RE: Just to be sure I understand...

["Willem-Jan Markerink" <w.j.markerink@xxxxx>]

On 10 Sep 99 at 8:07, Barry B. Bean wrote:

> On Thu, 9 Sep 1999 21:00:02 -0400, George L Smyth wrote:
> 
> >I don't think you'll find much difference between a #25 and #29 filter.  When I tested, I
> >found a very small difference, but certainly not enough to compensate for the speed
> >difference
> 
> Hmm - according to Tiffen, the 25 is worth 3 stops, but the 29 is
> worth 4 1/3 stops.

Unless they mention a specific film for this value, it doesn't mean
much....the closer you get to the end of the sensitivity curve
(steeper incline) of a given film, the more effect a slightly darker
filter will have. In extremum you could push it just over the sensitivity 
of the film, and end up with an EI approaching zero, ie an infinite 
amount of stops difference.

--                 
Bye,

Willem-Jan Markerink


      The desire to understand 
is sometimes far less intelligent than
     the inability to understand


<w.j.markerink@xxxxx>
[note: 'a-one' & 'en-el'!]
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