no af with f4 lens and 2.0 extender

[ginger_55]

Rutt is letting me use his 2.0 extender for a short period of time. I am hoping to get some bird shots with it, or particularly, baby bird shots.

As one of it's features, it does not autofocus with lenses slower than 2.8. Mine is a 300L f4 IS USM. It is great with the 1.4 extender, just thought this would get me a bit closer.

Is this one of those things where people tape something, if so, what and how. Or should I just live with it for the short period of time I have it. I sure would not buy it for this lens. And, of course, I would like a faster lens. Got what I could.

Thanks, ginger

If this is in the wrong thread, you can move it. I am getting confused on some of these threads.

I can manually focus, did it for years and did not get one usable shot last night. The conditions were not good, though, and perhaps being too far away was a factor. I did use the monopod. My only problem with that was when I wanted to sit down and wait for the male osprey to come join the female.

[davev]

Rutt is letting me use his 2.0 extender for a short period of time. I am hoping to get some bird shots with it, or particularly, baby bird shots.

As one of it's features, it does not auto-focus with lenses slower than 2.8. Mine is a 300L f4 IS USM. It is great with the 1.4 extender, just thought this would get me a bit closer.

Is this one of those things where people tape something, if so, what and how. Or should I just live with it for the short period of time I have it. I sure would not buy it for this lens. And, of course, I would like a faster lens. Got what I could.

Thanks, ginger

If this is in the wrong thread, you can move it. I am getting confused on some of these threads.

I can manually focus, did it for years and did not get one usable shot last night. The conditions were not good, though, and perhaps being too far away was a factor. I did use the mono pod. My only problem with that was when I wanted to sit down and wait for the male osprey to come join the female.Hi Ginger.
I don't have your lens, but I do have a 70-200L F4.
I just re-bought a Quantaray 2x converter. With this setup, it will auto focus,
but not with the center focus point. (with a D Rebel)
The lens focuses fast enough for me to have all the points operational, and
recompose after focus is made.

This morning, I tried this setup, 70-200L F4, Quantaray 2x, and Tamron 1.4x.
Same thing. It wouldn't AF on the center point, but it really liked either one
right next to it. I think I'm going to play with this setup for awhile. It does
focus faster than my Sigma 80-400, but I lose the o.s. (stabilization)

The cheaper converters work pretty well, but you don't get that buttery
smooth background with them. Each converter costs around $80.
A person gains a lot of focal lenght for $160.

A quick one from this morning.
200 x 2x 1.4 x 1.6 = 896mm focal lenght.

http://www.pbase.com/davev/image/41872732.jpg

This is the pic right from the camera with just a resize.

http://www.pbase.com/image/41873598.jpg

[ginger_55]

Since all my parts, lens and extender, plus camera, are canon, I don't know how to compute.

Do you turn off the center? I use all of them, usually, I could turn just a side one on and see what happens. But FM's site did point out that it would not focus with a camera whose lowest aperture was higher than 2.8. Maybe that refers to the new ones, the EF 2X 11.

I will check at B&H. Thanks,


So far I am not thrilled, I got better photos with the 1.4 on the same lens. It was kind of a bad day (hour or two) all around. I couldn't get the male to show up. I think he was waiting me out.

Not that much to photograph, but it was depressing that what I did photograph was pretty bad. I should go out today, this afternoon, soon, and I don't feel much like it.

ginger