I decided it would be interesting to do a false colour image of Venus, with a convention I made up, at least I think so. It seemed to me that since Venus really only shows a lot of structure at the Blue, Violet, UV end of the spectrum, I could simply “spectrum shift” these into the visible spectrum, mapping Blue to Red, Violet to Green and UV to Blue. In many ways this makes more sense to me than the IR(G)UV convention.

In Revision B I show the 3 spectra and how I shift them to the visible spectrum. The RGB spectra for my Chroma filters show where the RGB spectrum sits relative to the Blue, Violet and UV. Strictly speaking I end up cutting off some of the Violet Wratten #47 UV spectrum, because I use it in series with a Luminance filter. It leaks IR quite badly, so this is an expedient to stop the IR fogging the image. I would like to get an IR cut filter than allows all the UV through but have not been able to source one as yet. Apparently the Schott B39 or B40 would do the job, but I have not been able to find a source for 1.25" mounted filters that I could put in series with my Violet Wratten #37. Does anyone know where I could source such a filter?

Anyway here is the result. The amount of structure I resolved in Blue is the best I’ve ever achieved and very much mirrors that in Violet and UV, but is subtle different. To my way of thinking, why should not the Blue, Violet and UV be as different as Red is from Green is from Blue? I imagine Venusians going into orbit and this being how they would see their planet. Having said that I am not sure whether the Blue-violet-Ultraviolet end of the spectrum would be of any relevance on the surface of Venus.

 The false colour image has a certain beauty, don't you think?  If nothing else it allows us to see in visible light the complexities of a wider range of spectra than is possible to see in a single monochrome image with one of the filters.