How can I get a black background when using flash?

Asked 1/5/2018

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I’m using a Canon EOS Rebel T5 and want my subject lit by flash while the background stays very dark or black. When I use flash now, the background gets brighter too. What camera settings and lighting setup help keep the background dark and emphasize the subject?

Originally by Photography Stack Exchange contributor. Source · Licensed CC BY-SA 4.0

Photography Stack Exchange contributor

8y ago

2 Answers

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This is simple: more distance. Light falls off with the square of the distance from the flash, so it doesn't need to be a huge, but the basic idea is to get the background far enough away that the flash doesn't light it effectively.

If you are distance-constrained, you can use an external flash to the side and "flag" it — that is, block some of the light with a piece of cloth or cardboard or similar — so less is directed towards the background. That'll buy you a little more space, but since light bounces around, you still need some room.

You'll also need to make sure your flash is the primary source of light — you'll want to use the camera's flash sync speed and probably use a narrower aperture and more powerful flash, so that the room lighting is irrelevant.

Originally by user1943. Source · Licensed CC BY-SA 4.0

user1943

8y ago

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AI Answer

Generated from our catalog & community — verify before relying on it.

To get a black background with flash, you need the background to be much darker than the flash-lit subject. The key is controlling the ambient/flash ratio: without flash, your test shot should be very dark or nearly black.

What helps:

  • Reduce ambient exposure: use low ISO, a narrower aperture, and your camera’s flash sync speed.
  • Make flash the main light on the subject.
  • Increase subject-to-background distance so the flash falls off before it reaches the background.
  • Control flash spill: an off-camera flash placed to the side works better, and you can flag/block the flash so less light hits the background.

This works because flash intensity drops quickly with distance, so a subject close to the flash and far from the background will be much brighter than the background.

Limits:

  • In bright ambient light, especially daylight, it can be difficult to make the background go fully black.
  • A black background is often easier indoors or at night.

So: darken the ambient exposure first, then light only the subject with flash while keeping the background farther away and out of the flash beam.

UniqueBot

AI

8y ago

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