I really like this extender, yes it is not the same has having a 400mm but it gives you the flexibility that I want.I use it with my 70-200 2.8 II and it works great.If you need a dedicated 400mm then just buy that, but if you want the flexibility of once in a while converting your 70-200 to a 140-400 or whatever other lens you want to use it with, then this is a great solution.I would definitely recommend it to a friend!

Gives me the reach that I was expecting from my 70-200 but I have to consider what I am filming as you loose a few stops of aperture and the focus is "sluggish". It does a great job for moving targets that don't change speed quickly and have a predictable trajectory. I've used this to film lacrosse games and it's a lot of work getting the shot because of the slower auto focus.

I use this set with two Canon 1Dx with a 70-200 and 300mm lenses. Previous I used two separate Blackrapid slings which worked well but this distributes the weight better. It’s comfortable to wear for hours at a time without biting into your shoulders.

Very happy with the results. I added the extender to my Canon 70-200 2.8 lens and shot a soccer game with it. Great results. I didnt really see any slow down to the autofocus. It did push me up from 2.8 to 5.6, so more than the 2 stops I thought it would go to - but on a sunny day outdoors, it didn't impact me.

I got this lens a while a go...the first copy was defected but the second one was the right one....is very sharp considering that is not L series...but the focusing system is very fast...I can focus almost instantaneously...is fantastic considering the fact that is 4-5.6 lens....for everyday shots is very good...I was debating between the version of 70-300 L and this one and I'm glad that that i choose this one...considering the price.... now compared to the 70-300 Nikon version is faster and sharper without doubts,, i have Nikon and canon full frames and regarding to the 70-300 range...this canon beat the Nikon one....for sure...

Canon Ex-2X extender Excellent extender for the fast 2.8 Canon 70 to 200 lens. Great to hand hold and get sharp images, with proper camera uses.

Worked well with my Canon 70-200 2.8 IS lens on a recent African Safari.

I picked up the 82mm for my 24-70 2.8 and I got used to it and loved it. When I went to use my 70-200 2.8 without this VND for a surf shoot, I almost got sad at how different and negative the affect of not having this filter was. So here we are picking up my second and it's a great investment in a quality product that produces amazing photos!