The negative image has been of interest for some time- for example I have tried digitally blending abstract positive and negative video clips with a variety of blend modes. Recently I stepped back and tried something simpler – combining positive and negative projections of slides with the aim of creating a grey image..
I was interested in the way in which bodies or objects shadowing the projections could then create positive or negative images of their own, but what turned out to be as intriguing was the effect of cancellation – which is imperfect. This kind of faint grey image seeping through seems like a liminal image. An image on the threshold of visibility.
The photograms made using the digital setup replaced the photographic paper with a styrene sheet. Previously the styrene sheet had been used as a material for rear projection.
While the digital photograms looked similar to conventional photograms I was struck by the relationship to projection. In rear projection the image is focused on the screen, or there is a shadow play or equivalent (refractive elements etc). The photogram is therefore a limit case with objects placed in close proximity or in contact with the screen.
In making these photograms – they are very interactive because the image is displayed on a computer in realtime – you become aware of the passage of light in 3D. The screen is a kind of cross section through this light field, which is complex and carries a material trace. You play around with this material.
In rear projection the emphasis is on the focused image on the screen and the defocused space in front of it is an aberration or a means to an end. The logic of the photogram would see this defocused area as just as important, because the photogram is already unfocused.
Another way of putting it would be to see the image existing in 3D in front of the screen with a focused image coinciding with the screen when conventionally focused. Another way of reading a defocused image would be to see it as part of the 3D space, as something in transition towards or away from focus.
So the screen is a kind of threshold in which the 3d light passes into a 2D space. The screen is also architecturally a threshold as well.
Front or rear projection is not just a means to an end. The space of projection is important and can be played with. The photogram or unfocused image is in a kind of liminal state. The screen is a form of threshold.