Re: Home made Lenses ( soft focus )

On 04-Mar-2005 Tom Ferguson wrote:
>
> I've never seen a three element color corrected and coated Veritar! My
> 10 inch is two single uncoated elements with nothing but space and an
> alphax shutter between them.

> On Friday, March 4, 2005, at 11:33 AM, John Cremati wrote:

>> Tom,
>> I believe the commercial Soft Focus Lenses go far beyond the
>> mounting two or 3 diopter lenses in a barrel.... As a example the lens
>> which
>> I had purchased is a color corrected Wollensak Veritar. It is a 3
>> element design engineered to reduce chromatic aberration , so it is
>> suitable for color. It achieves its softness by controlled Spherical
>> aberration...

The resolution is that the Veritar consists of 3 elements in 2 groups. This
is what is shown in the cross-section view in an original Wollensak brochure
that I have. The number of elements is confirmed by shinning a flashlight at
the two groups: the front shows two reflections, while the rear shows three.
There is more to the design of the Veritar than placing two single-element
lenses on each side of the aperture. AFAIK, Wollensak only used this design
for the Veritar. You can check yours with a flashlight -- unscrew the groups
from the shutter and count the reflections.

--Michael
Received on Sun Mar 6 22:13:13 2005