Someday I may write a general introduction to VueScan, but for today I am assuming that you have the basics down. I highly recommend the VueScan Bible as a starting point.
For slide film (positive) profiling you:
- Obtain color target slide(s) in your film(s) of choice
- Scan the color target slide using your scanner (no need to save)
- Use the Profile Scanner function (it will require the data file that came with the target) and save the profile with a descriptive name (in case you have multiple scanners and/or films)
- Use the resulting profile in the "Color | Scanner ICC profile" field to base the color of future scans of this film
This results in slide scans to be very true to the original as viewed on a light box. Of course, if the color cast in the slide is off you will need to correct it later (Lightroom, Photoshop, etc.).
For color print film (negative) profiling you:
- Obtain color target in your slide film of choice or a printed target
- Take a photograph of said target using your film camera & negative film of choice under normal lighting. Use even or diffused mid-day sunlight or flash.
- Process and scan the negative film frame with the color target (no need to save)
- Use the Profile Film function in a similar fashion as above, feeding it the data file for the color target you took the photograph of
- Use the resulting profile in the "Color | Film ICC profile" field to base the color of future scans of this film
This results in negative scans to be very neutral and consistent in color. Again, if the color cast was off in the shot to begin with it will still need some correction.
I used my Nikon F6, a macro lens, and a slide copying adapter to shoot a Fuji Provia 100F slide target. You can probably make use of any camera-lens with decent close focus ability to shoot a printed color target.
Using a neutral target like Provia for profiling Kodak Portra 400 shots produces very natural results. I tried a Velvia target for fun (which has very saturated colors) and the resulting profile was wonky and "not Portra like".
This process is a bit of a hassle to setup, but once you have the profiles in place you can save a lot of time by reducing your "normalizing" color correction work.