(Extracted from an article in the September 1982 issue of UK photo magazine
"Camera Choice".)
Since the introduction of the Olympus OM system some ten years or so ago,
the standard lens has been the 50mm f1.8, and a very fine one it has always
proved to be. Recently though Olympus made a few minor changes to it, and
for some reason this has created a lot of interest.
Manufacturers are constantly up-dating their products for a whole variety of
reasons. This may be because improvements become possible with advancing
technology, for production reasons, or simply because of a change in supply
of raw materials.
If a camera has a production run of several years, the insides of the last
samples off the line are going to be very different to the first. Much of
today's photography is bound up with electronics, and with the speed that
they are advancing, this year's latest wonder is old by next year.
So for reasons of their own Olympus made a couple of minor modifications to
their most popular lens. They didn't tell the world about it -- there
wasn't really a lot to tell. In view of the interest we decided to check the
old against the new and see just how they rate.
The New Standard Lens
There are a couple of cosmetic differences that allow you to tell which is
which. The old lens has the legend "F Zuiko" around the front element, the
new lens just says "Zuiko". The new lens tells you that it is "Made in
Japan" around the front element, while the old lens had that on the aperture
ring.
Two basic design alterations have been made to the new optic. It is
multi-coated, and instead of having 6 elements in 5 groups it has 6 elements
in 4 groups. Could that make any difference to the optical quality? It
seems doubtful, but we decided to check it out.
Under test we found, as would be expected, that the new model showed less
flare than the old.
The central definition was that tiny shade better on the new, but the edge
picked up the lost point on the old. But both were so close that it was a
real problem separating them.
Contrast of the new lens showed the traditional Olympus punch that we have
come to expect from the company. The same could be said about image
consistency, and the final quality rating was 39 points out of 50 -- the
same for both versions of the lens.
Conclusion
Frankly there was so little difference in the results that both sets of test
negatives could have come from the same lens. Which is no surprise because
in a way they did. There will always be very slight variations between a
group of optics from the same batch -- let alone from two designs. But the
differences observed are so small that a microscope (the "Camera Choice"
testing method) is needed to spot them. In every day practice they would go
unnoticed.
Olympus set out to alter slightly their 50mm lens design without making any
change in the optical qualities. In that they have succeeded (perhaps
better than they could have ever hoped), and have given us another lens that
will give exactly the sort of results that photographers look for.
Lens assessment (points allocated out of 10 for each parameter)
Lens Parameter Old Lens New Lens
Central definition 7 8
Edge definition 8 7
Contrast 9 9
Image consistency 7 7
Overall quality 8 8
Sum of the above 39/50 39/50
Lens Specifications
Old Model:
Focal length: 50mm
Aperture range: f1.8-f16
Closest focusing: 0.45m
Construction: 6 elements in five groups
Filter size: 49mm
Weight: 170gm
Length: 31mm
Diameter: 59mm
New Model (same as old model except for following):
Construction: 6 elements in 4 groups
Weight: 165gm
Length: 32mm
Diameter: 61mm
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