How to shoot one-light portraits with an iPhone

Three different one-light portrait setups that you can shoot with an iPhone and an Innovatronix CPFlash.

Innovatronix CPFlash and iPhone XS one-light portrait

This article is sponsored by Innovatronix.

How much can you achieve with a smartphone camera and one light? In this tutorial, we will look at three completely different portrait ‘looks’ that require just a flash, an iPhone and some simple light shaping tools.

In my previous smartphone photography demonstrations I was using my Honor View 20 Android smartphone, which is a fine mid-range phone with an OK camera, but it has a single wideangle lens, making conventional portraiture difficult. Modern, high-end phones have multiple lenses, typically including a longer telephoto or ‘portrait’ with a narrower field of view. This lets you shoot from farther away, giving a more flattering perspective of human subjects. Innovatronix provided me with an iPhone XS for this demonstration; you can achieve similar results with any recent iPhone or Android smartphone with a portrait lens.

The Innovatronix CPFlash 550W is one of the only off-camera flashes that can synchronise with cameraphones. Priced $199, you might want to test the waters first with just one Innovatronix lights before investing in more. What’s possible with one CPFlash?

Setup 1: Rembrandt lighting

Our first setup uses a nice standard lighting technique.

Rembrandt lighting is one of the most common portrait styles and is created using the main light source around 45–60° to one side of the subject and slightly above, so that the near side of the face is fully illuminated while the far side falls mostly into shadow, except for a small patch of light under the eye. 

It’s possible to do this with just a bare CPFlash, which is quite a small and hard light source, to produce a dramatic look. But a larger, softer light source is usually more forgiving and gives a more subtle effect. A bigger light may also be less dazzling for your model.

Here I decided to use a 26″ (65cm) Glow Hexapop softbox, which is an extremely easy to use, lightweight modifier that opens up in seconds. I use its included Bowens S-type adapter with a Godox S-bracket to mount the CPFlash. A nice thing about this tool is that it is all-in-one: the front diffuser panel is stitched in place, so you don’t have to detach and reattach it between shoots. It’s large enough to give a soft light for portraits, but still quite portable. That said, the Hexapop is relatively expensive. You can get similar results with a simple brolly, a diffuser panel or a white bedsheet, though these options are all less efficient, as they ‘spill’ much of the light away from the subject.

Innovatronix CPFlash and iPhone XS one-light setup

Here is the setup. The grey card is standing in for my subject, which in this case is me, since current restrictions limit my shooting to self-portraits (or family members) for now. The softbox is at a height of around two metres (6 feet) — for a standing portraits you might want the light a bit higher than this, but it was hitting my ceiling here. The iPhone XS is mounted on a tripod and using the Adobe Lightroom app. The backdrop is a generic pop-up blue/greenscreen that I got on eBay.

Innovatronix CPFlash and iPhone XS one-light setup

The iPhone XS portrait lens has a fixed aperture of f/2.4. The default camera app doesn’t support manual controls, so I used the Adobe Lightroom app, which has a ‘pro’ camera mode built in. From this I selected the lowest possible sensitivity of Iso-25, for maximum image quality, and a shutter speed of 1/80 second. The CPFlash was set to about 20% (1/5) of full power. The combination of LED flash, the Glow softbox and my low ceiling offered a fairly random colour temperature, so I set a custom white balance using the grey card (see above) as a reference. The setup shot was actually taken using my other phone, but if the iPhone is your daily driver then you could switch to its wideangle lens for this.

The Innovatronix CPFlash lets you use any camera app you like: the shutter and flash are triggered indirectly, either using a shortcut button in your phone’s notifications bar, or via the CPFlash Bluetooth remote. To adjust the power levels of either flash or continuous lamp you use the CPFlash app, which is nearly identical on iOS and Android. The only noticeable difference using the CPFlash on iOS versus Android is that Android provides a floating shutter button on your screen, whereas iOS uses a notification. On both systems I prefer using the Bluetooth remote, which offers more tactile feedback and means I can shoot self-portraits without a self-timer. One button on the remote will simultaneously trip the phone shutter and fire the CPFlash. A second button turns the continuous lamp on and off, if you want to use it for modelling, focussing or video shooting.

Innovatronix CPFlash remote

Here is the resulting (self) portrait, which was shot in DNG format.

Innovatronix CPFlash and iPhone XS one-light portrait

The first thing you might notice is the background looks grey, not blue. This is thanks to the powerful editing capabilities in Lightroom for iOS: I desaturated the blue channel in the colour mixer. Other global adjustments were done on the phone, too: curves, detail and noise reduction. The free version of Lightroom doesn’t let you do local edits, so I later exported the image into Gimp on my computer to edit out creases in the backdrop. (Even at f/2.4, a phone camera has oodles of depth of field, so you can’t blur out background details easily without post processing.) If you are an Adobe Creative Cloud subscriber then I think you can synchronise the image directly to Photoshop to do the same. While it’s remarkably easy and convenient post-processing a photograph on the same phone that was used to shoot it, it’s still nice to review and make more precise edits with a larger screen.

