Canon EF 100-400 f/4.5-5.6 L IS

[Jonathan Farmer]

[center]Canon EF 100-400 f/4.5-5.6 L IS
VS
Canon EF 85 F/1.8

To those of you that are interested in how a Canon standard (not L) prime lens compares to a Canon L zoom lens, I conducted a few test shots using these lenses on the same seen and cropping out the centre/er and corner sections of the image at 100%.

The zoom was set at 100mm and the shooting point was set about 15 to 20 ft. back to try and scale the focal points so they appear more or less the same size, of course foreshortening was an issue so this was just a general procedure.

Some of you may think this test a bit unfair, but when you consider the pros and cons of both zooms and primes, the results are in my opinion interesting and surprising.

Two shots were taken with both lenses using apertures of f/4.5 zooms widest and f/22 primes smallest to measure sharpness in the center/re of the Rebel XTi’s 1.6 format and two other shots likewise were done to measure the sharpness of these lenses at the corner.

To keep a score or points, I created a scale of VERY GOOD (VG), GOOD TO VERY GOOD (G-VG), GOOD (G), SATISFACTORY TO GOOD (S-G) and SATISFACTORY (S). Please see below.

Centre/er

85mm Prime @ f/4.5 VG

85mm Prime @ f/22 (smallest) G

100-400 Zoom @ f/4.5 (widest) S-G

100-400 Zoom @ f/22 G-VG

Corner

85mm Prime @ f/ 4.5 VG

85mm Prime @ f/22 (smallest) G

100-400 Zoom @ f/4.5 (widest) VG

100-400 Zoom @ f/22 G

With these tests, the prime out performed the zoom slightly and bear in mind the prime was not used at its widest apperture, if I did not have a comparison to make, I probably would have rated all the images as VG. To say the prime is better as a whole would be unfair as the zoom is far more versatile (one lens covering 100mm-400mm) and in high contrast conditions chromatic aberrations are present with the prime and not with the zoom. The zoom on the other hand costs approximately $1400.00 where as the prime cost approximately $ 385.00.

The choice is yours but I must add, I am very happy with the results of the zoom.

Regards to all.

Jonathan Farmer

[Gidders]

Interesting comparison Jonathon, and the tests on www.slrgear.com show a similar story. Although the prime is not an L series, as it it stopped down 2 stops it is probably performing at about its optimum, where as the zoom at full open is probably not. At the other end, by f22 you are probably getting difraction setting in reducing

It would be interesting to see a comparison of both lenses at f8 which would probably show both at their best.

Also could you patch your crops together and post them so we can see thje results?

[Jonathan Farmer]

Hi Clive,

I will post them shortly.

Jon

[Jonathan Farmer]

Hi Clive,

All images are up with the information labeled in the names.