Setting up to use PHOTON optimally

PHOTON is created using pictures which have been finely-tuned for graphic reproduction in print on accurately linearized systems. Monitors are calibrated using a SuperMatch probe and will shortly be set up using LightSource Inc's Colortron device - look out for our review of the functions of this hand-held spectrophotometer shortly. Our Varityper imagesetter and various laser printers are calibrated using a VIPtronic 130 densitometer. Viewing conditions are controlled the best way the Regency architect of Maxwell Place knew how - by closing 180-year-old wooden shutters!

Our magazine quality is controlled using a DW Viewpacks Ltd Viewbooth, a table-top 5000K viewing booth with a 10 x 8 tranny area and a shielded scoop for A3 proofs. We use a Kodak ColorEase PS printer for visual checking and Du Pont Cromalins from the occasional page, usually only one per issue.

The end result is that after three years of work, we have found a screen gamma of 1.4 most correctly represents the final printed page, whether in Photoshop, PageMaker or XPress. A gamma of 1.8 may look stronger and richer, but can lead to scratchy shadows and weak solids, or overall desaturation. However, users of uncalibrated imagesetters, or whose printers have very high dot gain, will find 1.8 a better representation - so most commercial printers with Linotronic setters stick to 1.8. Our imagesetter is very linear with the TransCal HiLine screening and Du Pont film we use. Previously we had a Linotronic with Agfa or Fuji film, and it was entirely different, calling for considerable over-correction to open up the shadows.

Our images are either very small JPEG files at 50% quality, sometimes only using 2-3Kb to show a fairly large picture, or interlaced GIFs. The JPEGs are preferred because they have better color and less obvious dithering, but some browsers have problems reading them. We use NetScape and Mosaic, and on the Mac either of these programs should view PHOTON correctly.

So, for the best set-up, make sure your browser can read JPEGs (all browsers will handle GIFs), and set up your monitor for clean viewing at gamma 1.4. If in doubt, the test strip below will help you.

It is a 256-greyscale GIF. The left-hand end is 100% black on the outside running to 0% at the right. The central strip is 95% black on the left half, 5% grey on the right. The two reference tags show the points where the center strips and the outside grads should match. You should see the 5% grey clearly compared to the pure white, and the 95% grey should be equally well picked out from black. In fact, it will look as if the 95% and 5% strips have graded ends, because of their contrast with the graded strips.

If you can't see the differences at both ends, adjust your monitor brightness and contrast, or use a gamma control utility, until you do. The exact setting will depend on your monitor and you may prefer gamma 1.5, 1.6 or 1.7. In low room light, our Hitachi monitor is best at 1.65 (unadjusted, native contrast) but with some daylight present, 1.4 is essential.

The only other techstuff about PHOTON is that we used the Hypercard 'Simple HTML Editor' for most authoring, keeping its window open next to NetScape and previewing changes by reloading. Our files are all created at Icon's offices in Kelso, and the net server TweedNet is a fifteen-minute drive away, straight up the Tweed past Floors Castle and Smailholm Tower, into sight of the Eildon Hills, and thence to the Tweed Horizons Centre. If you're really curious about this whole place, and why we're here, and what was here before us, you can read some mythstuff but it isn't for photographers or 'terminal' cases. It's for poets and synapse astronauts. Mainstream readers can go back to the real world.