I often use the modelling light function with my Canon Speedlite flashes. At my recent workshops I was pretty amazed to find out that many Canon EOS camera owning photographers didn’t know that a modelling light was built in to many of their Speedlites; for me it’s a really useful feature.
Speedlite modelling light
Press the depth of field button next to the lens on most EOS cameras and the viewfinder gets darker as the lens stops down to the chosen aperture. However if you also have a Speedlite on the hotshoe or Speedlites off-camera controlled by a master flash then you can use the modelling flash feature.
Pressing the depth of field button causes the flash(es) to emit a few seconds of continuous light. This is the modelling light and it gives both a photographer and model a guide as to where the light will fall in the picture.
I use the modelling light so I know where the light will be and I often ask my models to check if they can see the light coming from a flash which has a grid or honeycomb fitted. If they can see the light then I know that it is lighting them directly on their face.
In the case of the image to the left, I had a single Speedlite positioned as high as my light stand would go. The Speedlite was zoomed to 200mm to give a small spot of intense light on the floor, and I used a tight honeycomb grid to give a fast fall-off of light. Using the modelling light I could see where the spot of light would be and so could the model.
In this case the room lights were quite dim, and my shutter speed was making the room go dark, but to our eyes we couldn’t determine the exact placement of the spot on the floor without using the modelling light function.
Modelling light options
The modelling light is a function of the Speedlite not the camera, and it can be deactivated with a Speedlite custom function C.Fn 2.
With a suitable external Speedlite master on the camera, go to the External Speedlite or Flash Control menu on the camera, scroll down to the Flash C.Fn settings menu item. Then select C.Fn 2 to change how the modelling light behaves.
In the screen grabs above I have a Speedlite Transmitter ST-E3-RT on the EOS 5D Mark III, hence the relatively limited range of custom functions. The list will change depending on which flash you have on your camera.
Disabling the modelling light might seem a bit drastic, but if you need to avoid any inadvertent modelling light then it’s possible. Some photographers find that with the modelling light function connected to the depth of field preview button they inadvertently press the button when holding the camera by the grip. With the custom function it is possible to re-assign the function to the flash test button.
A cautionary note…
Don’t forget that the modelling light function is something to use sparingly. It uses a bunch of power, and it heats the flash tube. There are warnings in the Speedlite instruction manual about repeated over use.
Built-in Speedlite master = no modelling light
If you have one of the cameras that have a built-in Speedlite transmitter function using the pop-up flash you won’t be able to activate the modelling light function. You will need to put a regular Speedlite master flash on the camera hotshoe.
The following cameras have a built-in Speedlite transmitter at the time of writing; EOS 600D, EOS 650D, EOS 700D, EOS 60D, EOS 70D, EOS 7D.