[Leica] Ultron and Color-Heliar

[Erwin Puts <imxputs@knoware.nl>]

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The Ultron 1.7/35 mm aspherical
A complex design with 8 elements, a negative front curvature and one 
aspherical curvature.
One half stop in between a 1,4 and a 2 design, this lens has the 
outward appearance of a older Leitz lens, the Tele-Elmarit from the 
sixties. At full aperure it gives a medium contrast image with a 
tendancy to flare. Very fine detail is recorded on axis with clean 
edges and in the field performance drops a bit and now fine detail is 
recorded with fuzzier edges. In the outer zones some astigmatism and 
color fringes lower the rendition of  the finer detail and outlines 
are fuzzy. The far corners are very soft and of low contrast. 
Outlines are visible and some detail detectable.
Some decentring is noticeable in the outer zones only. At f/2 the 
contrast naturally improves but not very visible, At f/2.8 we see a 
noticeable improvement in contrast and especially the aberrations in 
the field are reduced to a minimum. Extremely fine detail is now 
clearly detectable over most of the image field (corners still in 
worse shape) and at f/4 this level of detail rendition now is 
recorded with clear visibility. Edges stay on the soft side though. 
At f/5.6 the edges crispen and now we have the optimum with excellent 
recording of the critical 10 to 20 lp/mm . Close up at full aperture 
gives a faintly soft image and here stopping down to 4 is enough for 
really critical work.
This lens is clearly not ont he same level as the Summicron /35 asph. 
It is a match for the non-asph  Summicron 2/35 which has however a 
small edge in contrast and field performance.
The Color-Heliar 2.5/75mm.
A classical 6 element Double Gauss design with 6 elements in 5 
groups. It looks like an older Tele-Elmarit 90.
At full aperture we have a high contrast image with outstanding 
rendition of extremely fine detail on axis and  a  visible drop of 
quality in the outer zones where contrast drops, and outlines of fine 
detail become fuzier. Corners are very soft and of low contrast. At 
2.8 you do not note any improvement  and at 4 contrast improves. As 
with the Ultron the color fringes at the edges of outlines and finer 
detail structures do not disappear until 5.6, which is the optimum 
with an overall imagery of very high order; extremely fine detail is 
rendered crisply over the whole image field excepting the outermost 
corners.
Close up performance is Ok and on the same level as at infinity.
This general performance is comparable to the  older Tele-Elmarit 
2,8/90 and a class behind the current 2.8/90.
I also compared the Summilux 1.4/75, stopped down to 2,4 . Here the 
Summilux performs at ist personal optimum and we see exceedingly fine 
detail crisply rendered with high edge definition and contrast ove 
rthe whole image field. The Color-Heliar is a strong performer in 
itself, but the 2.5 performance is below the level defined by the 
Summilux-M.

A general assessment of all Voiglander lenses will follow. I have now 
tested and published about all lenses: 15, 25, 35, 50 and 75.

Erwin

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<fontfamily><param>Times</param>The Ultron 1.7/35 mm aspherical

A complex design with 8 elements, a negative front curvature and one
aspherical curvature. 

One half stop in between a 1,4 and a 2 design, this lens has the
outward appearance of a older Leitz lens, the Tele-Elmarit from the
sixties. At full aperure it gives a medium contrast image with a
tendancy to flare. Very fine detail is recorded on axis with clean
edges and in the field performance drops a bit and now fine detail is
recorded with fuzzier edges. In the outer zones some astigmatism and
color fringes lower the rendition of  the finer detail and outlines are
fuzzy. The far corners are very soft and of low contrast. Outlines are
visible and some detail detectable.

Some decentring is noticeable in the outer zones only. At f/2 the
contrast naturally improves but not very visible, At f/2.8 we see a
noticeable improvement in contrast and especially the aberrations in
the field are reduced to a minimum. Extremely fine detail is now
clearly detectable over most of the image field (corners still in worse
shape) and at f/4 this level of detail rendition now is recorded with
clear visibility. Edges stay on the soft side though. At f/5.6 the
edges crispen and now we have the optimum with excellent recording of
the critical 10 to 20 lp/mm . Close up at full aperture gives a faintly
soft image and here stopping down to 4 is enough for really critical
work. 

This lens is clearly not ont he same level as the Summicron /35 asph.
It is a match for the non-asph  Summicron 2/35 which has however a
small edge in contrast and field performance.

The Color-Heliar 2.5/75mm.

A classical 6 element Double Gauss design with 6 elements in 5 groups.
It looks like an older Tele-Elmarit 90.  

At full aperture we have a high contrast image with outstanding
rendition of extremely fine detail on axis and  a  visible drop of
quality in the outer zones where contrast drops, and outlines of fine
detail become fuzier. Corners are very soft and of low contrast. At 2.8
you do not note any improvement  and at 4 contrast improves. As with
the Ultron the color fringes at the edges of outlines and finer detail
structures do not disappear until 5.6, which is the optimum with an
overall imagery of very high order; extremely fine detail is rendered
crisply over the whole image field excepting the outermost corners.  

Close up performance is Ok and on the same level as at infinity. 

This general performance is comparable to the  older Tele-Elmarit
2,8/90 and a class behind the current 2.8/90. 

I also compared the Summilux 1.4/75, stopped down to 2,4 . Here the
Summilux performs at ist personal optimum and we see exceedingly fine
detail crisply rendered with high edge definition and contrast ove rthe
whole image field. The Color-Heliar is a strong performer in itself,
but the 2.5 performance is below the level defined by the Summilux-M. 


A general assessment of all Voiglander lenses will follow. I have now
tested and published about all lenses: 15, 25, 35, 50 and 75. 


Erwin 
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