300 2.8 IS

[mike_tee_vee]

I've been yearning for more reach than my 70-200 2.8 and am contemplating the purchase of a 300 2.8 IS.  I read Bob's article where he switched from a 300 2.8 and 600 4.0 to a 300 4.0 and 500 4.5 for weight.  Would a 300 2.8 IS plus a 1.4 and 2.0 tele-converters yield an ideal balance between weight and focal length?  Sports and wildlife would be my applications for this reach.

Cost is another factor.  One of these fast telephotos is worth as much as my whole rig combined.  I estimate that I'd use the long end of the range for about 25% of my photography.  Should the cost of the components in your system commensurate with the amount of usage?  Any thoughts?

[Bob Atkins]

Opinions seem to differ on the quality of the 300/2.8L IS (or any other lens for that matter) with a 2x TC. Some say it's good, some say it's OK, some say it's a bit soft.

I know I wasn't really happy with the 2x on my 300/2.8L (non-IS), while others said that that combination worked well.

It would certainly be great if you could get a 300/2.8, 420/4 and 600/5.6 of excellent sharpness from single lens with 2 TCs, but I'm not altogether convinced you can. If you can rent a 300/2.8L IS and a 2x TC over a weekend it might be something to try before you buy!

An alternative might be a 300/4L IS plus a 1.4x TC. Cheaper and lighter than the 2.8. The 400/5.6L is great, but currently lacks IS. Whether an IS version will ever appear I don't know. It should (it's the only telephoto without it), but people have been saying that there should be an IS version for 10 years or more and there's been no sign of one yet!

[whizkid]

A pop photo monthly contest winner in the new Oct '09 issue has a shot of a white egret taken with a Canon 300 f/2.8 and 2x TC using a 40D at 1/60th . The reworked image evokes a bit of softness to me but it made front cover.  No mention of cropping degree. 

[marcfs]

I have a 300 f/4 IS and a 400 f/5.6 and shoot with a 40D and 20D.

Both lenses focus extremely fast and images are very sharp.  I do a lot of bird photography and when the 300 was my only telephoto lens, I used it with a 1.4 extender.  Generally good results with static images; slow/inadequate focus for birds in flight.  The 400 is excellent for birds in flight.  It is very easy to hand hold and images are tack sharp.  You need to have adequate lighting to hand hold this lens.

With newer camera bodies and ability to use higher ISO’s this will become a non-issue and the utility of the 400 will increase.  Bob could provide a comment on whether the higher ISO’s would also help the focus speed of the 300 and 1.4 extender.

Marc

[KeithB]

I am not Bob, but ISO has nothing to do with focus speed (except maybe when using LiveView with Contrast detection focus - Man, I hate it when they keep adding features - it makes for too many exceptions!).  AF is a completely independent system with its own sensors and even its own microprocessor!.

[Bob Atkins]

As Keith says, ISO setting and AF speed are not related.

A higher ISO setting can give you a few advantages that relate to this topic though. First you can use a slower lens, e.g a 300/4 rather than a 300/2.8. Second you can use a smaller aperture (e.g f8 rather than f5.6) which will give you slighly more DOF and thus better mask small AF errors.