1.4 teleconverter for a Canon 300mm f4

[Ken_Bower]

I am thinking about getting a 1.4 tele for my 300mm f4. Has anyone used a tele with this lens? Is the autofocus much slower?

thanks,

[Roger Clark]

Ken,
Yes, I have this lens and use 1.4x and 2x TCs. They work well. AF is always a little slower when adding a TC. Unless you are tracking very fast subjects, it still works well.

Roger

[Deborah Harrison]

I tried this combo with a rented 300 f4 and found that it depended on what body I was using. I had no problem with my D3, however the autofocus was somewhat sporadic using the 300S. This might have been the lens and not the combo but I suggest you test it out.

[Ken_Bower]

Thanks for the info. I'll be using it on a 50D.

[Danny J Brown]

Hey Ken:

I use the Canon 1.4x TC on my Canon 40D bodies with the 300/4 L IS all the time and it works great -- tack sharp, including birds in flight. It doesn't affect the 300 any differently than it does my 500/4 where it resides, by the way, about 90% of the time. You will love the new combo.

DB

[Christopher C.M. Cooke]

Ken I have used that combo on my 350D, 30D, 450D, 1DMKIII, 7D, 5DMKII and 1DMKIV and it is still one of my favorite and most useful lenses.

If using it for distance images of moving birds it always helps tp "Pre Focus" the lens first then it will AF quite quickly enough on most bodies, AF and IS can be a bit noisy, don't let it worry you.

The real joy of this lens is its versatility as it is close focusing and I often use it with tubes for brilliant Macro work.

[Kaustubh Deshpande]

Ken, I used to have the old non-IS 300 f/4. It took 1.4x pretty well. But depends on what you want to do with it. AF, especially with a 50D, will not be good enough for birds in flight. If you are interested in shooting static subjects, AF is sufficiently good with the 1.4x. One big advantage is the MFD. With tc, you increase focal length without compromising on the MFD. Hence, the 300 f/4L + 1.4x is a good setup for dragonflies and such. Because of the compression, DOF and field-of-view, it gives unique look to flower shots as well. If you are not into BIF, I'd say go for it.

[Danny J Brown]

Ken, I used to have the old non-IS 300 f/4. It took 1.4x pretty well. But depends on what you want to do with it. AF, especially with a 50D, will not be good enough for birds in flight. If you are interested in shooting static subjects, AF is sufficiently good with the 1.4x. One big advantage is the MFD. With tc, you increase focal length without compromising on the MFD. Hence, the 300 f/4L + 1.4x is a good setup for dragonflies and such. Because of the compression, DOF and field-of-view, it gives unique look to flower shots as well. If you are not into BIF, I'd say go for it.

KD - maybe works better with newer, IS version because as I said above, I have lots of excellent birds in flight shots with mine, especially eagles.

DB