I see Ali Express now sells achromatic doublets for amateur telescope makers, I was wondering if anyone has any experience with these? They come with either a blue or a green coating for astronomy, which would be the best for shooting X-ray film, or should it be polished off before use?

Thinking of several uses, including fitting one to the rear of a Shanel 5B shutter for use as a soft-focus lens.

80mm Doublet Aperture Refractive Glass Achromatic Objective Lens