Don't Swat the Spyder - He's Your Best Studio Friend
The grey card is one of the most useful of devices to judge accurate exposure with. No matter how much confidence we have in the software of our camera, there are times when it can be fooled and we need to be able to correct its errors. If we use a grey card we can find the 18% reflectance point that gives our meter the best chance of an even exposure.
If we also have access to a pure black tone and a pure white tone in our image we can tell our computer exactly how far to go for the image that it alters.
Finally, for the ultimate of contrast control, we look for the ultimate specular highlight and absolute shadow. But frequently in the subjects that we encounter none of these attributes are to be found. We find ourselves basing our decisions in the studio, field, and computer room on uncertain things and sometimes can never seem to get a pure photo, no matter what slider we shift.
Enter the Spyder Cube. It has 6 working faces as well as a specular highlight collector and and a absolute shadow point . You can dangle it near to your main subject or screw it onto a tripod so that your camera sees it in the same light. One or tow test shots to the grey and you've got the basic exposure, and when you get the test shots back onto your computer screen you will have the whole range of tones there to adjust to; specular, white, 18% grey, black, and absolute black.
Here's the key to what you see:
A. As bright as it will ever get. Pure white from the strobe tube.
B. The 18% grey.
C. The white that you have to deal with in the lighting situation you are in.
D. The black you have to deal with with the lighting as it is.
E. As black as you can ever get it.
The Spyder Cube is small enough to pack for the field and fast enough to deploy in any studio shoot - and cheap as chips compared to frustration time spent whacking sliders back and forth!