That would be nice, but is not likely to occur soon. Bad copies of lenses occur even with expensive Zeiss and Leitz lenses and it is a good idea to test one's own lenses with Imatest and compare the results with those reported by Klauss on Photozone.de. In a couple of hours, one can get a good idea of the performance of the lens at various apertures and focal lengths in the case of zoom lenses. To accumulate such data from photographic tests would take weeks or months of testing.
Bill
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Bill,
I agree that it's very unsatisfactory to be in a position where one gets an idea of the performance of a lens only after weeks or perhaps even months of use in the field. During such time, one might have taken a few lucky shots or a 'once in a lifetime' shot which is technically marred because one has used the lens at full aperture (for example), expecting it to be sharp because one had heard anecdotal reports on the internet that the lens
is sharp wide open. The fact that
your copy of the lens is not sharp at full aperture is a useful piece of information you've discovered in the field, and you have this once-in-a-lifetime, lucky shot to prove it.
If one is concerned about technical image quality, it seems to be necessary to always test a new lens one has bought before the expiry of the return period.
Now this testing process might be fun the first time and perhaps even the second and third time and, if one is particularly technically minded, it might be fun for the rest of one's life.
However, speaking for myself, I would rather pay an extra $100 or so on top of the normal price of a lens in order to know what I'm buying and in order to avoid spending probably considerably more than $100 worth of my own time testing a lens and possibly returning the lens, then testing the second copy and perhaps even returning that second copy before going through the whole process again.
In the recent past, I tested 3 copies of the Canon 10-22 zoom before I found one that autofocussed accurately and which was almost as sharp as my Sigma 15-30. (Finding one that was equally sharp might have been a never ending process).
I once spent the equivalent of more than a whole day testing the Canon 400/F5.6 prime. The time I spent included initial comparisons with my 100-400/5.6 zoom at 400mm; repeated tests because at first I couldn't believe that my zoom was sharper at full aperture and thought that maybe there was an autofocussing issue; processing such test images and burning to CD as evidence; driving back to the store to return the lens for another copy (a 2 hour drive since I live outside the city); returning without a second copy because the store didn't have one; (the salesman suggested he could send the lens in for calibration and if it wasn't improved then he'd give me a refund); repeating the testing procedure with the same lens after calibration, only to discover that it was still not as sharp as my zoom at F5.6, although slightly improved as a result of the calibration; another 2 hour drive back to the store to return the lens and collect my refund.
Geez! What a waste of my time! Now, to avoid impressions of exaggeration and hyperbole, I'll admit that the 12 hours of driving involved in this exercise cannot wholly be allocated to the decision to purchase this lens. When I spend two hours driving into town, it's for other purposes as well. I could have done all transactions regarding the purchase of this lens through Australia Post. Instead of a 2 hour drive on 6 occasions, it could have been a 20 minute drive to the nearest Post office on 6 occasions. Add the time spent unpacking and repacking the lens and the time spent chatting with the postmaster, that's probably a total of only 4 hours, not to mention the expense of fuel and wear & tear of the car.
The bottom line is, I spent more than a day of my life attempting to buy a lens that proved to be inadequate for my purposes, and I still don't have a copy of that lens because I'm reluctant to repeat this time-consuming and expensive process of testing.
Consider what could have happened in this case if all lenses were to ship with a comprehensive set of MTF charts. I'd walk into the store with a copy of the MTF charts relating to my 100-400 zoom. I'd tell the salesman that I wasn't particularly happy with the sharpness of my 100-400 IS zoom at F5.6 and that I'd like to check out the 400/5.6 prime which I'd heard is sharper and which I'd expect to be sharper because it's a prime lens.
The salesman removes the set of charts in an envelope attached to the sealed box containing the 400/5.6 prime. I compare the charts of both lenses at F5.6. Both of us can see that my 100-400 zoom is sharper, so I reject the lens on the spot. No need for 12 hours, or even four hours of driving, and a day of my life has been saved for more useful activities, such as expressing my views on LL .