100-400 with a converter

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Neil
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does any one use a 100-400 with a 1.4, or 2x converter?, if so do you still get reasonable quality, ie is it alot better than heavy cropping, or is it not reallyb worth the effort and expense, thanks for any advice
 
Not worth it with a 1.4x, definitely not worth it with a 2x.

You will get some people saying that AF will work with a non-reporting 1.4x TC, or with some pins taped. This is correct, if by 'work' you mean 'struggles to achieve focus, sometimes succeeding but normally giving up after a long period of searching'.
 
I have on my 1D Mark 2 with a 100-400 - 1 series retains centre point AF but my 40D doesn't.

If it helps - these are 40D with 2X on a 100-400

2434176320_61fb00c364_b.jpg

2433346003_b5ac000178_b.jpg



2434173578_9bb24d3ac6_b.jpg

2433354513_30ae2a2384_b.jpg
 
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I have used a Kenko pro 1.4x teleconvertor on my 40D, 5d2 and 1d3. In good light there's no problem with AF with the pins taped and using my 100-400L.

Sorry to disagree but I get very little hunting and AF is quick to lock on.

However I will state again that I use it in good lighting conditions. Once the light level drops more than a dull day then AF does stop, but then you can still use MF like I do in those conditions.
 
only the 1d series can af after f5.6 upto f8.
when the lens focuses it always uses its wide apature to focus then at the last moment stops down to what apature you have set, so if you have a 300mm f2.8 and stop it down to f8 focus the lens stays wide open f2.8 then when you press the shutter it stops down to f8, so with your 100-400mm it is f5.6 at 400mm so will af fine but if you stick a 1.4x tc on it will be f7.84 and when you focus it will only use f7.84 so wont work unless you have a 1d series.
 
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scottthehat said:
only the 1d series can af after f5.6 upto f8.
when the lens focuses it always uses its wide apature to focus then at the last moment stops down to what apature you have set, so if you have a 300mm f2.8 and stop it down to f8 focus the lens stays wide open f2.8 then when you press the shutter it stops down to f8, so with your 100-400mm it is f5.6 at 400mm so will af fine but if you stick a 1.4x tc on it will be f7.84 and when you focus it will only use f7.84 so wont work unless you have a 1d series.
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thanks for clearing that up, now i have a better idea.
 
Frank

The camera and lens communicate and one of those communications is which lens is fitted. Fitting a telecon and any lens slower than f5.6 on the XXD and XXXD range disables the AF on the camera.

So to get round this theres whats known as the taped pin method. This stops full communication between the lens and body fooling the camera into not knowing what lens is fitted.

This allows in good light lenses such as the 100-400L and 24-105L to autofocus correctly.

The ammount of light has to be good but I found with the 40D it would AF even on a dull day.


photo by Chris Hamlet, on Flickr

This picture shows my telecon with a little strip of sellotape over three pins, these are the lens communcation pins that tell the camera whats fitted.
 
Ah thanks Chris. I knew about the communication problem, but not the dodge. Ta muchly.
 
My 100-400L worked fine with a Kenko 1.4x and 7D combo without a tape mod. AF worked fine, image quality was okay, but teleconvertors are better suited to primes than zooms. The only zoom lens I have tried which gives good IQ results with a TC is the 70-200 F/2.8 IS II.
 
Orville said:
My 100-400L worked fine with a Kenko 1.4x and 7D combo without a tape mod. AF worked fine
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What, you could take decent pictures of moving things like birds in flight? Your 100-400 must be quite different from mine. I'd love to see these images.
 
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