Robert,
I have always sot Velvia as rated, except when pushing a stop to 100 when
shooting in low light. The information you provided from Fuji is very
interesting. Thanks for sharing it.
Tom C.
----- Original Message -----
From: "Robert Harris" <[EMAIL PROTECTED]>
To: <[EMAIL PROTECTED]>
Sent: Tuesday, May 08, 2001 6:26 AM
Subject: Re: Velvia questions
> "Gerald F. Cermak" wrote:
>
> > Having never shot Velvia, I don't know to expect. I just finished 4
rolls
> > of Ektachrome 100 while on vacation recently, and am scanning them
tonight.
> > A couple of expected results are there: shadow detail loss, less dynamic
> > range captured, etc.
> >
> > What can I expect from Velvia? I recall discussion of ISO ratings, and
how
> > some people find it better derated slightly - or was that a problem with
> > their light meter? What about pushing and pulling effects?
>
> This is a film you have to test yourself -- experiment with it and play
> with it -- before feeling comfortable that you know when to use it. A
> few comments.
>
> You can expect very vivid colors and very high contrast. Some folks
> consider the results unnatural, and describe colors as Disneyish. In
> general, great for when you want the colors to really pop. May be too
> much if the scene itself very contrasty -- such as high noon shooting in
> direct sunlight. Generally lousy for people photography because of
> really unnatural flesh tones colors.
>
> Pushes a stop well in terms of grain, but contrast picks up even more so
> be very careful, probably best done only in conditions when the light is
> very flat -- heavy overcast rather than when the sun is out.
>
> Speed rating in use is tricky because of the very high contrast of the
> film, and you will have to experiment a bit to decide what you want to
> use, and under what conditions. Even assuming that your meter is
> accurately calibrated, best results may occur at different ratings
> depending on subject, as discussed in the following Fuji document. (This
> was retrieved from a Fuji Compuserve forum library a few years ago,
> can't find it on the web site today).
>
>
> The Speed of Velvia(RVP)
>
> First we would like to make some general comments about the ISO speed
> rating from the factory versus the effective speed when actually
> shooting. Following these comments I will get a little more specific on
> some suggestions for determining the effective film speed for the
> photographer and his/her shooting conditions.
>
> General Comments:
>
> ISO speed is an internationally standardized film speed evaluation
> method and film manufacturers are obligated to use this speed rating on
> their film products.
>
> This method is very different (It only treats B&W and gray and tends to
> evaluate white areas as the most important areas) from how photographers
> check the effective speed of a film.
>
> When films of normal contrast and moderate color saturation are
> evaluated, effective speed and ISO speed rating on the product matches
> nicely. A good example of this would be Fujichrome RDP (ISO 100).
>
> However, Velvia is not a typical reversal film. Because it's high
> contrast with even higher color saturation, there appears to be a
> discrepancy between the procedures. (ISO procedure VS photographers
> normal way of checking effective speed of a film.)
>
> Specifically, Velvia's high contrast results in bigger density
> differences between different exposures. In addition to this, color
> density of mid-tone areas of Velvia is higher than that of gray
> densities. (Remember, the ISO method only deals with grays and
> photographers usually use many different colors for the evaluation of
> film speed.)
>
> Fuji knows that majority of professional photographers set their cameras
> at E.I. 40 when they shoot Velvia. We think this is very reasonable. At
> the same time, Fuji recommends that photographers try E.I. 64 when you
> shoot high key images where whites are very important. Also, we
> recommend trying E.I. 32 or lower when shooting low key images with
> Velvia.
>
> At any rate, Fuji strictly follows ISO procedures to determine ISO
> speeds of all Fuji film products including Velvia. In addition, because
> of our high level quality control, our factory meets the stringent ISO
> 9002 standard for all our film products.
>
> Specifics on Speed Determination
>
> As I mentioned previously, ISO speed determination is a scientific and
> internationally defined procedure and is very different from
> determining the actual effective speed of a film. As a matter of fact,
> the ISO procedure is very complicated and includes standardization of
> many variables. Some of these are: 1. Emulsion-(Emulsion to emulsion
> fluctuation.) 2. Quality of exposure light source-(weather, time of day,
> strobe, etc.) 3. Intensity of the light source- (exposure meter,
> aperture) 4. Exposure time-(shutter) 5. Processing-(Lab to lab and in
> lab variation, control strip variation) 6. Density measurement-(Viewing
> lamp intensity, color temperature, brightness, etc.)
>
> Once again, true ISO measurement utilize gray measurements and no color
> is involved. To do this, you would have to do the following:
>
> 1. Be sure a quality light source is available and that the camera and
> exposure meters are in excellent working order. 2. Shoot a B&W image
> including the brightest whites and deepest shadows. Bracket by 1/3 or
> 1/2 stop increments to have a good range for exposure determination. 3.
> Process the exposed film in a reliable and consistent lab. 4. Evaluate
> the film. Note that the film will not match the scene which was exposed
> on the film. This is due to the fact that one frame may be better for
> mid-tones, while other frames will be better for whites, blacks,
> shadows, etc. As you can see, a higher speed might be selected for
> whites and a slower speed for blacks. Your ISO speed should be for
> whites.
>
> * Try the same procedure on color images and you will yield different
> results.
>
> Generally it is not a good idea to check the ISO speed of a film. A
> better method is to establish your exposure index E.I. with your light
> source, your exposure meter, your lab and your viewing conditions. When
> establishing your exposure index, don't forget to try using a one third
> stop faster speed for high key images and one half stop slower speed for
> low key images.
>
> Many photographers rate Velvia as an E.I. 40 film because the color
> density of Velvia is a little higher than the gray density in the
> mid-tone area. However, this does not mean that the ISO speed of Velvia
> is 40.
-
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