[LargeFormat] Wollensak Extreme Wide Angle Lenses

[Clive Warren]

At 08:48 21/04/2003 -0600, Tim Atherton wrote:
>Hi Clive,
>
>Mine is coated for one thing - as I understand it the little pink @ sign
>(with a w inside) = "Wollcoated" - Wollensak's trade name for their single
>coating, as well I can pick up the tint of the coating in the reflections.
>
>Also, the 12.5 is no harder to focus, because it actually opens up to f9 (or
>wider). Or at least my version in the Rapax shutter does. When it's opened
>up to 12.5, you can see that the aperture is nowhere near fully open. You
>just remove a tiny retaining screw and it allows the aperture to open
>fully - which by the looks of it is wider even than f9. There's no problem
>with a dim ground glass. I probably wouldn't take pictures at that fully
>open aperture (might be a nice effect...) but it certainly helps with
>focussing.
>
>I'm shooting transparency, and as well as looking nice and sharp (I haven't
>done any side by side comparisons, but it looks sharp enough under the loupe
>compared to my other lenses) it's also pretty "snapy"/contrasty in its look.
>
>It does look like it's construction is 2+2


Quite a bit different to the f9.5 then. Mine is uncoated and in a Betax #3 
shutter. The aperture is restricted by the construction of the front and 
rear element holders. The shutter facing part of both lens group barrels 
has a reduced diameter that I bet approximates to f9.5 So there is no 
option of opening it up past the manufacturer's minimum stated f stop.

The idea of limiting the aperture may be due to focus shifts on stopping 
down (?) and increasing lens aberations as the aperture is opened up wider 
than the stated f stop. Both of these effects would have affected the 
reputation of the lens as photographers tried to push the boundaries 
perhaps......

I guess as the f9.5 was a lot more expensive to construct then is would 
make sense to the factory to continue producing the f12.5 and to drop the 
f9.5. Is yours a series III or IIIa?

Anyway, good to know that the f12.5 is a good performer and works well with 
colour. When I finally get around to using the f9.5 will post some of the 
photos.

Cheers,
            Clive