Seeking True Solarizing Film

[patrick_holderness]

<p>Hello all, I was wondering if anyone could tell me of a commercially available film that is capable of true solarization, e.g massive overexposure leading to an actual decrease in density on the negative. I am interested in achieving this at the moment of exposure, and not pseudo solarisation during developing. I understand that this feature has been eliminated from most modern films as its undesirable to most users, but can anyone point me towards a film thats still capable of this?<br>

Thanks,<br>

Patrick</p><div></div>

[Alan Marcus]

<p>You are on the right track! Solarization is a partial reversal seen when films are grossly over-exposed. You can find technical details about a film at the manufacturer's website. Look at the characteristic curve, an "S" shaped graph of how the film blackens with increasing exposure. This curve is divided into three regions. The beginning is called the toe, followed by a straight line and then a shoulder. The toe shows us that the film is sluggish as to blackening at low exposure levels. The straight line shows us that the film's response becomes linear. Increasing exposure yields proportional blackening. The shoulder region tells us that the film is not responding linearly as it approaches maximum blackening. Some films will display a fourth region. The graph, after reaching density maximum (after the shoulder) begins to descend. This tells us that continued exposure will yield a reduction in density. This effect is small with modern films. This fourth region is called the region of Solarization. This is the partial reversal you are inquiring about. It is more commonly observed in X-ray films as opposed to camera films. I suggest you try some. You could borrow a view camera that accepts 4x5 inch sheet film and cut some X-ray film to fit. Treat this as a neat project.</p>

<p>Another similar effect, often mislabeled Solarization is the Sabattier Effect. This is a partial reversal of film, or more commonly, photo paper. This effect is induced in the darkroom. We give the film or paper a lower than normal exposure followed by a shorter than normal developing time. The film or paper is then intentionally fogged (exposed to a diffused light). The film or paper is again placed in the developer solution. The result is a partial reversal that resembles Solarization.</p>

<p>Let me add that any negative will appear as a positive image if placed on a highly reflective black background. The tintype, a popular photo method was an emulsion coated on metal painted with Japan Black lacquer. The material was underexposed by today's standards. After developing and fixing, a positive image is seen, however, the image is reversed left to right.</p>

<p>Good luck, more gobbledygook from Alan Marcus </p>

[john_a5]

<p>A little searching and I finally found this guy who does this sort of thing. As I remembered, he currently uses silver printing paper, but says he did some imagery with film. You might write him. I haven't seen film reverse in many years although I did get some black suns with my early digital camera.</p>

<p>http://www.chrismccaw.com/SUNBURN/SUNBURN.html</p>

[profhlynnjones]

<p>Kodak made such a film 15 or 20 years ago called "direct reversal" or something like that, from your enlarger you could create a negative from a negative. In my 6 decades of experience I have only seen this by accident. We would occasionally see it with low speed color negative films in dusk time available light exposures when auto head lights would be very over exposed and parts of the photo would be reversed. I doubt if that helps but at least one other person knows what it is.<br>

Lynn</p>