On Tue, Apr 28, 2009 at 9:14 AM, Ken Norton <ken@xxxxxxxxxxx> wrote:
>>
>> You mentioned that there is depth to film that you dont see in digi, arent
>> you loosing that during the A/D conversion?
>>
>
>
> No. It has to do with the tonal bias the film assigns to the captured light.
>
> For example, in a bright sunny day in wintertime, you'll see the snow in the
> shadows turn blue in digital capture. Some films will react differently to
> this specific shade of blue and either turn the shadows magenta, green, gray
> or blue--all while leaving the sunlit portions neutral.
>
> Another example, would be in a mixed flash and tungsten lighting. As you
> have the WB set for flash (daylight or approximately 5300 Kelvin) the
> tungsten lighting in the background will turn quite orange. However, with
> some films, the tungsten lighting will warm, but won't turn nuclear.
>
> What does that have to do with poor lighting? Print films are more
> forgiving than digital because the exposure response curve is not linear. As
> you underexpose the film by one stop, it only decreases by .8 stop. As you
> underexpose the film by two stops, it only decreases 1.5 stops. As you
> underexpose the film by three stops, it only decreases 2 stops. The farther
> you get from the nominal exposure (mid-tone, properly exposed), the less
> change it has. Only in the middle exposures (+/- 1 stop from mid-tone) is
> the response anywhere close to linear. Velvia is an example of a film that
> stretches the mid-tones and instead of compressing the low-values, it just
> drops them off into blackness.
>
> So, in my concert shoot, using identical exposures and ISOs, the digital
> image has more blown highlights from the follow-spots and nearly no
> background. The house lights were set extremely low (safety lighting, only).
> The digital images have black backgrounds, the film images actually have
> substantial color and background details. The highlights in the film images
> are still blowing out, but the transision is smoother in an organic way
> without the nasty color shifts and harshness.
>
> Scanning the film makes no difference, because the film has captured the
> extremely wide light-levels and compressed them into a range the scanner is
> able to use. The mid-tones still have a proper contrast, but the highlights
> and shadows are pulled in.
Is this anything other than an explanation of how film, print film
that is, has greater dynamic range than digital capture? I was
thinking there was something more rhapsodic in your tone at the time.
Joel W.
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