I haven't done one of these for a while.  I worked on
these 5 images yesterday.  They were the result of 2
new-2-me antiques.  A 415mm f4.5 Voigtlander Portrait
Euryscop, and a 420mm f4.5 Voigtlander Heliar.

window sill ~ 42cm Voigtlaender Euryscop @ f4.5

The Euryscop is very unusual.  Anytime an Aplanat
(rapid rectilinear type) is faster than f6, it's gotten
into the highly irregular area.  They are extremely
uncommon.  Part of that may be that they ran
concurrently with the Heliar, an anastigmat.  Both
run side by side in my 1905 Voigtlaender catalog.

window sill ~ 42cm Voigtlaender Heliar @ f4.5

Both of them came via the Large Format Forum!
The big Euryscop is mentioned here, and the Heliar
turned up here.  Both owners were willing.

white porcelain white china ~ 42cm Voigtlaender Heliar @ f4.5

The Euryscop had a couple of serious flaws.  The
aperture looked like somebody had put their fist
through it.  Every blade was cruched and displaced,
and it had no flange.  Ouch.

white porcelain white china ~ 42cm Voigtlaender Euryscop @ f4.5

That gave extra impetus to obtaining the Heliar.
Since they were within 5 - 10 years of each other
in manufacture, I surmised (gambled) that it's
flange would be usable for both lenses.  I was right.

white porcelain white china ~ 42cm Voigtlaender Euryscop @ f16

Then yesterday I overhauled three 7 1/2" Packard shutters
one of which went behind these lenses with their common
flange.  These images aren't going to make my
name a household word.  But they do serve to
show what the differences might be for a portraitist.

So did Voigtlaender move forward, or backwards with
the introduction of their most famous anastigmat?