Color Calibration on the Cheap
There are plenty of expensive ways of calibrating your system for color output. Problem is that they're a) expensive, b) not always compatible and c) intended for CMYK output. If you want your slides to look reasonably close to what you see on your monitor, you may find that you're "out of the loop" when it comes to calibrating your system.
The only 100% accurate way to ensure that you get the colors you want is to do actual tests. Make sample "color chips" in the software of your choice and have the images made into slides. And yes, we know that this isn't always practical, so we've come up with an alternate method. Like any calibration method, it's not completely accurate, but even if it won't ensure a home run every time you're at bat, it'll at least put you in the right ballpark.
Why don't the colors match and what can I do about it?
Your monitor and the device that prints or displays your slides use completely different technologies to produce color. It should come as no surprise that the colors they produce are sometimes different. In fact they almost certainly WILL be different.
Here's a test image
This is an image we used to use for testing and calibrating.
Rightclick this link and choose Save target As to download RDPCAL.TIF (our 99k test image) - You'll need it a little later on.
It contains a wealth of useful information. We originally developed it back in the 35mm slide days, so you'll notice it's in 35mm slide proportions and contains a couple of slide-specific features. Still, it can be useful for other purposes. Here's a quick explanation of what each part of the image tells you.
1. A series of rectangles stepping in from the outer margin at 1/16" intervals
Printers and displays don’t all produce exactly the same size image and each may position the image differently. The rectangles at the edge of the image can help you determine where the image is getting cut off or not filling the frame.
2. and 6. Black-to-white 255-step gradients on black and white backgrounds
Sometimes gradients "break" differently on different output devices. This will give you an idea of how gradients will appear on your monitor and elsewhere. Gamma adjustments, if available, may help improve the appearane of the gradients.
3. Black patch test
This is a series of squares evenly spaced from 5R 5G 5B to 50R 50G 50B (nearly black to dark gray in steps of 5) on a black background.
It'll help you adjust brightness of both your monitor and projector. The goal is to have the darkest square just "lift" visibly off the background
4. Pure colors
This is a set of pure red, green, blue, cyan, magenta and yellow patches and 0 to 100% gray patches (in steps of 10%).
Your monitor/projector/printer settings may permit you to adjust color and gamma. These patches provide a target to adjust to.
5. White patch test
Just like the black patch test, but for the light end of the scale. This is a series of squares evenly spaced from 253R 253G 253B to 235R 235G 235B (nearly white to very light gray in steps of 2) against a white background.
The goal is to adjust your monitor and projector so that the lightest patch is just visible against the white background.
Calibrating your system
- Use Insert, Picture, From File to bring RDPCAL.TIF into Powerpoint. Fill the slide with the image.
- Adjust your monitor's contrast and brightness so that the darkest black patch and lightest white patch are just visible against their backgrounds. It may take a little back-and-forth fiddling to accomplish this, since contrast adjustments have an effect on brightness and vice versa. You'll get there faster if you first set the brightness so that the correct black patch is visible against monitor black, then adjust contrast so that the correct white patch is just visible against the white background.
- If your monitor allows it, adjust the color to get the purest possible colors in the color patches
Then when you're ready to project a presentation, use the same steps to set up the projector, this time adjusting the projector's contrast, brightness and other controls to get the best possible match to the test slide.