Open

by damned truths

submit your photo


Hall of Fame
View past winners from this year

Please participate in Meta
and help us grow.

Take the 2-minute tour ×
Photography Stack Exchange is a question and answer site for professional, enthusiast and amateur photographers. It's 100% free, no registration required.

My first helpful experiments with flash started after taking a seminar with Scott Kelby on the subject. I don't recall him mentioning dragging the shutter (but he may have). But, I do recall him showing how flash technique can be used to darken the background, even in broad daylight. This could be done to the point where the background is black, even in sunlight.

Is there a term for this technique, which appears to be the opposite of dragging the shutter?

share|improve this question
    
just heard the term for that "dragging the shutter" lol :D interesting name, yours is also dragging the shutter in that sense just to the opposite direction. –  Yiğit Hür Ulaş Feb 7 '13 at 0:05
1  
Controlling the background exposure with the shutter? –  Peng Tuck Kwok Feb 7 '13 at 0:22

2 Answers 2

up vote 7 down vote accepted

I think you're looking for "overpowering the ambient light", or, more graphically, "killing the ambient".

This means using artificial lighting so bright that it outshines the regular sources, usually the sun. (Dim indoor lighting is easy enough to overpower that it's scarcely talked about, but if you really want absolute control of the light, should be considered too.)

There's a little bit of nuance to it. Stopping down the aperture (or lowering ISO) reduces ambient light and flash together, so you need faster shutter speed.

Shutter speed is limited by two things: first, your camera's shutter sync speed, and second, the duration of the flash pulse itself. The former is usually something around ¹⁄₁₈₀th to ¹⁄₂₅₀th of a second. The flash impulse itself is something we think of as very fast, but actually at full power a speedlight-style hotshoe flash can be as slow as ¹⁄₁₂₅th when you measure the T.1 duration — the time in which the flash pulse at least 10% of the peak. (Flash duration is often given as T.5 times, which are effectively the same for speedlights at fractional power.)

A leaf shutter (rather than a focal plane shutter) or an electronic shutter can provide a faster sync speed, which can help, but that's usually not an option with the equipment you probably have (or want to spend for).

So, that means you really just need a powerful flash, and there's no tricks to get around it. "High speed sync" doesn't really help, because that's effectively continuous light and therefore also reduced by shorter shutter. Multiple flash units can do it (whether in HSS mode or just to provide more light), and it helps to get your light as close as possible because of our friend the inverse square law.

share|improve this answer
    
That must be it. Now I can Google it for more info. Here is a good video, showing it being used in daylight (not extremely bright high noon, but it makes the point). google.com/… –  Jim Feb 7 '13 at 2:47
    
You can help a bit with an electronically shuttered camera. The Nikon d40 uses electronic shuttering above 1/90th of a second. With a manual flash I have successfully synced at full speed 1/4000th second. –  Phil Feb 7 '13 at 18:28

I've heard it referred to as "Killing the Ambient"

share|improve this answer

Your Answer

 
discard

By posting your answer, you agree to the privacy policy and terms of service.

Not the answer you're looking for? Browse other questions tagged or ask your own question.