# 100-400 with 1.4x teleconverter on crop body



## sedwards (Oct 20, 2014)

ive seen a few of you guys have posted pics using this lens combo on a crop body. are you guys using live view autofocus or manual focus ? how is it performing ? i have been thinking of getting an extender and i know the autofocus wont work unless using liveview but i would like some feedback on how it works in realworld conditions.


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## Mt Spokane Photography (Oct 20, 2014)

It works poorly, if at all. Don't expect good results with autofocusing, the lens may hunt, focus motor vibrate, or, if you are close to being in focus, it might snap into focus, or just take a oof image.

I'd say try a 70D with live view, or wait for a 7D MK II which will AF at f/8. It will be slower, but at least, the other issues should not happen. The 70D, and presumably a 7D MK II will AF at f/11 which means with a 2X TC.

Also note that third party TC's will have varying results depending on brand, model, and even within the same model (Kenko Pro DGX), there are different firmware versions that act differently..


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## Coldhands (Oct 20, 2014)

Here's one with this combination on my 7D. I took this mostly to satisfy my curiosity. AF was non-functional so I used live view MF. Even on my quite stable Manfortto 055 tripod the result is lacking sharpness, as it's difficult to keep a high shutter speed when shooting at f/8 (and you really want a fast shutter at 896mm equiv.!). It was also seriously lacking in contrast, and took a fair bit of processing to bring it back to life (hence the noise). Overall I wouldn't recommend this setup for serious work, but it'll do if you really have no other option.




Untitled by colin|whittaker, on Flickr


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## Canon1 (Oct 20, 2014)

This is a really poor combo even on a ff body that will AF at f8. The already slow AF performance of the 100-400 is made almost unbearable with the tc. It hunts, and when it does find focus the iq is just terrible. Your images will be far superior from a keeper and iq standpoint if you simply crop more in post. 

The tc does work ok on the 400 f.6, but just ok. AF is quite acceptable but iq is not super (better stopped down to f11) Plus without IS the SS has to be really fast.


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## 2n10 (Oct 20, 2014)

These were taken with my 7D on the 100-400 with a Kenko 1.4TC. You must use the outer 2 middle row focus points to get decent focusing ability. Focus is slower, you need greater light and contrast.


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## neuroanatomist (Oct 20, 2014)

I've used the 100-400L + 1.4xIII combo on my 1D X, and I'd call the IQ 'decent' but not great. Here are a couple of examples. I doubt I'd even consider ISOs this high on a crop body, even the 7DII.






EOS 1D X, EF 100-400mm f/4.5-5.6L IS @ 560mm, 1/320 s, f/8, ISO 5000





EOS 1D X, EF 100-400mm f/4.5-5.6L IS @ 560mm, 1/320 s, f/8, ISO 10000


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## Marsu42 (Oct 20, 2014)

2n10 said:


> These were taken with my 7D on the 100-400 with a Kenko 1.4TC. You must use the outer 2 middle row focus points to get decent focusing ability. Focus is slower, you need greater light and contrast.



Question is if at this magnification, you'd see a difference with a tc and the bare lens.

To the op: I've just got a 70-300L with the Kenko (you get a working but sloooooow f8 af), so take it for what it's worth - but it's about the same iq or even a bit better than the older 100-400L. Basically, forget about using this on a crop body, you're cutting 1.6x times 1.4x away from the glass and it really shows with these midrange lenses.

I only use it to zoom in on sunsets and the like nowadays that need even more cropping, but for anything that require sharpness it's not worth switching the tc on.


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## 2n10 (Oct 20, 2014)

Marsu42 said:


> 2n10 said:
> 
> 
> > These were taken with my 7D on the 100-400 with a Kenko 1.4TC. You must use the outer 2 middle row focus points to get decent focusing ability. Focus is slower, you need greater light and contrast.
> ...



I'd say the IQ is a little worse but definitely not killer loss up close. As the distance to target increases then the loss increases too.


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