calling on Wollensak historians to tell me what this is

[kymarto]

Hi folks,
I recently purchased a very strange Wollensak lens. It is a Velostigmat Focus Series VI 3 inch f2 lens is a Betax shutter, with the date Nov 21, 1922 stamped on the back. I know that a similar lens was asked about here by a friend some time ago.

This particular example is in excellent shape. The glass is basically mint, except for a bit of dust. The shutter is not working well, but that doesn't bother me since T works, which is the only speed I need. At first I thought that this might be some weird ur-oscillo lens, but it definitely has a flat field. An f2 lens at that time was quite an achievement I guess, considering their other offerings in the 20s and 30s. The elements are uncoated. The front lens group is fairly slim, but the rear group is quite thick, and has what appears to be a flat glass element at the very back. It's strange--not screwed in, but a proper element fitted with a standard slotted retaining ring.

It has (as compared to their later Oscillo lenses) a quite large working distance. I can mount it on a 25-55mm focusing helicoid and it will focus to infinity on my Nikon D800. It appears to cover at least 6x6, but I have not checked carefully.

Any idea at all about this? Series VI?? The only reference I have seen anywhere to a Series VI was a soft focus lens very early on.

In terms of performance the lens is quite glowy at f2, but already by f2.2 or so it has gained considerable contrast, and it is quite decent already by f2.8. It has very interesting sharp bubbly bokeh, but I hardly think this is a triplet. I'm posting a few shots so you can get a feel for what it does.

The first street shot is at f2.1 or so. This gives you an idea of the lens' interesting bokeh

The second shot of the flowers is again at f2.1. The bokeh is very nice IMO.

The third shot of cherry blossoms again at f2.1

The fourth shot of cherries is at f2.8. Already at that aperture the lens is getting quite well behaved for standard photography, still with a hint of bubble bokeh. These are all shot on a NEX-7 with APS-C sensor, however there is not much change in the character at the edges of full frame.

If anyone has any info or links on this lens please do pass them on.
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[luisalegria]

Sadly, I have little to add, other than I have heard of these before also.
Series VI seems to have been a "special" category, perhaps special orders, not usually with things listed in their catalog.

The old American aperture system would have had "2" corresponding to the modern f/5.6 (A lot of old Rapid Rectilinear "4" lenses are misunderstood, they are actually f/8!) and this was still in use in 1922, notably by Kodak. Still, your shots DOF look like your lens is a true f/2.

The Betax shutter (I have a couple) was something of a studio-type, limited to 1/100, oriented to slow speeds but very heavy duty, without the high speeds one would expect would be desirable with faster lenses outdoors. The Betax was pro equipment and fairly high tech in 1922, with a clockwork delay for accurate slow speeds.

There were fast shutters in 1922, the very common Compur of the day went to 1/250 in such a size, Compounds to 1/200, commonly used on what at the time passed for fast lenses. Wollensaks own top of the line Optimo went to 1/300.

The shutter may be a clue as to what its meant for.

Very interesting results indeed, and a very special lens.

[dan_]

[luisalegria]

A cine lens is a natural assumption.
But would these have been set in shutters, even at the time?
The use of studio-type shutters for these, in all cases I've heard of, points to, perhaps, an indoor application, such as in a laboratory.

[dan_]

[kds315*]

Show picture(s) of that lens please. I have an idea, but need to see it first...

[kymarto]

[luisalegria]

"I'm a bit puzzled by the "Focus" designation. I've seen it on other Wollies. What does it signify? "

Focal length.

This does not seem to be an Oscillo lens as seen in later Oscilloscope cameras, its probably too early for even the earliest CRT Oscilloscopes, but it could well have been intended for some similar purpose. Early X-Ray camera?

[kds315*]

Could be for a spectroscopic system as there is very little light, it had to be fast,
to record a spectrum on photographic plates. Just my guess....

I have similar from the 30s, super fast (for that time), made by Steinheil, a very fast
1.8/5cm (50mm) lens in shutter. http://macrolenses.de/ml_detail_sl.php?ObjektiveNr=343



Found later the documents for it. Looks like that:

[kymarto]

Yes, I guess it is for something like this.