[LargeFormat] Wolley Ex W 6.25" f12.5 series III 8x10

[Clive Warren]

At 3:00 pm -0700 14/8/02, Richard Knoppow wrote:
>At 01:19 PM 08/14/2002 -0700, you wrote:
>>I finally got around to fixing this lens I got in a box lot of other
>>neat stuff.
>>
>>I've noticed that the iris is limited to f12.5 but the glass is much
>>larger than that.
>>
>>I was wondering what part of life as I or the lens knows it would come
>>to an end if I removed the stop and allowed the iris to open up to it's
>>full potiential?
>>
>>While I understand anything less that 12.5 will not give desireable
>>sharpness,
>>
>>but it might be a whole lot easier to focus........unless there's a
>>focus shift when you stop down on this lens.
>>
>>Any body have any experience with this one?
>>
>>
>>Les
>>
>   I am not sure what design this lens is but believe its a Series IV Protar.
>   The oversize elements are to prevent mechanical vignetting. The lens
>opens to f/12.5 for focusing and composition. It should be stopped down to
>f/36 for use. The maximum coverage is at f/45.
>   The Wide Angle Protars are part of the family of lenses designed by Paul
>Rudolph, of Zeiss, and considered to be the first anastigmats. They are
>four elements in two cemented groups. The front is made of "old" glass, the
>rear of "new" or Jena glass. Wollensak may well have modified the design.
>   You can tell something about the construction of the lens by shining a
>flashlight into it and counting reflections. Glass-air refelctions are
>bright, cemented surfaces are very dim. Even in single coated lenses the
>coated surfaces will have much brighter reflections than the cemented ones.
>I have a couple of multicoated lenses and its still possible to
>differentiate the surfaces. If I am right each cell will have two bright
>and one dim reflection.
>   I think Wollensak may also have made an f/12.5 version of a lens which is
>more commonly f/9.5. Essentially a four element double-gauss type but with
>all four elements compounded. The reflections from this type will show four
>bright and two dim reflections per cell.
>   The same thing about stop applies to this type, wide open is for
>composing, the lens is meant to work at around f/22 - f/36 mimimum.
>----
>Richard Knoppow

Hello Les and Richard,

Would normally snip posts but all of the above is relevant!

I have the Wolly Velo Extreme WA Series III 6.25" f9.5 which is 
uncoated and in a Betax #3 shutter. Have only recently dug it out of 
a draw and CLA'd the shutter.

This lens is also iris restricted with larger glass. As Richard 
suggests this is probably to avoid mechanical vignetting. You could 
open it up to make focusing easier by removing the iris plate - the 
world would probably keep spinning ;-)

Les, the f9.5 is probably easier to focus than the f12.5 but both are 
searingly bright compared to the Protars that you like using....

As for numbers of elements, the f9.5 has four in each cell according 
to my count by reflected light. The f9.5 was in production later than 
the f12.5 although both probably continued in production with one 
maybe less expensive than the other? Later versions were coated. 
Seems as though the lenses are possibly of different construction - 
how many elements in your f12.5?

Here is something from a Wollensak catalog (No 44) talking about the f12.5.

"The genuine merits and unlimited possibilities of the Series IIIa 
lens have gained for it a host of enthusiastic friends"

The angle of view is stated at 90 degrees with 100 degrees when stopped down.

"..... (the lens) gives good definition at full aperture; wiry 
sharpness when stopped down"

So to avoid all that wiry sharpness you can shoot with it wide open ;-)

Cheers,
        Clive