On Mar 8, 2005, at 4:01 PM, John Whittingham wrote:
I find these numbers mostly meaningless. The 24-90 is rated
"average", the 28-105 rated "good" ... sheesh, as if you can reduce
a lens' performance to one number and some meaningless one-word description.
I'd have to agree that there's much more to lens performance than an MTF
score and I think the "good" "average" etc. wording is pointless, but it's a
good scientific point of reference for resolution and contrast IMHO. If you
were to cross-reference MTF score with popular opinion of lenses tested you
should be able to come to some informed opinion of what quality you are
buying/using or at the very least what to expect.
Well, I don't even know what these numbers mean or what their sources are. The legend at the top of that page, http://www.photozone.de/2Equipment/easytxt.htm, states:
---
AF SLR LENS TEST GUIDE
The Lens Test Guide provides averaged lens ratings based on formal lens test results from various EXTERNAL SOURCES. Please be aware that naked test verdicts as presented below cannot describe all the different characteristics of a lens. You've to refer to test magazines directly for details. So please take these values as a tendency ONLY!
---
What are those sources? What are the testing methodologies? Where are the charts and specifications of the tests? ...
Godfrey
