REFRACTOGRAPHY – NO LENS LIGHTPAINTING
In this photographic technique, an object that can refract light is placed in front of the camera and illuminated with a thin, bright beam of light. The camera’s sensor then records this light refraction. In this case, the camera is used without a lens. Depending on the material used, the most diverse shapes result. By moving the object in front of the camera, the shape, size and brightness change.
In order to get a respectable result on the sensor, a little patience and sure instinct is necessary. With the slightest movement, the appearance of the light figures often changes very clearly. But for rainy autumn days, I think this is just the right thing.
WHAT I NEED FOR THAT?
First of all, a camera with an interchangeable lens system. The lens is removed for this type of photography. The camera must be able to release the shutter without a lens. With some cameras, the shutter release is blocked when no lens is attached. I use either my Nikon D750 or D300s for these pictures. The camera should have a stable stand, so a tripod would be a good idea. Next you need a torch. For the pictures in this post I used a torch with about 800 lumens. Then you need a small piece of cardboard the size of the lamp head and some gaffa tape. And then you need an object made of glass or plastic that can refract light. Wine or champagne glasses are good for first attempts.
I used broken glass for most of the images in this post. Because of the many broken edges, there are more possibilities than with wine glasses or similar. In addition, a “rainbow” sometimes becomes visible with the broken glass. I have not been able to do this with intact glass. In my experience, the “sharpness” of the image depends on the quality of the glass. Refractographs of good, “clean” glass usually look better than those of cheap pressed glass, if anything can be seen with it at all. I haven’t tried plastic yet, but theoretically it should work as well. If you want to bring some colour into the picture, you need a few small pieces of colour filter foil.
HOW IS IT DONE?
Set the camera to your working height with the tripod and align it reasonably straight. In front of the camera, you attach your glass object, preferably so that it can be moved easily. Alternatively, you can simply lay everything on the table. Poke a small hole in the small piece of cardboard, about 2 to 3mm in size. Use the gaffa tape to attach the cardboard to the lamp head. Attach the lamp exactly parallel to the camera, so that the light shines past the front of the camera and hits the glass object exactly. The distance between the lamp and the glass should be between 2 and 5 metres, depending on the brightness of the lamp.
In no case should the whole glass shine brightly, because we only want to record the refraction traces of the light and not the actual object. You should not get the idea of using a laser. The light is much too bright and there is a risk of damaging the sensor of your camera. Now switch on the camera’s Live View and move the object slowly and in small steps in front of the camera. When you like the shape, take the picture. The ISO value should be between 100 and 200. With the 800 lumen lamp at a distance of 3 metres, the exposure time is about 1 second. However, only test shots can help here. As long as you do not move the glass or the lamp, the image remains the same. The time varies quite a bit because the properties of the different types of glass paint different bright patterns on the sensor.
To get some colour into the picture, you cut narrow strips of colour filter foil. You then hold these either between the light and the glass or between the glass and the camera. This also requires a bit of intuition, at the latest if you want to use several colours in one picture.
REFRACTOGRAPHY IN COMBINATION WITH OTEHR LIGHTPAINTING ELEMENTS
Of course, you can create impressive images with refractography alone. But as you can see in the example picture, it can also be combined well with light painting. Here I first shot the refractography as described above, switched off the torch and attached the lens to the camera, in this case a Helios 44-2. Then I took the camera off the tripod and shot the bokeh freehand. For this I used a bundle of black glass fibres and a torch in flash mode. Of course, combinations with other light painting elements are also conceivable, there are almost no limits to your imagination. However, you should take care to avoid even the slightest movement of the tripod or the glass so that you can reproduce the image if necessary.
The difficulty here lies in the planning. You cannot predict with certainty what the refractography will look like and then have to improvise for the light painting when you see what form the refractography will take. Only the colours can be determined in advance.
At this point I would like to thank Rob Turney for his pioneering work. Without his pictures and his tutorials I would probably never have had the idea to try refractography.
In this sense I wish you good light all the time.