EPIcentre Computer Monitor Lineup Charts WHAT YOU SEE - IS IT REALLY WHAT YOU GET? Although we spend a great deal of time configuring our computers, it's a sad fact that most computer monitors are not adjusted to view all the detail in the images displayed upon them. This is hardly surprising when computer manuals ignore this important area, leaving users to set Brightness and Contrast using nothing more than guesstimation. Correct monitor adjustment is a neglected area of computer setup. In the world of wordprocessing, spreadsheets and colourful graphics all that matters is that images are punchy and colourful. But in the world of digital imaging, with photographic quality images, a correctly set up monitor is essential for serious work. People get frightened by colour WYSIWYG - what you see is what (you hope) you get - having been led to believe that the only way to get it right is to throw money at the "problem". Fortunately, that's not so. IT'S FREE! The good news is, you already have most of the solution, free. Your eyes and common sense are all that is needed, together with some thought and a logical approach. This section contains everything required to carry out a basic set-up of your computer's colour monitor and printer. The techniques outlined here will get you 95% of the way to lining-up your system to perfection. Gnawing away at the other 5% could cost you a lot of money. And you have to face the fact that you can never achieve 100% fidelity. HOW DO YOU VIEW? The first thing to pay attention to is your working environment - your computer's Desktop Pattern and the ambient light in which you work. SETTING THE DESKTOPS If you use an Apple Macintosh computer you have a utility called "Desktop Pictures" in your "Control Panels" folder, which is in turn inside the "System Folder" on your hard disk. Open this Control Panel and select the 1-bit Gray desktop pattern now (it's pattern 47 in the list). Alternatively, select Silver accent (pattern 10 in the list) which is also neutral. Click "Set Desktop Pattern". Close the Control Panel. On no account should you select a coloured desktop pattern - they are there only to brighten the mundane lives of unfortunate people who have to spend their entire lives looking at spreadsheets. In digital imaging, a brightly coloured desktop is a sure sign of someone who doesn't understand what he or she is doing. You have been warned! If you choose to ignore this advice and select a coloured desktop, your eyes will be assaulted and desensitised by the colour you choose. All images you judge against it will appear to be lacking in its colour. For example, if you choose the magenta desktop (and who in their right mind would?) all images you view against it will appear green, forcing you to add magenta to make them look right. But when someone views your images against a grey background, they will have a magenta bias. If you really want something other than a flat grey desktop, at least use a neutral one. The background we use at this Website is textured but - importantly when viewing images - the greys in it are neutral. So let's get it right from the start. A grey desktop is a clear indication of a knowledgable digital imager. THE RIGHT FURNITURE The same also holds for the desktop on which your workstation sits. Buy a neutral grey desk or table if you can. Make sure it's grey by taking along a Kodak Grey Card and laying it on the desktop in the showroom. (Kodak Grey Cards are available at all good photographic stores.) The desk you buy doesn't have to be the same tone (18%) but it should be neutral grey - the card will help you spot whether the desk's grey has some colour in it. I have nice wooden tables from Ikea. They're strong and not as expensive as "bespoke" computer furniture. But the natural wood is not what I want to bias my eyes with, so I use grey plastic desktop mats (also from Ikea) to keep my eyes "calibrated". They also work well as large (70 x 40 cm or 27.5 x 15.5 inches) mouse mats. WORKING LIGHT It's bad practice to illuminate your work area with fluorescent lights - unless you are certain that the tubes you are using are special photographic-quality daylight balanced. Nor is it a good idea to work in natural daylight, switching on the incandescent room lights when dusk falls. The light you use to light your work area is particularly important. What you should have is a work area with carefully controlled illumination, falling on the . This need not be expensive. I use a small tungsten-halogen spotlight with a colour temperature of 3200K (actually, it's just under this). On it I use Lee Filters' "Half CTB" (Colour Temperature Blue) lighting filter to raise the colour temperature to mid way between tungsten (3200K) and daylight (about 5500K). After years of experimentation, I have found that I prefer this mid-way solution. Examine the colour filter at regular intervals and change it if it begins to fade. SET UP YOUR MONITOR'S GAMMA Next set up your monitor's gamma using the Gamma utility which comes with Adobe Photoshop. You will probably find this file hiding in Photoshop's "Calibration folder". Move it to the "Control Panels" folder, restart your computer, and then open Gamma.   