Re: filmscanners: VueScan Histogram was VueScan 7.3.2

["Bob Armstrong" <bob.911@btinternet.com>]

michael wrote:

> Bob writes ...

> > And, how can you know where to set the B/W points if
> > you don't use a histogram ;)
> 
>I have 2 problems with that question: 

>(1) I suppose I don't know exactly what you are trying to do?

Trying to find out how VS users get the most out of a scan when using VS.  
(Which begs the question of what 'most' means.  You say VS can put *all* the 
RGB into a scan and make it stretch from one end of the histogram to the other, 
as well
as exclude a certain percentage (which might be considered noise, or specular 
highlights without detail).  I would agree that generally this would be a 
suitable definition for getting the most out of a scan.)   

>(2) a histogram is a visual tool, but it would be extremely difficult to 
>present a truely useful histogram.  A case on point is Photoshop's 
>histogram ... for accurately using it, do you pay attention to the 
>visual or do you pay attention to the numbers?

Both.    
 
>(1)  It has always been the philosohy for Vuescan ... "if there is a 
>better tool in the subsequent RGB editing software, leave Vs to the 
>basics."

I've heard that said and don't disagree with it.   

>(2)  What would you have the histogram show?  The preview's pixels
>or absolutely ^all^ of the pixels? Numeric feedback for 8bit RGB or 
>16bit? ... each individual RGB channel or some calculated "luminosity" 
>value?  Which luminosity value? ... 'L' of Lab? ... 'B' of HSB?

A histogram of the scan at the bit level the scanner can produce.  Preferably 
luminosity, if not RGB would do if they were displayed together.

>I don't have a problem with Ed adding a histogram, but I cannot 
>imagine it otherwise being only a visual presentation, and not 
>practically that useful. But let's all decide first on which histogram we 
>want before we ask Ed to change it again ... and again.

VuePrint has a histogram with some numbers but not the numeric detail of 
Photoshop's histogram.  Why would a histogram in VS be 'not practically that 
useful'?  Last I heard indicated Ed didn't wants to add a histogram to VS so we 
may not get a chance to ask him to change it again and again...

Hope this helps you understand what I am trying to do.  Do you change B/W 
points in VS?  If so why and how do you decide what they should be?  

Bob
still very confused about scanning