70-200 2.8 II with 2x (old) vs 100-400

[sanj]

Experts.
I have an unplanned trip to Masai Mara coming up with I am very excited about.
I sold my 600 ver 1 few months ago and have not been able to replace it (waiting for 200-400).

Now I have 300 2.8 ver 1 and 70-200 II for the trip. I am concerned that I might not have the required reach on my full frame cameras (X and 3).

A friend has 100-400 which I can rent for real cheap.

My questions: Will the 70-200 wit 2x be as effective as the 100-400 in regards mainly to IQ. AF speed is important by I think if there is any difference in this regard it would be minimal.

I intend to shoot at the widest f stop in most situations.

Thank you for your help.

Sanjay

[rs]

The 100-400 looks better at 400/5.6, but its not a huge difference:

http://the-digital-picture.com/Reviews/ISO-12233-Sample-Crops.aspx?Lens=687&Camera=453&Sample=0&FLI=5&API=2&LensComp=113&CameraComp=453&SampleComp=0&FLIComp=7&APIComp=0

Take your 300 and a TC or two along with the 70-200.

[sanj]

Thx much TC

[AlanF]

The 300 f/2.8 with TCs is much sharper than the 100-400mm. If you are going on a bird shoot on Safari, then I would definitely prefer the prime.  But, my experience from my one safari is that the zoom would be far more useful for the wild life as the game wardens take you very close to the big game and the 300 would be useless.  (I have both sets of lens and would pack the 100-400, which retracts nicely to a small size too).  On my trip, I had just the 70-200mm f/4 with a 7D, and that was fine for most of the time though double that would have been useful for some of the time.  Next time, it will be the 100-400 for convenience. 

[sanj]

The 300 f/2.8 with TCs is much sharper than the 100-400mm. If you are going on a bird shoot on Safari, then I would definitely prefer the prime.  But, my experience from my one safari is that the zoom would be far more useful for the wild life as the game wardens take you very close to the big game and the 300 would be useless.  (I have both sets of lens and would pack the 100-400, which retracts nicely to a small size too).

Alan good points. I have been to Sabi sands in Kruger before where we could off road and come real close to game. However this time I will be in main Masai Mara reserve and we are not permitted to off road. Game could be far or close depending upon luck but if far we would not be able to drive to them.

[AlanF]

Sanjay
I always travel light with just cabin luggage so the 100-400 is a must.  But, I would be tempted to take two bodies and both the prime and the zoom with a second suitcase.  The camera is important for the choice. My 7D was always a bit erratic with the 100-400 focussing. But my new 5DIII is superb.  This morning, I discovered from the FoCal website that they have tested both bodies with the 100-400 and found that the 5D III is excellent for that lens and the 7D is poor.

[sanj]

thx Alan