Re: [Leica] Lens Tests?

["A.H.SCHMIDT" <horsts@primus.com.au>]

Steve LeHuray wrote:

> Nathan,
> Thanks for your reply, but, I would like to point out that I am learned
> enough to know that a comparison test between a Ford Mustang and a BMW M3
> the Mustang may go 0-60 faster than the M3 (but I doubt it) the M3 would
> most likey be the overall winner. To continue with this auto analogy; every
> Auto magazine in the world that does a road test or comparison test gives
> you a very detailed analysis of a car through the numbers (including
> reliability) so it is very easy to go through a number of road tets of the
> cars you may be considering purchasing and make your selection. So, you
> could say that this is "scientific" testing. And to the best of my knowledge
> every scientific endeavor from Anthropology to cancer to film emulsion to
> snow shovels to yacht design has some baseline numbers attached to it. And
> so, yes I have "invested" quite a bit of my time in the past year trying to
> get a grip on what Erwin is saying. And I have read everything Erwin has had
> to say on the LUG and the LHSA Viewfinder on the subject of lens design and
> its optical results and he is very adamant that his "scientific" testing is
> the superior method. So assuming that on a scale of 1 to 10 "extremely fine"
> is a 10 then where does "very fine" fit in? Is a "very good" a 4.5 or 6.3? I
> have been pondering these questions for some time now and so I wonder to
> myself "how does my Nikor 50mm 1.4 compare with my Summicron 50mm 2.0?" I am
> sure both lenses would get a "exteremely fine" rating but is the Summicron a
> 9.4 and the Nikor a 9.2 or vice versa? So, with all due respect to Erwin you
> are not going to find the answer on his website. Let me finish by saying
> that while my photo track record (pictures published) is excellent only
> because I have an excellent eye for composition, but, I am a real bozo when
> it comes to anything technical and that is why I am attracted to a baseline
> number.
> Steve
> Annapolis
>

Steve, What you say makes sense. But only if you get a list of numbers from each lens.

If every aspect of the lens is tested. say:

Vignetting wide open, 6.5,
Resolution  8.9
Contrast 7.5  etc.

This way you can select, what suits you best. However the overall rating with a number
is useless. You don't know which parameters where better and which where worse from one
lens to the other.
Back to your car analogy; In a sports car i am more interested in speed, in a limousine
in comfort.
Both cars may have the same final rating, but it doesn't mean anything.

Final ratings with .1 or .2 differences on a scale of 10 (that is 1 or 2 percent )
borders on stupidity. Totally meaningless.

Regards, Horst Schmidt