Цитата:от: Don_Pedro
Ну конечно, мне просто интересно, на сколько отличается первая версия. Нигде не видел сравнения side-by-side.
Академические
лейкодрочеры исследователи рулят:
6.8.9 2.8/90,Elmarit-R,1964
This first Canadian design for a 90mm lens for the R-system is an excellent
performer and shares by the way most characteristics with the Colourplan 2.5/90,
which is almost identical. A medium to high overall contrast is coupled to a very
even edge to edge definition of very fine detail, that is recorded crisply.
Figure 165: diagram 79
Stopping down slowly improves on this quality and at 1:5.6 a very high contrast is
reached with a clean recording of very small textural details over a large part of the
centre, falling off quite a bit in the outer zones. For best close-up performance one
should stop down two stops at least.
6.8.112.8/90, Elmarit-M, 1990 & 2.8/90,
Elmarit-R, 1980
In 1980 the Wetzlar designers recomputed the 2.8/90 for the R again and created the
best 2.8/90mm ever in the Leica history (R and M). The first series of the R-version
have been built in Portugal. The M-version arrived on the market in 1990, and is,
even today, one of the best lenses in the Leica M stable. We seem to have reached a
temporary platform here and while the new Apo-Summicron-M Asph indicates the
future direction as far as design methodology is concerned, an upgrade would not be
very cheap.
Figure 167: diagram 80
At full aperture, overall contrast is high and very fine detail is crisply rendered with
only a faint trace of colour fringing and astigmatism over the whole picture area.
The
previous R-version has lower contrast and softer edge definition and needs to be
stopped down to 4 to get comparable performance. At 1:4 the contrast improves
visibly and at 1:5.6 we reach outstanding image quality with extremely fine detail
recorded with high edge sharpness and good clarity over most of the image field. The
edges are slightly softer, but this will be visible only when one needs exacting
coverage of small details in the corners at bigger enlargements. After this aperture
contrast and edge definition drop due to diffraction. Close-up performance is as
good as at infinity. Vignetting is low with half a stop, and distortion just visible. Flare
suppression is excellent as coma (among others) is well controlled. As the 4 element
lens has no cemented surfaces, Absorban can not be used to control colour
transmission and it has to be accomplished with several types of coating layers.
Блахародная Германия против противной Канады короче.