Canon 7D mark ii

[canonuser]

I am thinking to upgrade from 7D to 7D mark ii, but would like to know if 7D mk ii can auto focus on f8.
Can any one help me

Regards

[Warbler]

Only with the centre point, apparently.

http://www.dpreview.com/reviews/canon-eos-7d-mark-ii/6

I haven't tried it as I don't have a lens slow enough even with a TC attached.

[canonuser]

Thanks for that Wabler

[Mark L]

I am thinking to upgrade from 7D to 7D mark ii, but would like to know if 7D mk ii can auto focus on f8.

Did it work with the 7D? Why wouldn’t it work with mark ii?
Not sure I understand Warblers post?
Surely AF works across a range of apertures?

[Warbler]

To put it simply, auto focus works on the widest aperture of your lens. To acquire focus, the camera opens the lens' aperture to its widest. The aperture then closes down to your selected aperture value when you depress the shutter. If your lens has a widest aperture of f8, then all except the centre AF point on the Mk II are unable to get enough light to accurately AF. This is why you have a button on your camera that allows you to preview in the viewfinder what your selected aperture choice will give you. It will usually be darker than you're seeing through the viewfinder without the button depressed. It's called a "Depth of Field" preview button. No doubt the technical explanation will touch on the fact that you're looking through the lens when using your viewfinder, and it would be very dark indeed at apertures used by landscape photographers. So we're talking about maximum aperture values only. Sure we can stop down an f1.2 lens to f16 and still autofocus, but it is because the AF will use the f1.2 value to attain focus and the stop down to f16 when we actually take the photo.

http://photo.stackexchange.com/questions/5069/what-is-the-depth-of-field-preview-button-on-my-dslr-supposed-to-show-me




- - - Updated - - -

Here's a little more explanation. Wrong brand, but still relevant.

https://www.youtube.com/watch?v=k2G9...VAV1DkzDXlxIgp

[canonuser]

I am using 7d mki with canon 800mm f5.6 L USM lens, but can not use auto focus if I put a 1.4 extender on. I have to switch over from auto to manual to focus on the subject. I know that 5D mkiii and the 1Dx can auto focus at f8

[Warbler]

Have you tried the centre AF point? Does it not work with just that point?

[canonuser]

Centre AF point does not work for my setup, on the 7D mki

[Warbler]

You might need to give Canon a call. I'm sure they'll be happy to speak to a customer who owns a piece of glass like that. It's not as if you're a tyre-kicker. I didn't find anything in my manual about it. I suppose I could put both a 2x and a 1.4x TC on a lens and try it, but I don't know that that would be a useful test.

*****edit****

Never mind, I see you're talking about your 7D, not a 7D Mk II.

[canonuser]

Thanks for the advice. But i was wondering if the new 7D mkii can auto focus with the lens and teleconvertor

[Morgo]

7D MK II can AF at F8

I use my 7DII with a 100-400 II and 1.4TC III as a light weight option. Works quite well too.

I've tried my 600 f4 with a 2x TC as well and it also works fine though much slower to AF.