Scanning: Silverfast question - histogram and dynamic range et al

Started 9 months ago | Discussions thread
SilverFast-LSI
SilverFast-LSI New Member • Posts: 6
Re: Scanning: Silverfast question - histogram and dynamic range et al
1

Overrank wrote:

So if I scan a slide and then within Silverfast move the black point to the lower edge of the histogram and the white point to the upper edge of the histogram, and then save as a 48bit TIFF would I get the data binned on a finer mesh than if I didn’t adjust the black / white points first ? Like the OP I’m using Silverfast 9, although with a Reflecta 10T

Hi,

I'm not sure if I understand the question correctly but if a scan is saved as 48-bit it ...

- doesn't make a difference if the white- and black point adjustments are done in the scanning phase, or later in HDR-Studio or any other post processing step.

- does make a difference whether the saved image/scan will be printed afterwards, because the pixel values will be modified.

I think one important distinction is the SilverFast histogram dialog ( or widget) will represent the input data from the scanner (holding down the ALT-key will display the output histogram). When setting the black and white point further into the available data, we have to spread open (or "aufspreizen" as we say in german LOL) the available histogram, which will result in more levels of gray in the final/output/exported image (than before) but we can only add them by interpolation, not to be confused with interpolation of pixels to upscale an image with a given amount of pixels.

The "mesh density" will be defined by the bitdepth, so some 65k+ per channel. Hope this helps - Jan

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