Focusing with the Canon 300mm F4.

[glsammy]

One of my main concerns with changing to the Canon 300mm F4 and using my Kenko 1/4X TC, was how the auto focus would perform, especially with birds in flight.
Today I had a chance to test the set up.

Here's a few of the shots I got.

Here's a Tufted Duck, flying towards me, often regarded as the hardest focusing test. The whole sequence was about 12 shots. Every one was in focus, even though I'd got the IS on the wrong setting.







Now a Canada Goose flew in. The bird wasn't very close, yet again the lens got the focusing spot on.







Now an even harder target, a Magpie, this bird was a long way off. These shots are 100% crops. Again I had the IS on the incorrect setting.










Considering I didn't manage to hold the bird on the centre focus point, the combination of the camera and the lens managed to hold the focus really well.

Overall I was very pleased with the outcome. There is some slow down on the continuous shooting speed when using the 1.4X, but the important point to me is that the accuracy doesn't suffer.

[galanthus]

Great pics Graham. I was considering the 300mm f4 and extender for some time, your pics may have just swung me around the the idea again

[zan]

yeah it's a good setup, and what I use for my "longer-range" shots, since I can't afford a longer prime. There is a noticeable slowing (especially wide open) like you say once the 1.4x is on, but I rarely take it off because the extra reach is worth a lot more to me.

It's a cracking lens - hope you enjoy it

[matt_xyz]

they look pretty good to me Graham. It would be interesting to see how that combo performs compared to the 400 f5.6.

Matt

[BillyPilgrim]

Some great shots there Graham. Unfortunately they've reminded me that I left my 1.4x converter in the hide at Bretton last Friday afternoon - DOH!

[galanthus]

Originally Posted by BillyPilgrim

Some great shots there Graham. Unfortunately they've reminded me that I left my 1.4x converter in the hide at Bretton last Friday afternoon - DOH!

Poor thing

[galanthus]

comparing that set up with the 400mm 5.6 wld be very interesting. Who's gonna try the shots ?

[glsammy]

I didn't get to try these types of shots while I had Rogers 400mm. I'm pretty certain the 400mm would have performed just as well if not better. As I said, there is a drop off in the continuous rate with the 1.4X TC on the 300mm. I can certainly accept that though, especially with accuracy like this.