Intro to Creative Flash Part 1: What is “Shutter Sync?” and What are These Other Settings?

“Pre-visualizing helps keep you on track and focused. Aim for the Photograph with a capital “P,” rather than picture with a small “p.””

French astronomer Franck Selsis. Photographed with a Nikon SB-800 flash and D200 camera. I wanted a photo of the astronomer and the sky, so I knew I needed a long shutter speed. The flash was set off camera,  manual mode at 1/32 power to expose for him. I used a 30 sec. shutter speed to expose the night sky.

My motto is “Learning Photography is NOT a Spectator Sport.”

You have to go out and try new techniques, practice with your equipment, and most importantly learn from your mistakes.

This 3 part series addresses the use of your portable flash. It covers everything from on-camera to using multiple units as a portable studio. One thing to keep in mind: It’s only complicated if you let it be, and gets easier with practice.

By understanding the fundamentals of flash photography, you can get even more creative and begin making some beautiful images.

Your portable flash is a very powerful and valuable tool to have in your creative tool box. But like all tools, if you don’t know how to use it, it might as well be a paperweight.

Let’s start with a basic understanding of your camera’s flash sync and some various camera and flash settings:

I used my Nikon SB80 and D1H for this mountain boarder. My top shutter sync was 1/500th of a second. With that, I was able to stop his flight in mid-air. Manual mode at full power.

Sync Speed:

Top (or fastest)  Speed :   The fastest shutter you can use on your camera to expose the whole frame. Simply, it’s when the whole sensor is exposed by the open shutter.

If the shutter speed is too fast, only a portion of the frame will be exposed. However, most cameras today have a sync speed of 1/250th of a second. Some go into 1/320 and rarely 1/500 (my old Nikon D1H had a top speed of 1/500).

Any shutter speed slower works just as well. Just remember, aperture controls the flash exposure, and shutter speed controls the ambient light exposure. More on this in Part 2: Using Flash with Ambient Light.

Read your camera’s manual to find out what your top sync speed is for your particular camera.

Note: Digital cameras and newer film cameras automatically default to the highest flash sync speed if the shutter speed is set too high. This prevents accidentally firing the flash and exposing only a part of the frame.

The subject was in shadow and the people below were lit by direct sun. Using the “Sunny 16” rule, I set my camera for the background and set my flash for the Iraq War Veteran climbing.

When does my camera trigger my flash?
There are two times that your flash will fire: Rear & front curtain.

  • Front Curtain: The flash is triggered when the front curtain fully travels to the other side of the film/sensor plane. That is, when you press the button, the first curtain slides to the other side, fully exposing the film/sensor, and then triggers the flash.
  • Rear Curtain: The flash is triggered when the rear curtain BEGINS to close. That is when it BEGINS its travel to the other side.

TIP: Use rear curtain sync for most of your photography.

I wanted to capture the feeling of the kids playing so I used a slow shutter then popped my flash at the end to capture the kids. Nikon D1H and SB80

Camera Settings:

  • Front-curtain sync: This is the “normal” setting and factory default.
  • Slow sync: The camera allows slow shutter speeds to be used. This is a good setting when using your flash in darker situations where a slow shutter speed will help bring out the dark background.
  • Rear-curtain sync: This is my preferred setting. This combined with slow sync gives photos a more natural appearance.
  • Red Eye Reduction: A small light that is triggered to help eliminate the “red eye” you see when using on-camera flash. It lights for a moment to close the pupils so when the main flash fires, the dreaded “red-eye” is reduced. Sometimes the flash fires a multitude of times. Many people find this irritating.
  • Red-eye reduction with slow sync: As stated, the ability to use slower shutter speeds with the addition of red-eye reduction.

The light was low during this balloon glow in Snowmass Village, Colo. As I wanted to get the excitement of the spectators, I needed to pop some flash onto them to get a good exposure.

As every flash is slightly different, I’m going to stick with generalities. What I strongly suggest is that to learn about your specific unit, grab your manual, camera, and flash. Then sit in a comfy chair and read. Then while reading about your flash, take a few shots on that setting you are reading about.

Again, photography is not a spectator sport. You become familiar with your equipment by practicing with it.

Use it indoors, outdoors, in its various modes, in low light in bright light. Just go out and practice with it.

Flash Duration:
The time at which the bulb in the flash unit is actually lit. The longer the flash the “brighter” the light.

Some typical flash duration times: These are for a Nikon SB-800
Power                Duration

  • Full                1/1050
  • 1/2                 1/1100
  • 1/4                 1/2700
  • 1/8                 1/5900
  • 1/16               1/10900
  • 1/32               1/17800
  • 1/64               1/32300
  • 1/128             1/41600

As you can see, the actual amount of light is not how much power is emitted, but how long the bulb is energized. Now do you see how flash can stop someone in mid-air? Or capture a drop of milk forming a crown? Or a bullet through an apple?

Aspen golfer Kristin Walla takes a few practice swings. The flash captured the golf club even though it was traveling at a high rate of speed.

Flash Modes:

  • TTL Auto Metering: Uses the full matrix metering of the camera to estimate the power needed for the flash unit. Very effective in quick-moving and difficult lighting situations. TTL meands “Through The Lens.”
  • Aperture Automatic: A Simple to use mode that a sensor on the flash itself. When given a basic aperture, figures out what the power should be. Some cameras use the light coming through the lens.
  • Manual: The user sets the flash output. My preferred method.
  • Repeating: The flash acts like a disco strobe. The flash fires a multitude of times during the exposure. This is a fun tool to have and play with.

Don’t let these little devices intimidate you. Practice what your flash can do, how you can control it, and soon, they can improve your photography by giving you an extra tool in your bag.

Thank your for reading

Paul Conrad

Pablo Conrad Photography


  1. very informative blog Pablo .. very very helpful !! its very educational but still so fun and the photos you included are TOP NOTCH !! i want to run right out and use my flash the right way ! thank you thank you .. never i mean NEVER stop teaching .


    1. Thanks Sweetpea.

      I’m glad you found the info helpful.

      Too many people use it on camera and only for dark rooms. They don’t think of the many other uses this portable device has.


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