Canon EOS 400D / Digital Rebel XTi lens upgrade group test Cameralabs corner sharpness results

More results: Outdoor / Resolution / Corner sharpness / Fringe and macro / Geometry / Vignetting

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Canon EOS 400D / Digital Rebel XTi lens upgrade corner sharpness comparison

To measure and compare the corner sharpness of each lens using the Canon EOS 400D, we photographed the Enhanced Digital Camera Resolution Chart with each lens at its shortest and longest focal lengths using various aperture settings. The 400D was set to Large Fine JPEG mode and its Standard Picture Style. All four lenses were tested within moments of each other under identical lighting conditions.

The crops are taken from the lower left corner of the chart and presented here at 100%. The wide angle crops show a slightly larger area of the chart because the minimum focusing distances forced us to shoot from a little further away. No crops have been resized.

Zoomed-out to their widest focal lengths and with their apertures fully open, the budget EF-S 18-55mm again shows the weakest result of the group, although stop it down and it performs quite reasonably. The EF-S 17-85mm is also quite soft when wide open and additionally exhibits noticeable coloured fringing, geometric distortion and vignetting. There's also some vignetting with the EF-S 17-55mm when its aperture is wide open, but remember that's at f2.8. The effect becomes virtually absent at f4 and the lens delivers sharp and well-corrected corners throughout. The EF 17-40mm also performs well here, but we'd expect it to considering the lens is corrected for use on a larger full-frame camera.

Zoomed-into their longest focal lengths, the four lenses perform much more consistently in the corners, although again the budget EF-S 18-55mm is noticeably softer than the others. There's little to choose between the EF-S 17-55 and EF-S 17-85 models, although the former once again is impressive considering its f2.8 aperture. The only disappointment here is the slight softness of the EF 17-40mm corners at 40mm f4, as once again it should be corrected for a larger and more demanding full-frame sensor. In other tests with the EF 17-40mm though we've found it performs better at its wide-end.

Canon EF-S 17-55mm f/2.8 IS USM	Canon EF-S 17-85mm f/4-5.6 IS USM	Canon EF-S 18-55mm f/3.5-5.6	Canon EF 17-40mm f/4.0L USM

17-55mm EF-S at 17mm f2.8	f2.8 not available	f2.8 not available	f2.8 not available


17-55mm EF-S at 17mm f4	17-85mm EF-S at 17mm f4	18-55mm EF-S at 18mm f3.5	17-40mm EF L at 17mm f4


17-55mm EF-S at 17mm f8	17-85mm EF-S at 17mm f8	18-55mm EF-S at 18mm f8	17-40mm EF L at 17mm f8


17-55mm EF-S at 17mm f16	17-85mm EF-S at 17mm f16	18-55mm EF-S at 18mm at f16	17-40mm EF L at 17mm f16

Canon EF-S 17-55mm f/2.8 IS USM	Canon EF-S 17-85mm f/4-5.6 IS USM	Canon EF-S 18-55mm f/3.5-5.6	Canon EF 17-40mm f/4.0L USM

17-55mm EF-S at 55mm f2.8	f2.8 not available	f2.8 not available	f2.8 not available


17-55mm EF-S at 55mm f5.6	17-85mm EF-S at 85mm f5.6	18-55mm EF-S at 55mm f5-6	17-40mm EF L at 40mm f4


17-55mm EF-S at 55mm f8	17-85mm EF-S at 85mm f8	18-55mm EF-S at 55mm f8	17-40mm EF L at 40mm f8


17-55mm EF-S at 55mm f16	17-85mm EF-S at 85mm f16	18-55mm EF-S at 55mm f16	17-40mm EF L at 40mm f16

Canon EOS 400D / Rebel XTi lens upgrade results continued...

Outdoor / Resolution / Corner sharpness / Fringe and macro / Geometry / Vignetting

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