I think you have mixed up the capture capability (range) and display
capability, 4000ED has d-range of 0 to 4.2, it is enough to capture the
brightness and the darkest range of RVP50.
I don't see why you need to brighten the shadows, brighten the shadows means
you are reducing the display d-range. A normal exposed and extreme high
contrast RVP50 slide may have density from 0.0x to 4.0. If you are playing
with HDR this is another story but 4000ED provide 16x multi-scan, the limit
actually is the film itself not scanner.
Here is a direct scan of RVP50 slide with high contrast scene, from the
histrogram you can see 4000ED has captured almost every details of the
brightest and darkest range. But when displayed on my EIZO monitor it is
reduced to 500:1, that's why people found scanned slide doesn't look as good
as view through lightbox, since you have compressed a 10000:1 image to a
1:500 display.
www.accura.com.hk/temp/RVP-direct.jpg
Here is the adjusted version, which look more close to the original slide
view through lightbox:
www.accura.com.hk/temp/RVP-fit-vision.jpg
Also, I don't see limtation on any negative even T-Max 100 since the d-range
of negative is much more narrow than slide. At the mean time how many
bit/channel doesn't indicate the capture d-range capability of the scanner,
too less bit only create potential bending problem for post editing.
C.H.Ling
----- Original Message -----
From: "Carlos J. Santisteban"
> Hi C.H. and all,
>
> From: "C.H.Ling" <ch_photo@xxxxxxxxxxxxx>
>>Scanning does not reduce dynamic range, your monitor does. If you have a
>>monitor that delivery real 10000:1 contrast ratio you can reproduce the
>>dynamic range of even RVP50, for other slides you may need a little less.
>
> The limitation I find in scanners (at least, the models I have access to)
> is
> shadow detail on slides -- or highlight detail on negatives. When you try
> to
> brighten the shadows and only get noise (even at 16 bit/channel), there's
> nothing the monitor could do.
>
> Of course, the monitor may cause further limitation on DR of displayed
> pictures.
>
> However, I _think_ that using a camera for "scanning" the slides allows to
> get much more shadow detail by using a much longer exposure -- at the
> expense of highlights, of course. This way is possible to make some sort
> of
> HDR pic from the same slide.
--
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