VueScan Question

[mdarnton]

Thanks. I will try that.

[Ted Baker]

I haven't as yet worked out why increasing the Film Base Colors appear to lift the shadow values.

Because Vuescan is attempting to simulate the process of creating an optical print or something along those lines, which is another exposure with an analogue camera. This is not a linear exposure it has a gamma of around 3 or 4, as opposed to the films gamma of around .6 and it own unique Characteristic Curve. (The two combine to give a gamma of around 1.8). How vuescan actually works can only be guessed as there is no documentation on its algorithm, but the film base is used in the calculations.

[IanBarber]

Because Vuescan is attempting to simulate the process of creating an optical print or something along those lines, which is another exposure with an analogue camera. This is not a linear exposure it has a gamma of around 3 or 4, as opposed to the films gamma of around .6 and it own unique Characteristic Curve. (The two combine to give a gamma of around 1.8). How vuescan actually works can only be guessed as there is no documentation on its algorithm, but the film base is used in the calculations.

Thanks ted for the explanation. Would I be right in thinking that using this method is having no adverse affect to the final scan

[IanBarber]

Unless you want to use RAW in Vuescan, this is, in my opinion, a bad habit of Vuescan that isn't easily gotten around. The other end is more problematic, and I have though that I might include a black paper label stuck to my scanner window against the edge of the neg so that VS will be fooled into reading that as the densest area, which will give me some headroom at the other end, too

I am going to re scan this negative later this afternoon using the RAW mode in VueScan and see how it compares to the other method I used.

This only works if you expose enough to make sure there are no clear areas of the neg within your subject area (which is how I expose), and I use this trick to get a scan that's slightly flat at that end of the scale.

During your initial exposure, are you placing your shadow values further up the response curve (Zone 4) to ensure you do not wind up with clear areas in the negative surrounding the subject area.

[Ted Baker]

Thanks ted for the explanation. Would I be right in thinking that using this method is having no adverse affect to the final scan

For B&W only. As long as you don't clip, you use 16bit and you use most of the 16bits when you save the file i.e. it look all right, then there is no real adverse effect IMHO. In that you can correct it with a curve. What I don't like is the inconsistency in comparison to a straight optical process, and the lack of real scientific documentation.

You can use RAW but the steps are more complicated, and depending on the software what really happens varies...

[IanBarber]

During the late 80's early 90's I was very much involved with VB6 and VB.NET but these days, things have moved on so fast. What it needs is someone with some software development skills to sit down with a Photographer and come up with a straight forward piece of software with an intuitive interface and no bells or whistles which will talk to these consumer scanners and deliver a good scan right off the bat without having to fight it all the way.

[Peter De Smidt]

During the late 80's early 90's I was very much involved with VB6 and VB.NET but these days, things have moved on so fast. What it needs is someone with some software development skills to sit down with a Photographer and come up with a straight forward piece of software with an intuitive interface and no bells or whistles which will talk to these consumer scanners and deliver a good scan right off the bat without having to fight it all the way.

Very true, Ian. Even the professional software, e.g. ColorGenius and others, have horrible interfaces. What one wants to do is to easily optimize the capture stage of the scan, as opposed to doing software manipulations on the scanned data, which is what most of the adjustments in scanner software do. This is one advantage of digital camera scanning. At least one has control over the capture.

[Steven Ruttenberg]

When I use Vuescan, I start with either a neutral or no adjustment on the color tab, then put the highlight and dark/black etc all the way to the left and then adjust those if needed while avoiding clipping any data by watching the image data after cropping, can use raw histogram as well. I am just starting to experiment with the exposure settings, etc.