Roger Skully's recent post was right on. As mentioned in an earlier post I
discovered some Olympus Newsletters from '73-'78. The newsletters were
edited by John Barras Walker, a Canadian Pro with credentials and awards a
mile long. I'll qoute his answer obtained via Olympus and his own testing
and verification. The quote is from the April 1975 newsletter.
MULIPLE COATING
This question crops up so many times from OM-1 owners and prospective
owners along the lines of "why don't Olympus multi-caot their lenses?"
They do! And - they don't say much about it.
There's nothing new about multiple-coating at Olympus, just as there is
nothing new about it at other precision microscope manufacturers such as
Leitz and Zeiss - Zeiss of course introduced lens coating in the late
'30sand moved into multiple coating during the war years.
Multiple coating has been carried out by better lens manufacturers for some
considerable time, in extra high speed lenses, and also to maintain colour
balance through a series of lenses in a camera system. In more general
recent use it was a technical innovation in the aero-space programme for
multiple windows of spacecraft to cut down flare when shooting through them.
"Flare conscious?"
What about flare - the reason for multiple coating? It is light bounced
around from the surface of lens elements that degrades the image by veiling
it and lowering the contrast. It happens more usually with lenses made of
glass of lower refractive index. Move the designs into the use of more
expensive high refractive index glass and we're in a different flare park.
This is what prestige lens designers have done. But flare is not just a
problem of lens glass, reflections are not just from lens elements, but
from the interior of the lens mount, from shiny lens diaphragm blades, from
reflecting surfaces in the mirror chamber of a sinle lens reflex. So,
Olympus have paid particular attention to lens barrel interiors, and you'll
note that the sides of the mirror chamber in the OM-1 are serrated like an
old bellows camera - old timers often mention that flare didn't seem to be
much of a problem with bellows cameras, of course not, bellows are the best
reflection absorbing feature in camera design. They could have used
sprayed-on black flocking which is also excellent, but feared that time
would make it an interior dust hazard, both from its collective properties
and possibility of deterioration.
Olympus frankly don't seem interested in using multiple-coating as
promotional wahoo, they tell us that they've been designing and making fine
optics for 60 odd years and design and make the best lenses possible - that
we can't argue with, independent tests bear it out. We do know, however,
that the 24mm and 35mm f/2 high speed wide angles are multi-coated, so is
the 16mm f/3.5 because of their highly complex construction. We suspect a
couple of others. Meanwhile I remain very, very happy with the performance
of my own OM-1 lenses, and rate them the best I have used in 25 years of
equipment testing, which, incidently has shown that multiple coating does
nothing much about reflections in some lens designs where strong backlight
gives reflections of the shape of the lens diaphragm, all any
multiple-coated lens of such design will do is give a sharper and more
contrasty reflection, - use that lens hood.
Multiple coating in the finder system is why OM-1 viewing is so bright.
End Quote.
I think Barras Walker's statement about "promotional wahoo" says it all.
And this was 25 years ago folks!!!!!!!
Time to go take some pix.
Barry H
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