At 22:23 4/7/99 , Giles wrote:
>
>This topic brings to the fore something I have wondered about.
>
>What does a soft focus lens do specifically that a a diffusion filter or
>vaseline on
>a skylight won't. Do they have the same resolution and contrast as a
>conventional
>lens?
>
>Giles
Hi,
New to this list, but not to OM equipment (almost 20 years) or photography
(longer . . . but won't say how long or you'll think I'm an old man ;-) ).
If a URL wraps, make sure you copy in the whole thing!
B&H Photo-Video's web site has some discussion of the differences under
both the B+W, Heliopan, and Hoya descriptions: The following URL's will
vector you to each one:
http://www.bhphotovideo.com/photo/filters/glass/bw/sfx.html
http://www.bhphotovideo.com/photo/filters/glass/heliopan/sfx.html#soft
http://www.bhphotovideo.com/photo/filters/glass/hoya/fog.html
At Schneider-Kreuznach's web site (they make B+W filters)
http://www.schneideroptics.com/filters/list/10/soft2.html
If you sprechen Deutsch, you can read descriptions of different types on
Heliopan's web site (hey, the company is German . . . so why should it be
in English?)
http://www.heliopan.de/prod12.html
http://www.heliopan.de/prod13.html
It seems as if the difference is in how the surface is "roughened" to
achieve the softening or fogging. The "vaseline on a UV" trick is very
good. Another is borrowing (stealing?) your wife's nylon stockings (or
your own if you're female; I "won't go there" for other possible
combinations of who the hose belongs to) and stretching it over a UV
filter. Some of the newer stuff out there has slightly different effects
depending on whether or not you want:
1. slight halo
2. enhancement or reduction by changing the aperture
3. retention of contrast and/or resolution
The typical methods seem to be:
1. tiny concentric rings
2. tiny round bumps
3. tiny prisms (sharp bumps)
4. tiny random shaped bumps (like some shower doors and similar to the
vaseline trick)
5. tiny grid lines (similar to the nylon stocking but finer)
Hope this helps you out. I bought a Hoya 20 years ago before all this
fancy stuff got created. I believe it is the tiny random bumps type.
-- John
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