Triggering Options

SLR Booth provides a number of options for triggering the countdown, allowing for flexibility and creativity when it comes to creating your photo booth setup.


If you’re using a tablet or all-in-one with a touchscreen, then using the touch is probably the way to go. Just press the button with the camera icon on the screen, and the countdown will start.



SLR Booth will also respond to the space key being pressed. This can be sent from a standard USB or bluetooth keyboard, but another great option is to use a USB foot pedal programmed to send the space key.


Bluetooth Remote

There are several bluetooth camera remotes on the market that operate by sending the volume up key – SLR Booth will function just fine with these to start the countdown.


SLR Booth Remote App

If you have an extra Android phone, you can install the SLR Booth Remote app, and it can function as a basic UI with a few more features than a simple button – it can trigger and cancel the countdown, and also supports approving/deleting images after they’re taken. This works great when running the main app on an HDTV & Android TV box – users get a big screen to look at, but can still use a touch interface.

Focus Settings for Photo Booth operation

One of the most important factors in how good a photo looks is the focus. It doesn’t matter how great a subject or the lighting looks in the photo, if the focus is off then the photo isn’t worth keeping.

  • Modern DSLR cameras used with SLR Booth Support at least 3 focus modes:
  • Phase detection auto focus
  • Contrast detection auto focus
    Manual focus

Some new cameras such as the Canon 70D and 7D mk II support a hybrid auto-focus, but we’ll concentrate on these three main types.

Phase detection auto focus is the standard focus system for DSLR cameras. It is very fast, and quite accurate, but only works with the camera’s mirror down. When SLR Booth is running and showing a live-view preview, the mirror is up, so if this method of autofocus is used the camera must drop the mirror to focus, perform auto focus, then raise the mirror to take the picture. This flipping of the mirror up and down adds a bit of shutter lag and noise, but results in fast, accurate focus.

Contrast detection auto focus is used by DSLRs when running in live view mode. It is typically slower than phase detection to lock focus, but it doesn’t need to move the mirror. So while focusing is slower, there is less shutter lag. Some cameras will also do automatic face detection in this focus mode, which can be very helpful for a photo booth.

Manual focus is done by the photographer, rather than the camera. The benefit to manual focus is that there is no shutter lag, and you get consistent focus between shots. The downside is that your subjects have to be in the same place each time for this to work. Luckily, in a photo booth setting, this is actually pretty easy to accomplish. If shooting with a crop-sensor camera with at 24mm, and the apeture set to f/8, set the focus point to 6 feet and then everything between 4 feet and 11 feet will be in focus. Just place a mark on the floor 6 feet from the camera, and have the subjects stand there.

Personally, I only ever find myself using phase detection and manual focus: Manual when using a foot-pedal trigger, and phase-detection otherwise. Just remember to change your shutter delay in the settings when switching between focus modes!

Exposure Settings for Photo Booth Operation

Cameras are designed to make exposures. Every time you hit the shutter button, the camera samples the incoming light, and turns this information into a photo. To get a correct exposure on your photo, the sensor must recieve a certain volume of light.

This “volume” of light is controlled by three factors:

  • The size of the opening (aperture)
  • The length of time for the exposure (shutter speed)
  • The sensitivity of the sensor (ISO)

When your camera is in manual mode, you are in control of all three variables. Switching your camera to any other mode, and it will figure out one or more of the variables for you, based on the built-in light meter. For a photo booth, you should always be in manual mode to get consistent lighting between shots. And if you are using a manual flash, the camera’s meter will be wrong anyways.

Take an example of an outdoor photo on a brightly lit day. The “Sunny 16” rule tells us the correct exposure is:
F/16, 1/100 s, ISO 100

Say we had this exposure, and the photo was too bright. We could darken the photo by one stop by either:
Closing the aperture down to F/22
Speeding up the shutter to 1/200s
Lowering our ISO to 50 (assuming we have a really nice camera where ISO 50 is available)

What if it was too dark? We could do one of the opposite changes:
Open the aperture up to F11
Slowing down the shutter to 1/50s
Increasing our ISO to 200

But, we could even keep the exposure the same, and change some of the variables, so long as we also make the opposite change in one of the other variables:

We could open the aperture up to let more light in, and compensate by having the shutter open for only half the time:
F/11, 1/200 s, ISO 100

Or, we could close the aperture down to let less light in, and compensate by have the shutter open twice as long:
F/22, 1/50 s , ISO 100

All 3 of these exposures are equivalent. In fact, there’s an incredible range of values that would provide the same exposure, all the way up to the physical limits of your camera. So, the question becomes: which settings should one use for a photo booth?

Each of the variables we adjust have tradeoffs that occur when we adjust them:
Moves in units called “F-Stops”, which are half-powers of two. Full stop changes are: F/1, F/1.4, F/2.0, F/2.8, F/4.0, F/5.6, F/8, F/11, F/16 …
Aperture controls depth-of-field (DOF). Depth of field describes how far in front and behind the focus point will remain in focus. When we use a very large aperture (say, F/2.0) the depth of field may only be a few inches, but if a very small apeture is used (like F/16) then there may be several feet of depth in focus. While a shallow depth of field can yield a pleasing out of focus background for a portrait of a single subject, for practical purposes a photo booth works best when everyone is in focus, even if they aren’t exactly lined up. Suggestion: Use a aperture around F/8. This gives a good balance between sharpness and depth of field.
Shutter speed
Expressed as time, again moving in “stops” that are either half/twice as long depending on which way you move. Full stop changes are: 1/4000, 1/2000, 1/1000, 1/500, 1/250, 1/125, 1/60, 1/30, 1/15 …
Under natural lighting, shutter speed will control how much motion blur is present in your photos. Speeds of 1/125 to 1/250 will eliminate most blur in stationary subjects, but isn’t fast enough to “freeze” quick motion. Slow the shutter to the 1/30 range and you might start seeing your subjects blurred. Most photo booths will want to use some sort of flash lighting, and this happens incredibly quick (like 1/1000s), so if using a flash, just make sure your camera’s shutter is set to slower than this. Suggestion: Set the flash to the Camera’s maximum flash sync speed, usually between 1/125 and 1/250.
100, 200, 400, 800, 1600, 3200, 6400…
The sensor sensitivity (ISO) controls how much digital “boosting” is applied to the image. The more boosting applied, the noisier or grainier the image will appear. Suggestion: Choose ISO last after setting aperture and shutter speed. Pick the lowest ISO value that will work with your flash at a reasonable power.

TL;DR version:
For the average photo booth, the following settings should be a decent starting point:

  • Aperture: F/8
  • Shutter: 1/125
  • ISO: 320
  • Flash: 1/4 power

If the photos are too bright, reduce flash and/or ISO.

If the photos are too dark, increase flash and/or ISO.

5 Things to check before you start a photo booth session

5 Things to check on your camera before you start a photo booth session:

  • Picture format – Probably want RAW if you’ll be editing the files afterward, JPEG is fine if  you’ll be using the photos straight out of the camera.
  • Picture size – Full size images are best for large-format printing, but if you’ll only be sharing on social media then medium or small images will transfer much quicker, and still look fine on screen.
  • White Balance – Set to flash if using flash, otherwise, match to the ambient lighting conditions
  • Exposure Settings – Should be on full manual to have consistent exposure between shots
  • Memory Card – Make sure it’s loaded and formatted!