Vuescan black and white points

I am wondering if there is some way to turn off the initial automatic selection of black and white points in Vuescan. They are accurately chosen but that's not what I want. In particular, I want to assign both black and white to numbers more outside the histogram range, for instance getting 10 for the darkest reading of black and 245 for white, making a low contrast scan with some grey space at either end. Vuescan is happy to let me move the black and white points more into the histogram, dropping values at the ends, but won't permit the reverse, setting black to -10 or white to 265. In Photoshop levels this would be the equivalent of moving the points inward on the lower scale in the levels setting rather than the upper scale.

 

Ideally, I would want to do this with the minimum of fuss, while retaining the possibility to change the other available settings. I don't want to do something like export a raw file and do all of this in some other program--that sort of defeats the point of having Vuescan at all.

I think setting wider black and white points is, err, a bit pointless. To the best of my knowledge, Vuescan chooses the highest and lowest negative densities within the picture frame as its B&W references. Setting the points at non-existent higher and lower densities would simply result in artificial greying of highlights and shadows, while not revealing any more detail.

 

The same could be done with the curves tool, by lowering the top of the curve and raising the bottom.

 

To reveal more actual detail in highlights and shadows, the curves tool gradient needs to be made steeper in the highlight and shadow areas, not shallower.

 

Maybe adjusting your developing time or exposure would be a better option? Scans from over-developed negatives are never very satisfactory.

I gather no one has a way to do this, then.

I use Epson Scan, and the limits are 0 and 255, respectively.

I scan flat using Epson Scan. How do you adjust levels in Lightroom? In Elements, you have Levels and it's rather easy.

I scan flat using Epson Scan. How do you adjust levels in Lightroom? .

More importantly WHY would you do so when you can in the scanning software with less data loss and time lose assuming you can pull curves there (and if not, you need better scanning software!).

I use Epson Scan, and the limits are 0 and 255, respectively.

That implies it is the limit set not what can be scanned. IOW, one can clip to either while there is actual data on either side prior to the clipping.