Hi--

>A year and a half ago, almost, I left Hewlett-Packard, and went to AT&T
>Labs. Our Internet access is kind of primitive here (even though
>Internet stuff is what we are supposed to be doing), and last I checked
>we could not post to Usenet news groups, so I've not been active in
>rec.photo. However, I just went browsing your web site and was really
>impressed with what you've got there.

Ah, I wondered what became of you! (The NG's have sure changed since you
were there...! Much less technical, and MT is gone, and in general,
there has been much less wrangling...[nothing to do with your absence!;-]).
Thanks for the comments on the web page! (I've been looking for free 8-megs
or so of space to put up copies of the 3K or so posts I've written
over the last three years....!!!!!) I've been more into digital video
this last year (three DV camcorders and a FireWire computer editing
system, whew...! ;-), so I write only on r.p.e.35mm and r.v.desktop,
and still spend WAY too much time doing it...

>Now, in June I was in Sweden. [......]
>This causes me to wonder about how to test lenses for flare. These
>tests could be either quantitative or subjective, I don't care (as long
>as you, or some one of your caliber, were doing the subjective stuff).
>Note that I'm talking about general scattered light, not necessarily the
>stuff that makes images of the diaphragm when you get the sun in the
>image. (I think these may be different mechanisms, I'm not sure, but
>they are certainly different effects.)

Yes - one I call "flare", the other "ghosting"... The problem for me
is that I'm not too concerned with flare if it is small enough to
not bother me too much in normal back-light situations (hard enough
to find lenses that easily pass this low standard!). I suspect that
all but a VERY few lenses would have problems in the situation you
photographed (and there may be no lenses that would do it well...).
Even the Tessars, with only two air spaces, generally don't perform
well here (though I could shoot into the sun with the Nikkor M
large-format lenses [tessar designs, but multicoated] with no ill
effects that I could see...). Some of the problem, BTW, is in the
camera body. Since the lens projects a circle (cut by the body),
surfaces of illuminated areas in the body need good anti-reflection
treatment. Also, a zoom may sometimes project a circle larger than the
optimum 45mm or so (as would PC lenses). (Actually, probably most
lenses project a circle larger than 45mm, especially at wide stops.)
A deep, custom rectangular shade should help some, but the optics
would still show some flare.

>One idea would be to lay some squares of black cardboard on a light
>table and photograph it with a constant exposure (if you know what I
>mean) for the light areas, and examine the film in the dark areas. For
>even higher subject contrast, the cardboard could be covered with black
>velvet.
>
>Comments?
David Jacobson

Um..., good luck? ;-)
Good to hear from you again!