Telephoto prime or extender?

[AlQ]

Have the 70-200 2.8 and I'm looking at a prime w/ more reach (300mm), however cannot afford the New Canon 2.8 at 7k....300mm f/4.0 or 1.4 TC for the 70-200?

Thanks for feedback

[ceremus]

From what I've read the performance of the 70-200 2.8 II w/ 1.4 extender is very good. Although speaking strictly for contrast and sharpness, the 300mm comes out on top.

The Canon EF 70-200mm f/2.8 L IS USM Lens in combination with the Canon Extender EF 1.4x delivers an extremely versatile package of quality and features, but the 300 f/4 IS has better image quality (sharpness - especially in the corners - and contrast) at f/4 than the 70-200 does at 280mm f/4. Stopping down to f/5.6 greatly improves the combo's image quality but this costs 1 stop of light (allows 1/2 as much light to reach the sensor during the same amount of time). The 70-200 f/2.8 L IS is weather sealed - the 300 f/4 L IS is not. If you plan to primarily use 280mm or 300mm, the 300 f/4 IS gives you a lighter and less expensive package with better image quality. If you need 280mm only infrequently, then consider the 70-200 + 1.4 - or the Canon 100-400 L.

--Canon EF 300mm f/4.0 L IS USM Lens Review

So the extender combo will give you decent performance and more versatility for framing being a zoom lens, and the prime will give you better raw output.

Another thing to consider is you can get the 1.4 extender now and get the 300mm prime down the road and pair the two to give you a 420mm f/5.6 option.

[AlQ]

Thanks for the feedback...that helps me make the decision