[Klaus]

You are right, I have no doubt that the 17-40L is much much much better than a 17-85 IS!

(now)

 

But why do you all here stress vignetting, CAs and distortion that much? It is crystal clear being on the better site to take a good picture against having a poor one where software must help.

 

But vignetting and distortion (and with restrictions CAs as well) are issues where software can help pretty much.

I know the issues around my old lenses and correct them...

 

Okay perhaps I will see the difference when I took some pictures with the new lens and then I understand why my current are some poor undesirable looser lens are. :-)

 

I hope (but honestly I don´t think so).

 

Do you strongly disagree on my thoughts regarding software correction of optical issues (except sharpness)?

cu!

 

Martin

 

Software correction is mostly lossy. However, I have no problems with this per se. You just don't have 17mm anymore but probably something around 21mm if you apply distortion correction - thus the 17-85 deteriorates to a 21-80mm lens. Compensating the vignetting will increase the corner noise by 1.x stops.  The CA correction is lossless - no issues here.

Nothing can help you regarding the slight corner softness though (although the distortion correction may push the worst part out of the image field but then it's stretching & interpolating some other image portions making them worse).

 

If you are happy with the results from your lens, there is no debate anyway. Just live a happy life then. 

The reviews are meant for people out there choosing new lenses, not for reassurance. :-)