[Leica] predicting lens performance

[Erwin Puts <imxputs@knoware.nl>]

Well Dan,

I am not sure what you are hinting at with this report. As you know 
very well, your paraphrasing of my lens reports might look funny, but 
it does not do any justice to the many hours of real testing and 
comparing results I invest in a real test.
As example you miss flare, close-up performance, the performance 
differences between the center and a series of locations in the 
field, the different levels of detail (from fine to extremely fine to 
on the edge of the films resolving power), the edge contrast, the 
astigmatism, color aberrations, decentring. The fingerprint 
differences when stopped down, the real optimum aperture, when the 
quality starts to become worse when stopped down etc.
Now for the record: my real report of a new Summilux will be vastly 
different from your projection. Let us make a bet and see which 
report is more closer to reality: your obvious extrapolation or my 
real work in some future date.
It is easy to say that the most current  lenses of Leica are better 
in contrast and rendition of fine detail than the older ones. As it 
is very easy to predict that a new car will have less pollution and 
will use less gasoline and will have better safety features. So 
testing is not necessary anymore? I will not buy a car that you have 
tested unseen on its braking performance in the wet, even if I can 
predict braking to be improved

If your method is so easy I suggest you ask for a position as chief 
tester at one of the major lens manufacturers. They could spare many 
man-years of testing real lenses after they employ you. You are even 
able to present the results of a lens that is not even designed. With 
such an ability you can  even become the editor of a nation wide 
photography magazine. They can dismantle their testlab.
Now for a real test as I like a challenge. Currently I am testing the 
new Summicron-R 2/180 and 2,8/180 APO. Now you tell this group your 
report of these lenses as that should be very easy for you to do 
(takes 3 minutes at most). In a few weeks (it takes me more than 3 
minutes alas) I post my real results. Then let us compare the value 
of your reports and let the group decide if my reporting has some 
added value.
Do you join me in this challenge, Dan?

Erwin