Canon 100-400 f5.6L IS + Canon 1.4x Converter

rcmarple

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I'm an idiot.

Took delivery of a 1.4x converter to go with my shiny new £1000+ lens and guess what? I didn't do my research properly and missed the slight hitch of AF not working unless your lens is f4 or lower.

BUMMER.

Be warned guys and gals... :eek:
 
i only found that out after johndm posted a huge load of info about how it works


luckily i only plan on getting the 70-200f2.8L which is within limits



i thought it was above f5.8 on the lens, not f4
 
"The effective aperture of the lens is increased by one stop. Autofocusing does not operate if the effective maximum aperture is greater than f/5.6"

EFFECTIVE is the key word here which I missed. Effective means the aperture AFTER you fit the converter. On the 1.4, you lose one stop and on the 2x, you lose two stops.

So on the 100-400 f5.6L lens, the effective aperture is f.8 = no working AF.

STILL A BUMMER. :mad:
 
There are ways to get around this, notably taping over some of the pins of the tc to fool the camera.. but you'll get sluggish & unreliable AF in all but very good light. All in all you're better off without a tc on this lens.
 
rcmarple said:
I'm an idiot.

Took delivery of a 1.4x converter to go with my shiny new £1000+ lens and guess what? I didn't do my research properly and missed the slight hitch of AF not working unless your lens is f4 or lower.

BUMMER.

Be warned guys and gals... :eek:

Hey....we all make mistakes sometimes.... :suicide: The info is hard to digest when your all keyed up to buy.... :rotfl:

I was VERY strong today...while dragging my missus around Currys, she pointed at a LG 32" LCD telly, and uttered...'like that...its got a nice black surround....buy it'

I refused to get my plastic out...noted the model number, and am about to start gathering info on why the 42" Plasma is just so much better... :devil: :devil:

:hiya:
 
Pink Fairy said:
There are ways to get around this, notably taping over some of the pins of the tc to fool the camera.. but you'll get sluggish & unreliable AF in all but very good light. All in all you're better off without a tc on this lens.

In my experience the AF is totally unreliable using this method in even very bright light - it's totally hopeless. Image quality is also no great shakes when you add a TC to the 100-400.
 

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