Can the Pro Nikon DSLR autofocus at f8

[USM]

I am very curious whether the Pro DSLR such as the D1x or D2H is still able to autofocus at f8 when you are using a f5.6 lens + 1.4x TC = f8.

Normally, the lens will not AF at f8. (Ignore the tape pin method)

On the contrary, Canon Pro series cameras (aka EOS 3, 1v, 1D, 1DII, 1Ds) are able to autofocus at f8 by using the center focusing point. So if you are using the 100-400mm f4.5-5.6 lens + 1.4x TC which is f8, you are still able to AF.

[espn]

I did a D1x + 300/4 + 2X TC = 600/8, it AF'd.

[jo3pit]

OT

i'm using d100 and a 400mm prime f/5.6 with 1.4X TC... no problem with AF
and the best part is.. it's still shows f/5.6 instead of f/8

here's a sample... where as i'm standing in front of esplanade. (orig img and uncrop)


Shutter Speed 5.000 s
Aperture f/25.0
Exposure Manual
Focal Length 400.0mm
Flash No

[USM]

Originally Posted by jo3pit the best part is.. it's still shows f/5.6 instead of f/8

I guess that you are using the Kenko 1.4x TC and not the original 1.4x TC-EII.

Kenko 1.4x TC is fully compatible with 70-200mm VR lens but not the 80-200mm f2.8D ED lens, meaning that the former will show you the correct aperture at f4 (a drop of a stop due to the 1.4x TC) while the latter will still show you at f2.8 despite the 1.4x TC mounted.

On the other hand, Nikon original 1.4x TC is fully compatible to the above 2 models, i.e. all will show you at f4.

[jo3pit]

Originally Posted by USM I guess that you are using the Kenko 1.4x TC and not the original 1.4x TC-EII. Kenko 1.4x TC is fully compatible with 70-200mm VR lens but not the 80-200mm f2.8D ED lens, meaning that the former will show you the correct aperture at f4 (a drop of a stop due to the 1.4x TC) while the latter will still show you at f2.8 despite the 1.4x TC mounted. On the other hand, Nikon original 1.4x TC is fully compatible to the above 2 models, i.e. all will show you at f4.

actually i'ts sigma 1.4x...

[icebooke]

No problems up to f/11.
f5.6 + 2x TC

[2100]

Well, ultimately it depends on the light levels and what you are AFing (contrasting edges), even if it works.

[aaronng]

I think it differs for each lens. On a wide angle lens, AF is difficult and is probably guaranteed at f/5.6 only because of the small difference in the out of focus and in-focus sections using phase difference detection AF.

But on long telephotos, the difference is much larger (that is why you get a blurrer background with longer lenses compared to short lenses at same aperture) and sometimes you can focus even at f/11 if you are near the subject and the focal length is long enough.

You can test by holding down the DOF button and trying to autofocus. I'm not sure if it works on the newer bodies, but it does on my F4.

Oh, and this is not Canon bashing, but on my friend's EOS3, as long as your lens + TC combo exceeds f/5.6, the AF is DISABLED. It doesn't even try to focus. That is one thing I like about Nikon.

[CAMEDIA]

Hi,

Thats cool for the pro bodies Wondering if anyone has tried the 2 below:

1) Breaking the f5.6 barrier with a D70?
2) Stacking Nikon 1.4xTC (modified) and a 2xTC and still achieve AF?

[mpenza]

with Canon bodies, you could AF at F8 with non-pro bodies by taping a few pins of the tele. not sure whether the same trick works for Nikon.

[USM]

Originally Posted by mpenza with Canon bodies, you could AF at F8 with non-pro bodies by taping a few pins of the tele. not sure whether the same trick works for Nikon.

If you are using the original Canon 1.4x TC, your tape pin method will not work at all. This method works if you are using 3rd party TC such Kenko or Sigma.

The question is even if your tape pin method does worked, the aperture will be still showing at f5.6 instead of f8 as far as EF 100-400mm IS lens is concerned.

Therefore, I am asking whether which combo will show you the exact f8 on the screen?

[AJ23]

Originally Posted by mpenza with Canon bodies, you could AF at F8 with non-pro bodies by taping a few pins of the tele. not sure whether the same trick works for Nikon.

Nikon bodies doesn't need that.

[aaronng]

Originally Posted by AJ23 Nikon bodies doesn't need that.

Yeah! f/5.6 is a given, and they let you try f/8 onwards because they know that if it works, it is a bonus and we will be happy!

[jo3pit]

Originally Posted by CAMEDIA Hi, Thats cool for the pro bodies Wondering if anyone has tried the 2 below: 1) Breaking the f5.6 barrier with a D70? 2) Stacking Nikon 1.4xTC (modified) and a 2xTC and still achieve AF?

camedia,

i've done it before (400mm 5.6 + 1.4X) AF still works all the way up to f/32...and max aperture still @ f/5.6 "no tweaks or tape method"

now your 400mm will become 840mm @ f/5.6

as for the 2x T.C (sigma) AF is disabled.

[Lunablur_Alaina]

I can focus with F100 with 70-200 Sigma with 2x x2.

[mpenza]

Originally Posted by jo3pit camedia, i've done it before (400mm 5.6 + 1.4X) AF still works all the way up to f/32...and max aperture still @ f/5.6 "no tweaks or tape method" now your 400mm will become 840mm @ f/5.6 as for the 2x T.C (sigma) AF is disabled.

focussing depends on the max aperture, not the aperture used lah....

[jo3pit]

Originally Posted by mpenza focussing depends on the max aperture, not the aperture used lah....

OT

oic... now i'm really enlighten.

thanks

[majere2sg]

Originally Posted by jo3pit camedia, i've done it before (400mm 5.6 + 1.4X) AF still works all the way up to f/32...and max aperture still @ f/5.6 "no tweaks or tape method" now your 400mm will become 840mm @ f/5.6 as for the 2x T.C (sigma) AF is disabled.

That will mean that the TC is not reporting the correct aperture to the camera. What if you try it on a f2.8 lens.. is it reporting f4 or f2.8 ?

[jo3pit]

Originally Posted by majere2sg That will mean that the TC is not reporting the correct aperture to the camera. What if you try it on a f2.8 lens.. is it reporting f4 or f2.8 ?

hmmm might be.... but i've done some test on f/5.6 & f/8 with same shutter & iso sensitivity.. and theres a difference in terms of exposure.

i've tested 70-200mm f/2.8 sigma hsm with 1.4x TC... max aperture was f/4