Canon 300mm F4

[Alex90]

After months of deciding whether or not to get this lens i have finally gone and bought one! i opted for the Canon 300mm F4 L IS USM as opposed to the non-stabilised version.

My questions are, how does it perform with a tele converter 1.4 and 2? I presume it keeps autofocus with the 1.4 and loses it with the 2x?

I think in most circumstances the 300mm will be enough, particularly for the deer in the new forest, however i will need the extra focal length for other wildlife hence the teleconverter questions.

cannot wait to use it!

Any other hints/tips i could try with this lens please feel free to add

Alex

[slimrbp]

Hi,

Good choice it's the lens I currently use. It works well with a 1.4x, the autofocus is a bit slower but I think you still get good IQ, for bird phtography it pretty much statys on. With the low minimum focussing distance it makes a good lens for butterflies.

I have also used the 2x converter and you do lose 'normal' AF but if you have live view on the camera it may work. These are experiences:

300mm f4 L with 2x extender

Canon autofocus at f8

One not about extenders though, I tried the lens with a Kenko 1.4x but it didn't play well with the IS. I bought a Canon 1.4x and it works perfectly.
This shot was taken with the 300 with a 1.4x extender.

[squishy]

I'm wondering about this at the moment as well.

Got a bit of money to spend (), and I'm looking at the 300/4L.

One of the things that concerns me is the AF. Some people say it's fine with the 1.4, some people say it gets a bit slow.

I'll be interested to hear some more comments from users.

[slimrbp]

I guess it's another of those it's all relative I certainly haven't had any problems. It is a little slower in some conditons than the naked lens but I guess that is to be expected as you are getting less light.
But when I used the 100-400mm f5.6 I didn;t notice it being any quicker.

This was taken with AI servo using the 1.4x:

[glsammy]

Originally Posted by slimrbp

Hi,

One not about extenders though, I tried the lens with a Kenko 1.4x but it didn't play well with the IS. I bought a Canon 1.4x and it works perfectly.
This shot was taken with the 300 with a 1.4x extender.

That's interesting. When I had the 300mm F4, I used it with a Kenko pro 300 1.4x TC. The main reason I got rid of it was the poor IS and AF performance when used with the TC. Perhaps I should have tried the Canon one, as I had no problems with the image quality.

[slimrbp]

Originally Posted by glsammy

That's interesting. When I had the 300mm F4, I used it with a Kenko pro 300 1.4x TC. The main reason I got rid of it was the poor IS and AF performance when used with the TC. Perhaps I should have tried the Canon one, as I had no problems with the image quality.

It was a Kenko Pro 300 as well.

It was odd, the symptoms where a sort of 'bounce' when ever AI was acheived (really annoying in AI servo as it bounced whenever it got a focus lock). Also at narrower apertures it would 'bounce' when you took a shot. All this only with IS on.

[glsammy]

Originally Posted by slimrbp

It was a Kenko Pro 300 as well.

It was odd, the symptoms where a sort of 'bounce' when ever AI was acheived (really annoying in AI servo as it bounced whenever it got a focus lock). Also at narrower apertures it would 'bounce' when you took a shot. All this only with IS on.

Yep, that's exactly as I remembered it. I doubt I'll get another one now as I have the 400mm F5.6L which I'm very pleased with.
However I must remember the main reason I bought the 300mm in the first place, as a general all round lens capable of most subjects, including damselflies. The 400mm isn't due to its minimum focus distance of 3.5mtrs.
Having the 400mm F5.6 spoils you when you compare AF performance. Most other lenses seem downright lethargic in comparison.

[Michael A]

I have 100-400 and the 300F4, the latter i use with 1.4 converter and on the canon 7D find the combination gives good IQ and fast autufocus. On its own great close focusing for larger insects to get a bit closer i use 25mm extension tube. Main reason for using 300F4 and converter is weight when moving about although i always use a carbon tripod.

[glsammy]

I've started experimenting using extension tubes to allow me to use the 400mm for smaller insects. So far on the few occasions I've tried it it worked quite well.
Here's one I got earlier this year:

[BillyPilgrim]

It was a Kenko Pro 300 as well.

It was odd, the symptoms where a sort of 'bounce' when ever AI was acheived (really annoying in AI servo as it bounced whenever it got a focus lock). Also at narrower apertures it would 'bounce' when you took a shot. All this only with IS on.

I've been having exactly the same problem but I thought the lens was faulty.

I used to use a Sigma then Canon 1.4x and then got a Kenko Pro 300. Ive just tried it without the converter and the AF is fine.

Thanks for posting the above!

I think I'll put the Kenko on Ebay and replace it with a either a Canon or Sigma. If only I'd stuck with the Sigma in the first place...

As for the AF speed on the Canon 300mm. I noticed that it speeded up considerably when I bought my 1d body compared to how it performed on my 30d.