EOS Lenses Having IS

Since 1989, I've been using Canon cameras as tool for my professional works. And just early last year that I was able to acquire an EOS 5 as an addition to my Canon arsenal. For a time now I was contemplating to buy some lenses and got a little worried about buying lenses having Image Stabilizers for a few reason:

1.IS lenses, as I know uses some form of gyro to compensate the movement & shakes we make; with these in mind will it not become a source of problem in the future since it is a precision device and will affect the image adversely if it breaks down?

2. Last January at Photoworld Manila '99 I was given a chance to get a hold of 300 L 2.8 on my EOS 5 courtesy of Canon Philippines and was surprise about its accuracy and speed but got a kick on my butt because it drained my newly installed battery. Is that a fact, that these lenses will take its toll on your battery?

I hope someone will answer me as soon as possible

Alvin: Are you sure you don't mean the 300/4 IS? I own this lens,

and have been highly impressed and satisfied with its astonishing

performance and sharpness. Like any other piece of sophisticated,

precision camera gear, the possibility always exists for problems to

arise. Otherwise, there would be little need for warranties and

repair facilities. My lens has performed flawlessly under heavy use

from the day I brought it home. As for battery power consumption,

well of coarse an IS lens will consume more power in IS mode than when

IS mode is switched off. I use a 1n powered only by lithium 2CR5s,

and I will frequently follow/track a subject for well more than a

minute at a time with IS, autofocus, and in-camera meter consuming

power all the while from a single 2CR5. It is difficult for me to

accurately recall and quantify the resulting increased battery usage,

but in general, I find that a useful approximation is to assume a

minimum of 50% more power consumption when IS is being used heavily

(as I have been doing) as compared to when no IS is being used but one

is still engaging the autofocus and metering systems for long periods

while doggedly following/tracking a subject prior to making the

exposure. I find that it is wise to double the number of spare, fresh

batteries that I keep in my bag when using IS heavily. On a vacation

or other extended foray, I would overcompensate and bring even more

batteries just to be safe. In my experience, typical day-to-day HEAVY

use of IS will NOT drain a fresh 2CR5 in minutes, hours, or even days,

but rather in about 1-4 weeks! If you cannot afford the relatively

modest increased cost of the extra batteries needed to support an IS

lens, then you may not be able to afford the lens itself in the first

place. And remember, there are very few free lunches--IS capability

offers extraordinary possibilities, but more electrons are part of the

price one must be willing to pay, in order to play.

Addendum: Of coarse, a more costly but ultimately more economic

solution is to invest in an attachable power booster for the camera

body, complete with quickly recharging and interchangeable energy

cells. The initial investment here is considerable, but would pay for

itself in the long run.

While on the subject, I'm interested in the new 500 f4 IS. Has anyone

had any experience with this lens and how is it's power consumption?