100-400mm or 70-200m with 2x teleconverter? Quality and speed?

[HighOutput]

Ok, I ran into a situation while at a Nascar race recently. I was using my Canon EF 300mm f/4L IS USM lens for the race, but I needed a little extra to get close to the pit road, I used my 2x II extender but lost my autofocus features. I then switched to my 70-200mm F/2.8 L IS USM lens with the teleconverter and the autofocus worked with that one. The 400mm seem to be enough focal length for what I needed. Upon my return I was contemplating the EF 100-400mm f/4.5-5.6L IS USM Lens for theses outdoor fast action pictures, but would it be any better than what I already have? Would the image be clearer with the 100-400 than the 70-200 with the 2x? I would be at f/5.6 with the converter, but the 100-400 at longest, would be the same. So the only thing I can see being a factor is quality, speed and weight...is this correct? or should I invest in the 2x III?

 

[CAP]

I have used a 2x teleconverter on my 70-200MM L IS USM many times on my 1DX and it works great i do loose some things in image quality. But i best compare to my Canon 7D as it is likely closer to what you are using. On my 7D this set is not the best as AF is VERY jumpy and images tend to be soft at times. But the 100-400MM will all ways be better as it is not converted and is original so optical quality is Much Much better.

I might also recommend selling or trading your 300mm F4 L IS USM for the 400mm F5.6 L IS if you really need the reach.


PRIMES ALL ALL WAYS BETTER !!!!!!!

 

[robbins.photo]

Ok, I ran into a situation while at a Nascar race recently. I was using my Canon EF 300mm f/4L IS USM lens for the race, but I needed a little extra to get close to the pit road, I used my 2x II extender but lost my autofocus features. I then switched to my 70-200mm F/2.8 L IS USM lens with the teleconverter and the autofocus worked with that one. The 400mm seem to be enough focal length for what I needed. Upon my return I was contemplating the EF 100-400mm f/4.5-5.6L IS USM Lens for theses outdoor fast action pictures, but would it be any better than what I already have? Would the image be clearer with the 100-400 than the 70-200 with the 2x? I would be at f/5.6 with the converter, but the 100-400 at longest, would be the same. So the only thing I can see being a factor is quality, speed and weight...is this correct? or should I invest in the 2x III?

The 100-400 would naturally have better IQ than a 70-200 mm with a 2x teleconverter, however it will depend on the quality of the teleconverter as to the overall difference in IQ.

 

[DarkShadow]

Why not use the 300 F/4 with a Canon 1.4 TC and have the range you need, auto focus and the IQ.

 

[CAP]

Or get a 400MM f/5.6 USM then put 1.4x on it! NOW THAT'S A IDEA !

\:hail:

But a 300MM F4 IS USM with 1.4x is also a very good combo.

 

[Vince.1551]

I'll avoid TCs. IQ can drop 20-30%. Not good for cropping.

 

[Derrel]

I thought Canon's 70-200/2.8, the new Mark II L-IS USM, and NOT either of the earlier f/2.8 models. is supposed to be one of the absolute BEST zoom + 2x converter combinations on the market...and with their 1.4x converter, a very passable 280mm f/4 at the long end.

Still, I suspect the 100-400mm L zoom is, price-wise still a better deal than a $2,499 brand-new, current 70-200/2.8 Mark II PLUS a high-end Canon converter. The 100-400mm L has been around a long time, so there are PLENTY of them on the used market.

The 400mm f/5.6 prime has been shown to be better than the 100-400 zoom. Just. Better. Buuuut, it's not a zoom....

I suspect based on my Nikon experience, that Canon's 300mm f/4 + 1.4x TC to make a 420mm f/5.6 is as good as the 100mm-400mm zoom.

The thing is, with a 2x converter, a person loses TWO FULL EV worth of effective light-gathering power AND degrades image quality, so f/2.8 is effectively f/5.6 but with the image degradation that's present at f/2.8 or wide-open and, the degradation MAGNIFIED!!!!

I suspect, based on experience, that a good 70-300mm f/4~5.6 zoom lens can be optically superior to many more-expensive zooms with a 2x converter added to them. High-grade prime lenses, like a 300/4, or 300/2.8, or 200/2 with a manufacturer's 1.4x converter added to them however, can be pretty good for a lot of uses.

 

[HighOutput]

Theses are a few that I caught panning with my EF70-200mm f/2.8 L USM (non-IS) with my 2x II teleconverter. I added a little more motion blur to the background to make the car stand out a little more. I'm a big NASCAR fan, so I need a good NASCAR Lens.