 Alexis Paul |
How to light a white backdrop I am having some probelms making a white backdrop come out completely white. It tends to have a little greyish hue. I have tried having the subject far and then really close to the backdrop. I sometimes use 2 norman light with umbrellas, and sometimes one light with a reflector. If any could help I would forever be greatful. Thank you Alexis:)
|
|
|
|
||
|
Mike Carpenter |
shine a light on your backdrop. the backdrop needs to be brighter than your subject.
|
|
|
|
||
|
Alexis Paul |
can I just use a single light above the subject pointing down behind them. I want to do full lenght thanks for the response
|
|
|
|
||
|
Alan N. Marcus |
To achieve a white background, it is not enough to have a white backdrop. Stated another way; unless you light and expose the background to achieve white, you won’t get white. What is needed is a background light. This is a lamp placed behind the subject and adjusted to illuminate just the background. You achieve white only by correctly adjusting the brightness of this lamp. If non-adjustable as to intensity, you must use distance as the basis for the adjustment. It is unlikely that you can evenly illuminate the background and achieve a uniform white with a simple lamp. This uniformity can only be obtained using a “broad” source as outputted by a bank of highly diffused lamps. An umbrella lamp is close but no cigar. For white, you need to light the background quite brightly. You should experiment with different lamp to background distances. Use placards to help you identify distance used as you make an exposure series. Start at say 8 feet (96 inches) lamp to background distance. Multiply this distance by 0.707 for next placement i.e. 96 x 0.707 = 68 inches rounded, next will be 68 x 0.707 = 48 inches, etc. The 0.707 multiplier produces a series, each 2x brighter (1 f-stop) brighter. One of these distances will be just about right to achieve desired white. Now for the subject lighting: First the “fill” lamp: Draw an imaginary line between subject and camera lens. The line passes through the camera lens and beyond. Your “fill” lamp should be situated as close to this line as possible. Place “fill” to shine on the subject, off to the side only enough to avoid obstructing the cameras view. If behind the camera, position off to the side just far enough to avoid casting camera shadow on subject. Don’t fool yourself and not follow this advice. You are filling shadows from the camera’s prospective not from the viewpoint of some off axis observer. Measure and record “fill” to subject distance in inches. Place “Main” high and off to side (side hair is parted on usually best) turn off “fill” while adjusting position of “main”. Watch subject’s shadows as you move the “main” for effect; long nose short shadow – short nose long shadow. Round face move main forward so that side of face is in shadow. Long face – more towards rear to avoid shadow on side of face etc. Note “fill” to subject distance in inches. Multiply “fill” distance by 0.707 this is “main” to subject distance for 3:1 ratio. Remember, “main” must be brighter than “fill” therefore closer. Stated another way: “Fill” is always subservient to create an illusion of only one light that simulates the sun. Example: “Fill” 72 inches from subject, “main” is 72 x 0.707 = 51 inches. This assumes “main” and “fill” are equal in brilliance. Multiply again, this position, 36 inches produces a ratio of 5:1, again and ratio becomes 9:1 at 25 inches. To set exposure, measure face with a meter with only the “fill” operating. This assumes you are using the 3:1 “bread-and-butter” ratio, so called as it is proven to be the best seller. This technique sets the exposure 1 f-stop over exposed when the “main’ is operating. Technically this is necessary as the average human skin tone lighter by about 1 f-stop than the 0.75 density (18%) the meter is factory calibrated for (zone 5). This technique places human skin on zone 6 of the zone system scale which results in a more natural shade on the finished print is the result. Photography is both art and science. You are fooling your self if you don’t think this is the case. If you don’t study the science, you are doomed to re-plow fields that have been plowed over-and-over by others. Sometimes that not so bad, old farts are often wrong. However, everything in photography has a logical why! Ask yourself and others, again and again until you get a logical answer. Alan Marcus ammarcus@earthlink.net
|
|
|
|
||
|
This old forum is now archived. Use improved Forum here
Report this Thread |
||