The day-for-night never pleased me in colour. I always hated this blue effect that people used in colour for day-for-night, and the blue effect is borrowed from the theatre. It's a stage effect. On the stage, in certain plays and in certainly romantic musicals and things like that, they always used a steel blue, because I've done some theatre lighting I even know the names of the gels that they use in theatre. There's a gel called steel blue which is a faint but distinct blue, and that was always used for the night scenes. So, somehow this idea got transferred to the movies, and the conventional technique, which is in use to this very day, is to add blue, or to photograph it in such a way that blue is already incorporated in the original negative. And those blue night scenes never pleased me very much. Not only that, but it restricts you severely in the countryside where, in black and white, you could do very effective day-for-night work by just using a certain filter, red filter basically, that darkens the sky and the clouds stand out nicely against the dark sky. You can see it in almost any black and white film that has extensive countryside scenes in it, all the westerns, for instance. In black and white, day-for-night is not only a handy and practical working technique, but it's also an aesthetically pleasing technique. And that is not true, both ways it's not true in colour. First of all, it's not very handy to work, because you always have to keep the sky out because there is no way... every way you have of darkening the sky has problems. If you use a neutral density filter, a half... what are they called? I can't think of the names. There's a filter which, no, there's a filter which is half... it doesn't have a hard edge, it's got a soft edge and the bottom is clear. So you have a filter which... it could be 3 x 4-inches and the top half is grey, and then it gradually becomes clear and the bottom half is clear. So you can use that to darken the sky and the bottom half is... you photograph the landscape, and that's fine. But you can't pan with it, you can't tilt with it; very limited. So in most colour day-for-night scenes you see, frequently, the camera is placed artificially high in order to reduce the sky to just a tiny strip at the top of the picture. Now with the system that I developed, for Tom Jones, and that I use to this day, you don't have to do that and it's very effective. But it's completely different. It gives you a look that much more... that resembles natural moonlight much more than this blue thing. Because moonlight is not blue. Moonlight is reflected sunlight, but it only reflects certain lines in the spectrum, so it's... you could say it's monochromatic. Because I knew that it was basically monochromatic, I said, just a minute. The filter that we used to view, it's called a viewing filter, and the filter that we used to view scenes in black and white films, is a monochromatic filter which is sort of... it's a yellowish/green in colour and quite dark, and it helps you to see a scene in black and white. It doesn't turn it into black and white, but it helps you to see it in black and white. Anyway, I said, just a minute, this filter is a monochrome filter, I'll make some experiments. So I made some experiments with shooting through that filter in combination with a pola screen.