1.4 TC III vs 60D, Is this test accurate?

[Nate]

Hi,

I am shooting on 5D3 with a 70-200 2.8 II and wanted a little bit of extra reach.

I checked this test with more settings but always the 1.4 TC III is way better than the 60D

http://www.the-digital-picture.com/Reviews/ISO-12233-Sample-Crops.aspx?Lens=687&Camera=453&Sample=0&FLI=4&API=1&LensComp=687&CameraComp=736&SampleComp=0&FLIComp=2&APIComp=0

This is surprising for me. I do not have any possibility to test, but somehow I still think that the 60D/7D + 70-200 2.8II, will make sharper images over 5D3 + 1.4 TC III + 70-200 2.8 II.

(please stick only to this two options and only at which would give sharper image, not AF speed and stuff like that)

-Nate

 

[Mt Spokane Photography]

A given lens will always appear sharpen on FF than on a crop camera. Check all the lens review sites. Even a 5D classic will produce sharper images than the best Canon crop.

DXO also has a useful function where you can see this easily.

Check it out on different bodies, the score is always higher on FF for a given lens.

http://www.dxomark.com/index.php/Lenses/Camera-Lens-Database/Canon/Canon-EF70-200mm-f28L-IS-II-USM/%28camera%29/176/%28cameraname%29/Canon-EOS-5D

 

[Loswr]

...somehow I still think that the 60D/7D + 70-200 2.8II, will make sharper images over 5D3 + 1.4 TC III + 70-200 2.8 II.

Sorry, but you need to rethink that...

 

[YuengLinger]

Well, we do lose a stop, right? I guess the OP believes the 1.4 TC III reduces sharpness slightly...?

 

[Loswr]

Well, we do lose a stop, right? I guess the OP believes the 1.4 TC III reduces sharpness slightly...?

We don't really lose stop in practice, no. An f/2.8 lens on APS-C gives the same DoF as an f/4.5 lens on FF (for equivalent framing). Since the FF sensor gathers more total light, the ISO noise is 1.3-stops less (assuming no significant difference in the underlying technology), so the stop lost for exposure (shutter speed) can be more than compensated by bumping up the ISO (and if you make up just that one stop, the noise will actually be less on FF).

The 1.4x TC does reduce sharpness, when comparing bare lens to lens+TC on the same camera. But when comparing FF to APS-C, the difference is greater than when comparing bare lens to lens+TC on the same camera, for the best lenses (poor lenses take a differentially greater IQ hit with a TC).

 

[Nate]

Very interesting, but it makes sense. I will go to the local store and try it out.

Maybe I will upload the test-shots here.