionality.

Again, though, let me emphasize that there's no reason to buy an IS lens if you shoot off of a tripod most of the time and if doing so fits your shooting style.

-- Don Baccus (dhogaza@pacifier.com), April 04, 1999.

I have been using a 300mm L IS for about a year now on and off the tripod. Regarding the IS function on the tripod if you look carefully you will see the image frame "wander" when IS it tries to compensate for non existant movement. Without having got a sensible answer from Canon in Norway I deduce from this that when you go slower than 1/15th this is going to cause problems. I haven4t done any tests though and only use IS on the tripod if I am working fast hands on camera or if there is a lot of wind. Otherwise I stick to "conventional" methods......Mirror lock with the 2 sec timer is my favorite.

-- Scott Johnson. (Vitalh@online.no), May 29, 1999.