Thursday, September 14, 2006

The quality of light

Very often I'm asked by students why the color of the same object may look different in 2 consecutive pictures?
The more obvious reason is the usage of the auto white balance on the camera, but in some occasions, we found the flash used to be defective. If the flash does not send the same amount of light each time, it can do so by changing the intensity or even the voltage to light the flash tube, sending a different light temperature.
Even if you use a ColorBalanceCoach disc to set your aperture, if the flash varies its power from time to time, even the best calibration tool will not allow you to take perfect pictures.

Take a look at the best affordables and reliable flashes on the market: Aurora

Jean-Francois O'Kane

Color Balancing or color correcting

Would you rather Color Balance once at picture taking time or color correct all night after a shoot?
Or: Who painted my wall yellow?
The digital era brought with him a whole lot of fun things, unlimited shootings, everlasting roll of film and perfect auto modes. Oups! I'm starting to talk like a salesman. The auto-everything camera is not out yet.
Let do the test: ask your best subject to stand in front of a white wall while wearing a red sweater take a auto-exposure and white balance picture, now change for a green sweater and shoot and try a blue one after. Then look at all 3 pictures side by side on your computer screen.
The red sweater has a “greenish” wall, the green is on a “reddish” wall and the blue on a yellowish wall. Hey? Where is my white wall? The auto mode ate it! Or painted it!
"Color Balance" / "white balance" these 2 expressions are synonymous and can be used indifferently; because if you set your white to be exactly white, then your colors will be on target.
The auto exposure and color balance features in a camera are set and programmed to look for neutrality, the exposure will try to make everything grey, to prove it aim at a white wall with nothing on it , shoot and you get a grey picture; while the auto white balance (or color balance) will look for an equilibrium of color it may be programmed to look for a white wall but if you place in front of it a big red patch it will try to find the balance in your picture and to compensate for an abnormal area of red will try to compensate by adding green, the opposite color.
To fight the wall painting monster you will need a white balancing tool and an exposure control tool. A new product is available:
The solution is the ColorBalanceCoach disc , it will assist you in performing incident or reflected white balance, your exposure and the full calibration of your image by using the displayed histogram. To use it: Set your camera on manual. Set the exposure on the grey patch. Take a picture of the ColorBalanceCoach using the setting you just measured, then check the histogram, you should see 4 separated peaks, not touching neither end. Make a custom white balance on the grey patch or through the translucent white patch, set it as the working white balance . Shoot!

TheStudioCoach's TIPS on white balance:

--2 minutes of your time to do a good white balance at picture taking, will save you hours of color correction afterward

--Learn to look at your histogram, it will tell you the thruth. Your LCD display behind the camera may not be exact.

--Get a color balancing solution that fits your camera bag, you then have no excuse for to taking it along on photo trips.

Jean-Francois O'Kane,