Canon 100-400 II Vs 70-200 II f2.8 + 2x Teleconvertor

[YoshiK1]

Hello,

I found an interesting video on youtube about the title. The comparison photos between these lenses were almost identical but were taken on a 5DS at 50mp. The Teleconvertor was only used on the 70-200 f2.8. I want both lenses but never thought of this combination and the idea of having them both by using this combination and saving the money would be hugely beneficial.

I know with the 2x extender you lose 2 stops which isn't massive considering the 70-200 is f2.8 wide open for the full range. Canon advises this would ultimately become f5.6.

The thing I'm confused about is I've read that with the 5D MKIII you can only AF with the center point and it will remain a cross-type. I think it was 4 of the surrounding points will be useable but only through a area focus selection. Canon doesn't appear to have any of this mentioned in their manuals for the extender.

So I have a couple of questions here.

1 - What's your honest opinion about the lenses and combinations as mentioned above?

2 - Am I missing something here?

3 - Am I best to buy the lenses separately and keep extenders for larger lenses that I likely won't own?

Thanks

 

[lost]

Hi
I have both lenses and 2x extender. The resolution from the 100-400mm mkii is better than the 70-200mm f2.8 mkii fitted with the 2x extender in my eyes. Another area where the 100-400 seems better is in low light conditions the AF seems quicker. Another consideration is if something is happening will you have the time to fit the extender.
The main reason I bought the 100-400mm was for traveling I should add I have the 300mm f2.8 and 600mm f4 I.s as well so it was more of a considered buy than someone who buys something and tries to justify it afterwards. The main advantage of the 70-200mm with extender is you have a 70-200mm f2.8 for bad light and quicker auto focus with a 1.4 extender thrown into the mix you have a 280mm f4 lens again with the advantage in low light.
It's a horses for courses question I am afraid.
Regards
Richard
P.s
Just a thought a secondhand 300mm f2.8 mm I.s can be picked up for a couple of hundred pounds more than a new 100-400mm.

 

[Gaz J]

According to the 5D3 manual a 70-200 MkII a with a x2 fitted falls into group E which makes available all 61 points for focussing. Page 83 first column.