About extenders and f/number limits for AF...

[antonroland]

Hello all

I have always believed that the scenario where AF wants f/5.6 or better (Landscape verticals on a 1D works at f/8 on the centre AF point, I know...) was also applicable to Nikon...have I been wrong?

Would like to believe not...

 

[DazJW]

A Google search brought up this page on Nikon's site which suggests it applies to their cameras too.

 

[antonroland]

Thank you!

 

[s162216]

Hello all

(Landscape verticals on a 1D works at f/8 on the centre AF point, I know

Unfortunately no longer with the new 1DX, apparently because of the new 'gapless' sensor AF will only work to f5.6 but autofocus overall will be better.

 

[scottthehat]

All nikon cameras will af upto f8,

 

[StewartR]

A Google search brought up this page on Nikon's site which suggests it applies to their cameras too.

Almost ... the key wording, however, is where it says that autofocus may not function if the maximum aperture of a lens is smaller than f/5.6. "May not", not "will not".

On Canon systems there is a firmware cut-off. All EOS bodies will AF with an f/5.6 lens but not beyond f/5.6; current 1D-series bodies will AF with an f/8 lens but not beyond f/8.

But Nikon systems don't have the firmware limit. So you're fine up to f/5.6, but beyond that it depends on the circumstances. Pro-spec bodies should generally be able to AF at f/8, but Nikon don't guarantee it. Consumer-spec bodies probably won't go beyond f/5.6, but Nikon aren't ruling it out.