Glad to help out! Removal of the crossover mask is probably the most vexing part of working with color negative processing because it varies by the type of film, the particular way a film was processed, and the age of the film as well. I remember from working in the photofinishing lab … it was no better then, a skilled print machine operator simply looked at the film and knew how much to tweak the reference settings based on the experience of having down a few thousand frames.
In this album on flickr - https://www.flickr.com/gp/gdgphoto/QJ437u - I show a simplistic capture setup with a random B&W negative and then another capture of a random color negative. I used the White Balance dropper on the film rebate between frames to neutralize the crossover mask and then tweaked it further in the finish rendered image. This particular film had a relatively light crossover mask; other films have much deeper hue'ed crossover masks. I don't know that a reference gray/color target is going to give much better information than just using the rebate of the film unless it was made at the same time as the original images on that same film. It's always just a rough starting point for my image processing. There's as much feel and art to this as there is science IMO, because we all tend to perceive color slightly differently and what is too cool for one person is often just right for another. Unless you're working with specific colormetric type materials and needs… forensic and science data, for instance. For that example photo, I found that the crossover mask removal was reasonable and technically about right, but that the resultant image felt a little dull and cool, so I then warmed it up with a shift in the color temperature and hue controls, poked at the contrast a touch. G > On Apr 19, 2020, at 12:18 PM, Bob Pdml <[email protected]> wrote: > > Thanks Godfrey, that’s very helpful and I’ll experiment with your methods. > I’ve already discovered dragging the tone curves; the orange mask is a bit > problematic at the moment. > > It occurs to me that if I were to shoot a slide each of a colour target and a > grey card under daylight (my lightbox is 5000K), and include them on each > colour index print, it might help in some way. Or I might just be > overcomplicating something that only needs to be good enough, not perfect. > [… snip …] -- PDML Pentax-Discuss Mail List [email protected] http://pdml.net/mailman/listinfo/pdml_pdml.net to UNSUBSCRIBE from the PDML, please visit the link directly above and follow the directions.