Click the "On" button to make Gamma active. "Target gamma" should probably be 1.8, though some monitors may need one of the other Target Gammas. Find out by experimentation - you can't do any damage. Click the radio button to select this. Then, looking at the bar of alternating grey boxes just above it, drag the Gamma Adjustment triangle to the left and right until the alternating greys all look the same shade. It may help if you half close your eyes when doing this, to blur the patterns in the grey boxes. When you are happy, click the "Save Settings" and save your settings in a file, in case you need to re-load them in the future. Then click at the top left to close the Gamma utility. Need any more information? You'll find it in your Photoshop manual. IS YOUR MONITOR SHOWING YOU EVERYTHING? Now ensure that you monitor is displaying all the 256 levels of each of the primary colours which your computer can generate. You need a RGB mode greyscale from black to white in 5% steps to do this. Here's one that you can download from us. Just point at this image with your pointing device, click and hold, then save the image. It will be saved as a 525 x 25 pixel GIF image. Convert it to RGB (in Photoshop, select "Mode", then "RGB Color"). This image is a convenient size to sit at the bottom of your monitor while working in your favourite image editing application, providing a constant reference greyscale. Note that there are two greyscales, running in opposite directions. Mid grey is where the upper and lower squares are identical tone. With this greyscale, the monitor can be set up using nothing more than the brightness and contrast controls, so that you can see every one of the patches from black through to white. It is as simple as that: your computer cannot generate anything less than 0 (which is black), nor more than 255 (which is white). Mid grey is 127 or 128, as near as possible to half way between 0 and 255. You can measure the light output from each of the patches on your monitor and plot a graph of the monitor's gamma. I use an old SEI Photometer for this. GREYSCALE TRACKING The greyscale also gives an indication of the "grey scale tracking" of the monitor - how well it reproduces greys by mixing together red, green and blue light within the cathode ray tube, without introducing a colour cast into any of them. If there is a colour cast, this can be neutralised using the Gamma utility to adjust the overall neutrality (Balance) and the neutrality of the Black and White Points: Click the appropriate radio button (the "Balance" button is selected in the illustration) and drag the triangles along the lines to adjust red, green or blue. The eleven-chip greyscale in the Gamma utility helps you judge the effect of your adjustments, all of which are software adjustments - easy to cancel if you don't like them. EACH AND EVERY BIT The next chart contains all the greys tonal values (greys) which computers can display, together with how many computer bits are required to describe them. Unfortunately the 64, 128 and 256 greys will probably all display at only 32 levels only in your browser - that's one of the limitations of the WWW. What you need to do is view the image off-line in your favourite imaging package. To download, point at the image with your pointing device, click and hold, then save the image. It will be saved as a 502 x 124 pixel GIF image. Convert it to RGB colour (even though it is a monochrome image - in Photoshop, select "Mode", then "RGB Color"). Make sure that you monitor is set to "Millions" of colours. The "2 tonal values" are simply black and white, achieved in computers by devoting just one bit to each screen element. This kind of display was used in early computers. Note that the number of tonal values doubles for each addition bit devoted to describing each pixel. Displays which devote 24 bits to each screen pixel use 8 bits per primary colour and can display 256 levels of grey, made up by mixing equal amounts of the primaries. But 24 bit displays are able to display a staggering 16,777,216 different colours - all the combinations of 256 discrete levels of each of red, green and blue - for each pixel in the image. If you have a 24 bit monitor, the bottom band of this image should appear as a continuous gradation from black to white or white to black. This is what is termed "photo-realistic": the steps are so close together that you cannot distinguish them. Unfortunately, CompuServe GIF format images can only hold 256 colours. This is fine for our test charts (which contain 256 or fewer colours) but not sufficient for photographic quality. COLOUR BARS AND GREY SCALE Your computer monitor has three electron guns which excite only their respective red, green and blue phosphors on the inside of the face of the tube. All other colours are made by combining these three colours in varying amounts. To download this image from us, point at the image with your pointing device, click and hold, then save the image. It will be saved as a 640 x 480 pixel GIF image. Convert it to RGB (in Photoshop, select "Mode", then "RGB Color"). This file combines a grey scale with electronically generated colour bars, just like the ones used in television. The saturation of the light primary colours - red, green and blue - is the maximum you can generate in the computer: level 255. The light secondary colours, which are also the pigment primaries - cyan, magenta and yellow, are also at maximum saturation. White is made up of equal and maximum amounts of all the light primary colours. Black has zero amounts of the three primaries. Here's how the colour bar colours are made up: The colour bars are useful as one of the tests for colour printers, which convert RGB images to CMYK - Cyan, Magenta, Yellow and Black. In colour printing, Black is usually referred to as K (for "Key"), rather than B, to avoid confusion with B for Blue. You may be surprised how dull a print of colour bars looks. Using four colour printing, blue reproduces much darker than on a cathode ray tube. Green is also on the dark side and there is little difference between magenta and red. In colour printing, Red is made by adding yellow to magenta. THE REAL PICTURE Finally, we bring you a real picture. After all, that's what you will ultimately be looking at on your system. You should now be able to see the full range of tones in this image. (This image was taken on a Kodak DCS420 digital camera.) The pictures which you see every month in my "Chip Shop" column in "The Photographer" are judged on monitors lined up in exactly the same way I have recommended here. In a future feature we will describe other methods to get still closer to perfection. - John Henshall