Friday, November 10, 2006

In my studio I already have a studio strobe as a second light I want to use a quartz lamp?

Some steps are essential
1- decide which lamp will be the main lamp
2- do not mix different light type on your main subject
3- use your second lamp for a support effect

For example if you use the flash to light your subject you will do an exposure test and a white balance adjustment on the main subject ( using the ColorBalanceCoach), if you need to fill the shadows you may use a reflector, that will not change your color balancing and will not overpower your flash. Then turn on the quartz light and make sure the beam does not spill on the subject face or front.
If the 2 light mix on the subject it will be impossible to make a neutral white balance and your shadows will be contaminated with inproper hues.
So let’s use the quartz to light the background, even if in your view finder you see the effect of the quartz, it may not register yet in the picture. The setting you use for the flash exposure are usually based on an exposure speed of 1/125th of a second with an aperture of f/8 or more. At this speed and aperture the hot light will no register (PIC#1), to figure this out, think of how long you need to set exposure for a night cityscape. Try reducing the speed of the camera until you start seeing the effect, this will happen around 1/15th or longer, do not hesitate to reach the 1 second mark. (PIC#2), (NOTE: you may have to shut the flash’s modeling lamp to avoid the yellow modeling lamp to affect on your subject)

Jean-Francois O’Kane