10998061

That is absolutely right, but I wonder whether he had found the image from the same source (it has been copied many times across sites). This link also has the transmission data in tabular form (as per your suggestion). But as you rightly point out, if he has not checked back since August, it is all pretty hypothetical!

Hi Completely new here (ie photo.net), and it is not clear whether this thread still interests anybody .... Many years ago I was a spectroscopist and we used to model spectra as a linear combination of gaussian curves. A play with the Ilford data (for which my thanks to Ilford) shows that all those curves can be modelled pretty well as being the sum of 4 Gaussians ( at 432,512,530 and 568nM, subject to refinement). In differing proportions obviously! I second approach is to use the data on the Olympus site, eg Photomicrography - Color Compensating Filters - Magenta | Solutions Olympus pour les sciences de la vie Which provides the transmittance data at 10nM intervals for a variety of enlarger filter settings. Interpolating/extrapolating to other settings should not be difficult. Hope that helps Scott, both approaches are easier and more accurate than tracing the curves!