Beginners Guide to Using TTL Off-Camera Flash

Beginners Guide to Using TTL Off-Camera Flash


So you want to use off-camera flash. But why? Your camera has that hot shoe there for a reason, right?

There are two things that you may not realize:

  1. That many DSLR-speedlight combos are capable of wireless off-camera flash using through-the-lens (TTL) metering without any additional equipment
  2. That using off-camera flash can take your photography to an entirely new level both in quality and creative potential.

Many references to off-camera flash talk about sync cords and wireless transmitters, when in fact, many DSLRs with a built-in pop-up flash have the ability to wirelessly control a speedlight. Likewise, many hot shoe mounted speedlights are fitted with an optical receiver to be wirelessly triggered.

Image of pop up flash and speedlight optical receiver

Look, no wires! On camera pop-up flashes are often capable of optically triggering speedlights.

The least painful way to cross the proverbial bridge into the realm of wireless off-camera flash – often referred to as a remote or slave flash – is by utilizing your camera’s ability to act as a remote trigger for a flash combined with TTL metering.

Most Nikon cameras from the D70, and flashes from the SB-R200 and up; and Canon cameras from the 600D (T3i) and flashes from the Speedlite 90EX and up offer these features, but check the manufacturer’s website to be sure what setups will work. There are also a wide selection of other brands of flash, often less expensive, that offer similar features.

A TTL-equipped flash is manufacturer specific. The TTL feature of a Nikon dedicated flash will only work with Nikon, however, it could possibly still be used in manual mode.

In a nutshell, TTL is the way that the camera sets the exposure and flash intensity automatically by firing a nearly imperceptible pre-flash, taking an exposure reading, and adjusting settings accordingly. Nikon calls it i-TTL and Canon has dubbed it e-TTL but it’s basically the same deal.

For wireless off-camera flash functionality, the built-in flash on your camera is set to send an optical signal to your flash which triggers it.

Photo taken with a hot shoe mounted flash

This photo was taken simply with a hot shoe mounted flash set to TTL metering and the camera set to aperture priority. Shot at 200mm, f/5.6 at 1/60th of a second with the flash pointed at a low white ceiling. Nice soft, even lighting.

Photo taken with off camera wireless flash

Exact same settings as the photo above except the flash was setup off-camera in remote mode, with TTL metering. It was placed at 45-degree from the subject and aimed towards the food. Voila! Directional, moody lighting.

First time users of this method will think they just discovered sorcery. Partly because it’s such a cool trick and partly because it is easy to achieve awesome results right away. Manually controlling an off-camera flash isn’t the end of the world but it requires more thought and consideration to balance the flash and camera settings to achieve desired results.

If you have a camera and a hot-shoe-mounted flash unit that are capable and you haven’t taken advantage of it yet, this is the point where you should start getting excited.

Setup for Nikon Equipment

Camera Settings (menu locations may vary depending on camera model)

  1. Open the Custom Settings Menu
  2. Scroll down and select menu “e” – Bracketing/flash
  3. Choose e3 on the list – Flash cntrl for built-in flash
  4. Choose the last selection on this list – Commander mode
  5. The first line item is Built-in flash, scroll right to highlight the Mode column. If you haven’t messed around with this it will probably be set to TTL.
  6. Scroll down until it reads – –. This means that the camera’s built-in flash will only trigger the off-camera flash and won’t add any additional light to your exposure.
  7. No need to change it but note what channel is selected as your flash will need to be set to the corresponding channel.
  8. Press OK.
  9. Pop open the built-in flash.

Flash Settings (varies depending on flash model)

Photo showing SB-600 remote flash setting

Users of Nikon speedlight models SB-600 and SB-800 are looking for this symbol indicating the flash is ready to be wirelessly triggered. The SB-800 selection is also marked Remote.

On some Nikon flashes you are looking for a curved arrow symbol that signifies it is set to be controlled wirelessly. On some models like the SB-600 and SB-800 this is accessed in the Custom Settings menu while the SB-700, SB-900 and SB-910 have a dedicated switch to set the flash to Remote.

Setup for Canon Cameras

Camera Settings (may vary depending on camera model)

  1. Press the Q button to open the menu.
  2. Cycle through until you reach the Built-in flash func. menu setting identified by a flash symbol. Press the Set button to select.
  3. Choose the middle menu item called Easy wireless flash shooting. This setting can also be found in the first page of the shooting menu under Flash control.
  4. No need to change it but note what channel it is set to as your flash will need to be set to the corresponding channel.
  5. Pop open the built-in flash

Flash Settings (varies depending on flash model)

On Canon a flash you need to set it to slave mode. Some Speedlite models have a dedicated switch for this setting, and others require you to hold down the zoom button to switch it on.

The system is an optical one, meaning that the receiver on the speedlight needs to “see” the signal from the on camera flash. A direct line of sight is recommended but I have found that you can often hide the speedlight slightly behind a wall or other object, and it will still receive the signal.

