I was experimenting with some stuff called Kodak Linagraph paper today. I really can't find much about it on the web, but it seems rather wacky...
My favourite quick-and-cheerful method for testing new equipment, especially lenses, is to use paper instead of film in the camera. This can be done with any size camera - you need to cut photographic paper to size and perhaps tape it in place inside the camera. Of course this has to be done in the dark, but the advantage of paper is that everything can be done with an orange safelight, so there's no fiddling in the dark.
For large format cameras it's especially easy to load film holders with paper. You may need to be prepared to trim the paper slightly because (believe it or not) 4x5 film is smaller than 4x5 paper (that's the surprising bit) and film holders are designed for film not paper (that's less surprising).
Paper can be exposed like film. It is not sensitive to red light or to much green light much, but in daylight that's not much of a problem. Depending on the paper I expose mine at 2,3,4,6 ISO or higher in daylight. 3ISO is five stops slower than 100ISO. I take my light readings at 100ISO and calculate from there. There's a further advantage that exposures are typically a second or more, so shutters can be dispensed with in favour of the old manual method of using the lens cap as a shutter.
The other advantage is that it's easy to have trays of developer set up in the darkroom, so that (at least if you are shooting your tests in the back garden, which is what I do) each shot can be developed and inspected before the next is taken. Paper is also much cheaper than film.
For Ilford Multigrade paper, which is a little on the slow side but is one of the commonest kinds, I use ISO 3 as a starting point. Others are a bit faster.
After processing, the paper is washed and dried as usual and is scanned on a normal flat bed scanner. If your scanner is reasonable you should be able to get enough detail from even a 35mm negative. No special negative scanner is needed. Of course you will need to invert the tones - you might be able to do this in your scanning software, or any digital processing software will do this. (I use the Gimp.) Less obviously, the image you get will be a mirror image, so a "flip" transform (either left-right or top-bottom) may be helpful, but this is easy in software.
Linagraph direct print paper
I got a quantity of this stuff, which looked like it was worth a try. But it's not designed for normal printing. So on this occasion my paper-negative tests were testing the paper, not the lens. I chose a safe, dependable lens (which was in fact an enlarger lens, but quite good enough for the purpose), fitted it to the camera, loaded some of the paper into the holders and had a go.
A typical negative I got looked like this.
After letting the paper dry and then scanning it and processing it, this was the picture I got.
Pretty good really. There's a nice warm colour, due to my colour-inversion and the fact the paper is slightly cool. The paper appears to be sensitive to green, unlike normal papers, and is quite fast. (I exposed at 16ISO and developed slightly long at 2.5 minutes in PQ universal developer, 1+9.)
Other people may have found some of this paper, so perhaps my very early conclusions on it so far may be useful.
It is fast, at least one and perhaps two stops faster than normal paper. My sample gave a noticeable grey background, which is OK for negatives but not OK for prints. Next time I will try reducing the development time and increasing the exposure, hoping for better whites. Or a different developer might help.
The paper is very delicate when wet and scratches and other marks are very easy to make.
The instructions on the box say to use safelight filter 2, which is a red filter for fast orthochromatic films. Therefore a normal darkroom filter (which is what I used) may not be sufficiently safe. You should certainly experiment.
The pink colour of the emulsion is slightly offputting at first, but it does go when the paper is processed normally.
I thought it might be fun to try the paper in a completely different way, especially as I had no idea what it was specifically designed for.
The sun was bright so I pointed my camera towards it and set the shutter for a long exposure. (In fact, I used 2 seconds at f/11.) And shot.
My first attempt produced (unsurprisingly) a negative that was completely black. Rather than reducing the exposure I decided to reduce the development time, and to my delight, produced a negative in which the sun was perfectly white. After scanning, inverting colours and maximising the tones in the other areas (which are almost uniformly grey, but the scanner could find some slight differences) this is the image.
That's not a negative, but a positive. The sun is quite white on the negative. The other features (for example, a dark doorway to the bottom right) are dark/bright as expected for a positive - everything except the sun.
And it is not hi-fi my any means, and the scratches seem very easy to make on this paper, but this reversal of very bright objects is a lot of fun to do when the materials are right for it. The effect is known, and is usually called "solarisation", but isn't the same as the "Sabbatier effect" (also often called soloarisation, and perhaps something for a future post). Solarisation worked really well with this paper, and much better than conventional paper I tested it against. So this might be an interesting application. More experiments are obviously needed.