[Roy C]

Have any of you guys with f5.6 lenses with a 1.4 tc attached (un-taped) tried AF in live view on the 7D? I can get my 70-200/4 to AF with a 2x tc (Canon) un-taped.

[stu78]

Hi Roy,
Has the 7D got the same autofocus as the 50D in live view? I remember playing around with my kenko 1.4x and the 400 f5.6 untaped using contrast AF when I first got the 50D. Results were good but 3 or 4 seconds were needed to focus.
Here are two shots in my gallery that were taken this way.

http://www.birdforum.net/gallery/sho...7/ppuser/26729
http://www.birdforum.net/gallery/sho...1/ppuser/26729

Stu

[Roy C]

Originally Posted by stu78

Hi Roy,
Has the 7D got the same autofocus as the 50D in live view? I remember playing around with my kenko 1.4x and the 400 f5.6 untaped using contrast AF when I first got the 50D. Results were good but 3 or 4 seconds were needed to focus.
Here are two shots in my gallery that were taken this way.

http://www.birdforum.net/gallery/sho...7/ppuser/26729
http://www.birdforum.net/gallery/sho...1/ppuser/26729

Stu

Not sure about the 7D v 50D live view AF Stu. perhaps someone will tell us.

[IanF]

Interesting Roy. I've not tried it with an untaped converter.

I've been getting autofocus using live view with three teleconverters stacked with the 400mm f5,6. Not every time but more often than not. Using 5x mag seems to work best.

Even with one converter (taped and non-reporting) I can use the centre focus point in live view but have to use a corner one with the viewfinder - which is a little odd as they're all the same type of sensor points in the 7D.

A shame it doesn't work as well using just the viewfinder. I'm seriously considering getting something like the Hoodman viewfinder loupe and cinema straps.

[Roy C]

Originally Posted by IanF

Interesting Roy. I've not tried it with an untaped converter.

I've been getting autofocus using live view with three teleconverters stacked with the 400mm f5,6. Not every time but more often than not. Using 5x mag seems to work best.

Even with one converter (taped and non-reporting) I can use the centre focus point in live view but have to use a corner one with the viewfinder - which is a little odd as they're all the same type of sensor points in the 7D.

A shame it doesn't work as well using just the viewfinder. I'm seriously considering getting something like the Hoodman viewfinder loupe and cinema straps.

Its the difference between Contrast detection (live view) and phase detection (normal viewfinder AF) Ian. Apparently in phase detection the type of sensor matters whereas it does not in contrast detection. The downside to contrast detection is that is slower.
I can get my 300/2.8 + 2x + 1.4x tc to focus in normal mode because the camera only sees the 2x BUT the combo focusses better in Live view in my experience.
edit: I agree about 5x being better than 10x.

[Roy C]

I tried my 70-200/4 with stacked 1.4x and 2x tc's this morning (f11) and it did AF albeit rather slowly.

[NixAvianPix]

Sorry but what do you mean by 5x and 10x mag? Is this something within Live View? I have a Kenko 1.5x tc untaped with the 400 f5.6 but haven't tried using Live View yet on my 7D. Would you opt to use 2 sec. self timer if using Live View & tripod?

Thanks

Nick

[Roy C]

Originally Posted by NixAvianPix

Sorry but what do you mean by 5x and 10x mag? Is this something within Live View? I have a Kenko 1.5x tc untaped with the 400 f5.6 but haven't tried using Live View yet on my 7D. Would you opt to use 2 sec. self timer if using Live View & tripod?

Thanks

Nick

Yep, the 5x and 10x are zooms you can use when in live view, especially useful if manually focussing. Using a tripod is definitely an advantage when using LV as you will see from the amount of camera shake you get if you try to handhold. The 2 sec timer is also a good idea IMO (or a remote release).

[Boy George]

Originally Posted by Roy C

Yep, the 5x and 10x are zooms you can use when in live view, especially useful if manually focussing. Using a tripod is definitely an advantage when using LV as you will see from the amount of camera shake you get if you try to handhold. The 2 sec timer is also a good idea IMO (or a remote release).

Just to reinforce Roy's comment about using the 2 sec. timer - I've found it to be a most useful tip when hand-holding as, having pressed the shutter button, one can concentrate on holding the camera steady having eliminated any movement associated with that action.

Adrian