Other than the signal being interrupted by physical objects, it can also be finicky in bright daylight, and the range is limited compared to radio frequency triggers.

Food photo with off camera flash

Simply getting the flash off of the hot shoe and a couple of feet to the side casts more visible shadows and gives the photo more dimension.

Editor’s Note: If you have a system other than Canon or Nikon consult your camera and flash manuals for the settings. We apologize if you feel left out, but we are not able to cover every brand and combination in the scope of one article. 

Notwithstanding the limitations of the system, it’s an ideal introduction to off-camera flash with minimal investment of time or money – especially if you have the equipment already.

These are the very basics. Both Nikon and Canon systems are very flexible, and expandable, with the ability to adjust flash intensity from the camera, add additional flashes in groups, and in some cases, trigger other flashes from a master flash adding more versatility and utility.

After you get the system working its magic and have officially entered the  realm of off-camera flash, there are innumerable adjustments to make both on the flash and camera to gain more control, and fine tune your lighting to create the photo you see in your mind.

A Few Quick Tips

  • Very bright ambient light and flashing lights can interfere with the optical triggering
  • For best results, point the receiver window on the flash (usually covered with red plastic) toward the camera and rotate the flash head if necessary
  • If the background is too dark, try decreasing (slowing) shutter speed and/or increasing the ISO

If you want your subject and background to have more even lighting, take a look at Dragging the Shutter: Balancing Fill Flash with Ambient Light

For more technical information about flash placement, have a read of Working with Off Camera Flash and TTL.

Just starting out with off-camera flash? Let’s hear about your experience and see your results in the comments below.

Read more from our Tips & Tutorials category

Jeremie Schatz is a freelance photographer, photojournalist, journalist, copyeditor and videographer for a variety of clients and companies in the United States and Thailand. Find his portfolio of colorful images and more of his writing at Exposed World Photography and on Facebook.

  • Rob Dyer

    A really great article, thank you! I just got myself a flash and managed to get some really nice portraits with it outside. Experimenting with it was so easy after reading through DSP’s articles. Thank you so much.

  • Jeremie

    Thanks Rob and that’s great that the article was of value to you. Great pic, a little extra light can often make a good photo great.

  • eshortie103

    Great article! I just have one question will this technique work with a non canon or nikon brand flash? I’m really excited to try this. At the moment though I only have a neweer speedlite. I have used to as a slave but only when the pop up flash fires also.

  • Jeremie

    Yes, this technique can be used with all sorts of flashes if the following is true:

    -The flash has an optical receiver
    -You purchased the flash that is compatible with your brand of camera
    -Your camera has a built in flash that is capable of triggering a remote/slave flash

    You will need to check the user’s manual for your camera and flash to confirm. Please let us know what brand and model of camera and flash you are using and what you find out so others may learn from your experience. Thanks!

  • eshortie103

    Ok I will do some research this week. I have a canon 60d and the flash is a neeweer tt560 (its a manual flash). I know that my camera triggered the flash (slave mode) when I also fired the pop flash. Im just not sure if itll having the pop up flash not actually firing will work.

  • Gary

    I tried this but my camera’s (D7000) built in flash still flashes along with the remote SB700. Why is that?

  • Jeremie

    Gary, when optically triggering a slave flash with the camera’s built-in
    flash, those quick little flashes emitted from the camera’s flash are
    what actually trigger the slave to go off.

    When the camera’s
    flash is set to only act as a commander, the flashes it emits are not
    part of the exposure – no light is emitted when the shutter is open.

    This screenshot shows the menu for the built-in flash settings (this should look similar on your camera). Under Mode, where the two dashes are shown, you can change this to TTL and then the built-in flash WILL be part of your exposure. This can be pretty handy if you want to add a little direct light in addition to the slave flash to fill in some shadows. Hope this helps.

  • Gary

    Thanks Jeremie. But not sure this helps. I hope I got it right. Under Commander mode the Built in Flash is set at – -, Group A is TTL, Group B is TTL and the Channel is 1. The SB700 is set to Remote and the Channel is set to 1. Camera pop up still flashes along with the SB700 when I hit the shutter release. If this is the way it should be, then I guess I got it right. Thanks again.

  • Jeremie

    Yes, that is the way it should be. Try taking a photo of something with those settings then change the – – to TTL and take the same photo. This should show you the difference between having the built-in flash included in the exposure (TTL) and only using it to trigger the slave (- -).

  • These articles are always bias towards Canon/Nikon brands
    be nice to hear more about other big brands out there: Sony, Minolta etc..
    Particularly as these other brands it is usually a tricker setup to get things like off camera flash working without amounts of workarounds

  • jamesapril

    Minolta went out of business a decade or two ago. But you’re right, what about Olympus, Pentax?

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