Re: [Leica] Tri-ELmar report

[Erwin Puts <imxputs@knoware.nl>]

Report of the Tri-Elmar (#3753981) Leica code: 11890

This lens is very important in several ways. Its three focus (28-35-50)
selection brings zoomlike convenience to the M-rangefinder lineup. It takes
a while to become accustomed to its three ring handling (aperture
selection-distance selection and focal length selection). The focal length
selection ring is close to the distance setting ring and when in a hurry it
is easy to mix things up. After some use (it took me a day) your fingers
'know' intuitively the right locations. The convenience of having at swift
disposal three focal lengths would be useless for the critical Leica M user
if the optical performance would be blow par.
General optical performance.
I tested the 3E (My shorthand for Tri-Elmar)  in comparison with the 28
Elmarit-M current and third generation, the 35 ASPH and last non-ASPH
version and the current Summicron 50. As I always use the same test method
I can easily refer to the older generations as well.
First surprise: the 3E hardly improves on stopping down and this statement
is true for all three focal lengths. This behavior is only possible in a
very well corrected optical system. It also means that the 3E exhibits
excellent optical performance at its full aperture. Admittedly not as wide
as its fixed focal length brothers and sisters, but this issue we will take
up at the end of the report.
How excellent is the performance. Not every person will like the
conclusion, but the 3E is clearly superior in all optical parameters to
many Leica lenses of the 28, 35 and 50 focal lengths. With the exception of
the mentioned 5 lenses (28 current and 3rd generation, 35 ASPH and
immediate predecessor: (the 7 element Summicron) and the current Summicron
50) the 3E will outclass any other Leica lens of the 28, 35 and 50 focal
length of previous generations by a large margin.
Second surprise: its performance is in many picture taking situations equal
to the current Leica lenses of 28,35 and 50 type. There are obvious and
visible differences between the 3E and its current fixed focal length
lenses, however. To appreciate the importance of these differences I would
like to draw a distinction between  two types of Leica M users. The Heavy
Duty user who demands and needs the highest optical performance and has the
expertise to extract the full performance potential out of the Leica
lenses. And the Normal user who is quite critical in the performance area,
but whose picture taking style is a somewhat less demanding.
The performance of the 3E.
At 50mm:
the lens gives a high contrast image with fine and very fine detail detail
crisply rendered. Extremely fine detail has somewhat softer edges, but is
still quite visible. This performance extends over a circular  image area
with a diameter of 12mm (the center area). In the outer zones (the image
circle from 9 to 16mm from the midpoint) the contrast drops a little and
the very fine details become slightly softer. Some astigmatism lowers the
contrast here. The extreme outer area and corners are soft with fine detail
just visible. Stopping down to f/5,6 brings some what more contrast and
better defintion of extremely fine detail. This performnace level stays
till after f/11 where diffraction soften the deatils and lowers the
contrast.
Close-up capabilities (1,2 meter) are very good with a contrasty image
showing crisply rendered fine detail over the whole image field.
At 35mm:
at full aperture the contrast now is a bit lower and very fine detail is a
bit softer. Extremely fine detail is just visible in the center, but in the
outer zone barely so. The corners are on the same level as the 50 position.
Quite remarkable here is the uniform performance over the total image
field. The close-up performance again shows a high contrast image with
excellent detail rendition over the whole image field.
At 28mm:
Leica states that the 50 position of the 3E gives the best performance with
a bit less performance at the 28 setting. Indeed is the distortion a bit
more than at the 35 and 50 settings.When photographing flat objects like
walls, some barrel distortion is clearly noticably. When picturing
architectural objects with depth, this effect vanishes mostly.
At full aperture fine detail is rendered with medium to high contrast in
the center and drops a little in the outer zone. Very fine detail is
clearly visible and becomes somewhat softer in the outer zones.
At close-up distance the image is of the same high contrast and evenness of
field as as the other settings. Here as with the 35 and 50 setting stopping
down brings in contrast but the correction of aberrations is already on
such a high level that image details and textural details only improve a
little.

Comparison to the fixed focal lengths.
These lenses excell of course with excellent to superb performance at the
wide apertures of 2,0 and 2,8. At f/4,0 they are at its optimum and then
meet the 3E also almost at optimum performance. For all focal lengths we
can give this verdict. Based on the f/4 performance. The fixed focal lenses
outperform the 3E in the image quality  at the level of extremely fine
details and the performance in the outer zones and extreme corners. The
overall contrast of the ffl's too is better, giving the pictures slightly
more clarity.
Very carefull comparison of the pictures (low speed transparancy at 30 x)
taken with the 3E and its companions shows these performance differentials
in contrast and the quality at the level of extremely fine details.
The 3E shows remarkable suppression of flare and night shots taken on the
28 position give very good clarity of highlights and shadows with good
detail rendition and only a faintly visible coma in the extreme outer zone.

For the Normal user the performance differences are immaterial and will not
be of any importance. The HD user might note the differences but it is a
matter of personal preference  how to rate these quality differences.

Conclusion.
Is the 3E a replacement for three topclass focal length lenses.  The answer
is obviously not easy. Its full aperture of f/4,0 has its limitations.
especially when using low speed films. It design parameters define as a
worthy alternative in a compact body for 3 popular focal lengths and here
it performs outstandingly well. The smooth  and quick changing of focal
length brings many picture taking opportunities that are lost when you have
to change several lenses . And the critical Leica user can use these new
possiblities in the secure knowledge that the resulting pictures will show
all the qualities Leica lenses are famous for nowadays.  And she may even
smile broadly at all users,even the most critical, who are using the older
generations of Leica lenses in the 28 to 50 class. He is using a 330 grams
convenient optical system with excellent performance the older lenses
simply can not match. The modern and current generations are able but hard
pressed to surpass this level of performance at f/4,0 and smaller. The
Leica user who needs outstanding performance at apertures wider than f/4,0
and/or big enlargements showing the smallest  image detail with great
clarity and contrast needs to change lenses and wear out her bayonet
flange.

Erwin