Telephoto testing: Canon 300mm with 1.4x and 2x TC's + Sigma 150-500mm

[micloi]

I did some testing today of the Canon 300mm 2.8 with both 1.4x and 2x Teleconverters and the Sigma 150-500mm OS.

Below is a summary of the results.

All were shot at a distance of around 10m or so. The I cropped a small piece of the photo (from the centre) and I enlarged all the crops to be the same size as the one from the 600mm shot.

Below is the link to the screen capture from Photoshop.
Where you see 300mm it is the crop from the Canon 300mm f2.8 IS, 420mm is the Canon with the 1.4x TC, 600mm is the Canon with the 2x TC and 500mm is the Sigma 150-500mm.

http://i387.photobucket.com/albums/oo311/micloi/comparisonall2.jpg

And here are all the individual images without any resizing:
http://s387.photobucket.com/albums/oo311/micloi/telephotos/

 

[HoppyUK]

I guess this is a kind of 'reach' test that birders like to see

If I'm reading things correctly, the Sigma is pretty poor, and the best result is with the 2x telecon, stopped down a bit. Ie in terms of IQ it is better to fit a higher magnification telecon than it is to just crop the image. And there's a reason why the Sigma is cheaper!

Certainly pulling that much enlargement straight out of the 300mm image is a big ask even from a 7D, so that's probably the finishing order you'd expect. Interesting to see though - that Canon prime is damn sharp, fantastic lens And it still retains AF even at 600mm. Thanks for taking the trouble

How does the AF speed compare between the various combos?

 

[micloi]

The AF with the 2x TC slows down a bit, but it is still pretty accurate. With the 1.4x I am sure there is a difference but I cannot really say that it affects me at all. The Sigma feels as fast as the Canon with the 2x TC (not too scientific but there you go!)

The Sigma is not bad at all for the money, but the Canon at 600mm wide open (f5.6) is still better than the Sigma at 500mm stopped down to f9 (as it should be as it costs 5 times more!!!)

 

[seltechpc]

Excellent series of tests. I did a lot of research before deciding on buying the 300 2.8, every time is see the results from it I am amazed. As Hoppy said it is one hell of a sharp lens.

I bought the Canon 1.4 and 2x telecons specifically for this lens and your tests have justified it I believe. It is the only lens I have that I would put a 2x telecon on as usually the images suffer.

Many thanks for taking the time to do these tests and put them on here.

Paul.

 

[AndyElliott]

Another thing worthwhile testing is picking a target where you can see the OOF areas front and behind. As well as a comparison of bokeh in general, it is worth looking to see if there is any bokeh fringing (longitudinal CA, green behind, purple in front). I say that because this is rather difficult to get rid of in post-processing. I have seen examples of the 300/4 +1.4 exhibiting this.

 

[micloi]

Another thing worthwhile testing is picking a target where you can see the OOF areas front and behind. As well as a comparison of bokeh in general, it is worth looking to see if there is any bokeh fringing (longitudinal CA, green behind, purple in front). I say that because this is rather difficult to get rid of in post-processing. I have seen examples of the 300/4 +1.4 exhibiting this.

That is an excellent idea, will do this as soon as I am back from my holiday (or even here, but I need to find a tripod that will hold 4kg!)