LaserSoft Imaging

I’m scanning 6x6 Black and White negatives.

I get the exposure slider but is the tolerance slider only for colour negatives or is there also a B&W purpose?

Thank you.

Keith Trumbo

Dear Mr Trumbo,

The Tolerance slide is always active.
However with some B&W images you might not see an effect.

Kind regards,
Arne Ketelhohn.

Thanks Arne.

Further, if the Tolerance slider is always active what does it control?

For example, objects shot on a white background the more the slider is used (to the right) the background gets lighter but not necessarily the object.

Is it controlling contrast?

Thank you.

Keith Trumbo

Dear Keith,

It controls how the the expansion are set.
If you have an Ai Studio you can open the NegaFix expert dialog and take a look at the effect in the expansion tab.

Kind Regards,
Arne Ketelhohn.

Good evening,

LSI_Ketelhohn wrote: take a look at the effect in the expansion tab

Doing that I am lost. The “expansion” part of the NegaFix expert dialog is difficult to understand. I would appreciate a description of the various parts of this dialog and their purpose: Histograms, sliders for shadows and highlights, two coloured diagrams with black dot, which can be moved with the mouse.

E.g. if I move the tolerance slider, the black dot in the right hand colour diagram at the bottom (highlights) jumps all over the place, the dot in the left diagram stays put. What does this tell me?

Hermann-Josef Röser

The expansion curves represent the untransformed input histogram of the scan.
The tolerance slider defines how far the shadows and highlights go into the curve.
You can also drag them by hand in the expansion histogram.
The color fields below it is used to compensate color casts by hand.


Kind regards,
Arne Ketelhohn.

Good evening,

unfortunately this does not answer my question: "If I move the tolerance slider, why does the black dot in the lower right panel jump all over the place without any noticeable effect in the preview?"

Furthermore: For me, the tolerance slider only moves the highlights, not the shadows.

And last not least: How are the color fields below to be used to compensate color casts by hand ???

Hermann-Josef Röser

Dear Mr Röser,

The effect of the tolerance slider depends on the image.
In case there are peaks in the histogram the highlight/shadow points may not move.

I do not know what you mean by " black dot in the lower right panel jump all over the place" there is nothing like that happening on my system.
It only jumps back to it's initial point when the auto adjustment reactivates.

Kind regards,
arne Ketelhohn.

Dear Mr. Ketelhohn,

LSI_Ketelhohn wrote:I do not know what you mean by " black dot in the lower right panel jump all over the place"

Well, just that: If I move the tolerance slider from lower to higher values, the highlight markers in the histograms are gradually shifted in from the right towards the rightmost peak. But at the same time, the black dot in the lower righthand coloured diagram jumps -- what seems erratically -- around:

Please note the positions of the black dot.

Still not answered is the question, how does one use these diagrams to remove a colour cast.

Hermann-Josef Röser

Dear Mr Röser,

I can not explain that right now.
It should correspond to the color values represented by the highlight points.
You can then drag them to the intended values. Or pick one by clicking into the intended color.
I personally like it better to adjust the values in the histogram curves

For general cast removal for an emulsion instead of an individual image, the color cast is best removed in the curves (Ausdehnung) tab. Because that can be saved as a custom profile.



Kind regards,
Arne Ketelhohn.

Dear Mr. Ketelhohn,

LSI_Ketelhohn wrote:It should correspond to the color values represented by the highlight points.

Does this mean that there is a bug? Well, there is a bug, certainly, since the tolerance / exposure sliders freeze as soon as one moves the highlight slider ...

LSI_Ketelhohn wrote:color cast is best removed in the curves (Ausdehnung) tab

This is a contradiction! Do you mean "curves" or "expansion" tab?

LSI_Ketelhohn wrote:You can then drag them to the intended values. Or pick one by clicking into the intended color.

What are the "intended values" and what is the "intended colour"?

Looking at the exchange in this thread, I wonder why LSI is not willing to providing a clear and concise description of the expert dialog for NegaFix? It is still not clear, how the lower part of the expansion tab is used to eliminate a colour cast and what the difference to the colour cast removal in the histogram tab is.

Hermann-Josef Röser

Dear Mr Röser,

No it works as intended on my test systems.
So I can not reproduce any bug.

No there is no contradiction. A general color cast should be corrected by adjusting the curves.
The Highlights shadow points are used for adjusting individual images.

The intended values are those you intend to achieve in your images.

Kind regards,
Arne Ketelhohn.

Dear Mr. Ketelhohn,

the screenshot you show above is not what I see on my system (version 8.8.0r5):

The lower part with the slider is missing here. Why is that? I am using HDR.

Hermann-Josef Röser

To see the color field you first must select a location in the image to dislplay.

Kind regards,
Arne Ketelhohn.

Dear Mr. Ketelhohn,

thank you, in the meantime I found out how to get the HSL-diagram.

Having read the SF6 manual I have tried to use the expert mode of NegaFix in SF8 HDR. I could not achieve results as described in the SF6 manual, even worse, following the recipe there the colours are totally ruined. I have collected my findings in a PDF, but unfortunately it cannot be downloaded here. I have exported the first three pages even if they are in German. Perhaps you can tell me what I do wrong.

Hermann-Josef Röser