[Brightcolours]

Hello all,


something I do not understand regarding the verdict of the lens tests.


I got an offer to buy a pretty nice L lens from Canon and I compared those to my existing (much cheaper) lens. I found out the L lenses are much less sharper than my old ones, but the verdict says take the L and forget the old crap.


Ok, distortion and vignetting are bad compared to the new lens, end yes the old lens are  EF-S and the other one is a L. But for distortion and vignetting the camera and later Lightroom will correct this pretty fine - but the sharpness of the old lens is much better!!!


Why does the verdict praise the L lens and condem the EF-S lens?

Because its L and EF-S???


Any idea???



In detail:

"New Lens": Canon EF 17-40mm f/4 USM L

This lens makes most sense as ultra wide angle on full frame (5D, 6D, 1D). Not too much on APS-C, look for for instance a Sigma 17-50mm f2.8 EX DC OS HSM instead.

"Old Lens": Canon EF-S 17-85mm f/4-5.6 USM IS

A pretty undesirable lens, in my opinion. Strong CA, low contrast and a lot of barrel distortion at the wide end, and does not open much at the portrait end... Not a winner.

The advantages of each lenses are pretty clear to me… I struggle with the sharpness.

What are the advantages of the 17-40mm f4 on APS-C then?

Example values (all values taken from border at F/8):


17 mm

New: 1872

Old: 2057


24 mm

New: 1677

Old: 2167


40 mm (new) / 50 mm (old):

New: 1638

Old: 2167

You are comparing tests from an old and a newer camera body.

http://www.opticallimits.com/canon-eos/4...0d?start=1

http://www.opticallimits.com/canon-eos/4...0d?start=1

Compare these instead.

If I compare the values taken from centre the differences are much more.


Regards,

Martin