As the nose shadow doesn’t quite join up with the cheek shadow, this particular shot might only be called ‘Rembrandt-ish’, but you get the basic idea. All done with an iPhone, an Innovatronix CPFlash and a small softbox on a light stand. New profile picture, perhaps?

Setup 2: low key

Our second setup will be a ‘low-key’, in that the photograph will be dominated by dark tones and we will aim for a pure black background.

The Glow Hexapop softbox we’ve been using is a great tool, but it has one major weakness: there is no way to attach a grid. When fitted, a grid narrows the beam of light from a softbox, so it just illuminates subjects directly in front of it rather than filling the entire room. In the first setup, a fair amount of light from the softbox was falling on the backdrop. I was actually able to tame this a little bit in the final edit by turning down the luminosity of the blue channel, but you won’t always have this luxury. There is also an element of satisfaction to be had from getting a shot exactly the way you want it ‘in camera’ rather than relying on postprocessing.

I switched out the Glow Hexapop for a square 90×90cm (35×35″) umbrella softbox by Godox. This modifier is a much bigger light source, which would normally make it more difficult to control spill on the background, but it comes with a fabric grid that actually makes it very easy. Simply by angling the softbox slightly away from the background, the grid prevents any light from falling on my blue backdrop, and at the same time stops light from flaring into the iPhone’s camera lens.

This softbox is also very easy to set up; it has an umbrella-type folding mechanism and is based on the Westcott Apollo, so the light stand pokes through a zip-up hole in the bottom of the softbox. Because it works just like an umbrella, you can use it with any kind of light, including the Innovatronix CPFlash, with any standard swivel bracket. However, it has a limited range of tilting, and to access the light inside (for instance, to switch it off or change the batteries) you need to stick your arm inside the softbox. Fortunately, the CPFlash’s built-in Bluetooth means power adjustments can be made directly from your phone. If you don’t have a grid (for instance, if using an umbrella or DIY modifier) you can still ‘flag’ (block) light from hitting the background using a sheet of opaque fabric or cardboard, though this gets harder in small rooms as light will bounce off the walls and ceiling.

Here is the setup. The softbox is on the left of the subject again, but slightly lower (if only because of my ceiling) and pointed slightly away from the background towards the camera position. The backdrop and iPhone are both in the same positions as in setup 1, and once again we have a grey card standing in for the model.

Innovatronix CPFlash and iPhone XS one-light portrait

And the result, which required far less postprocessing than setup 1. In fact, I think this might be the image straight out of the iPhone (after converting to JPEG). This is called short lighting, where the subject’s cheek that is farther from the camera is illuminated, while the cheek nearer the camera is in shadow. As well as making the model’s face appear thinner, the high contrast looks quite dramatic.

Innovatronix CPFlash and iPhone XS one-light portrait

I look rather like I am emerging from the darkness while the back of my head disappears into the background. This might be the look we want, in which case we might stop here. But sometimes it is desirable to separate the subject from the black background. How is this possible with just one light? By adding a reflector to throw some light back on the shadow side of my head. Here I used the silver side of a generic 5-in-1 pop-up reflector. These are widely available, but you could also use a bedsheet, some aluminium foil or just position your subject near a white wall. Here is the same setup with the silver reflector added (hanging from a light stand by a small microphone clamp).

Innovatronix CPFlash and iPhone XS one-light portrait

The result? Now the subject’s full outline is visible, despite wearing black clothes against a black background.

Innovatronix CPFlash and iPhone XS one-light portrait

My father kindly volunteered to model for the same setup. He is taller than I am, but the large softbox and reflector were quite forgiving, so I did not have to reposition everything (as I might had had to do with a small, hard lighting setup).

Innovatronix CPFlash and iPhone XS one-light portrait

Notice the reflection of the softbox grid in his spectacles. Depending on the intended use of the photo, this might be distracting but we thought it looked pretty cool, here. You could remove the reflection by tilting the specs slightly, wearing lens-less empty frames, or editing it out in post. His jumper is more of a matte black than my jacket, so the outline disappears into the background. It might be possible to bring it back by adjusting the position of the reflector, but the greater control would be available by adding a second light source.

These low key shots had very minimal edits applied; I think the only thing I did was clone out a few bits of fluff and stray hairs on each of the photos.

Not bad for a phone camera!

Setup 3: high key

Now for something completely different. Many photographers aspire to create images with a clean white background. This is challenging with multiple lights but we are going to attempt it with just one flash and an iPhone.

The setup is actually very simple. We take our large softbox, remove the grid, and the front of the softbox as the backdrop of the photo. You might be able to achieve the same using a DIY modifier such as a white bedsheet, but this setup pushes the small flash to its limits—we set the CPFlash to fire at full power—so the efficiency of a softbox is beneficial.

Just shooting into a light source like this will give a backlit silhouette. To throw some light back onto the front of your subject, bring out a reflector. Here I used a silver side of a 5-in-1 reflector, but you could use a white piece of foamboard, aluminium foil, or whatever is available to hand. In my case, my reflector is actually a bit too big for this, and made it quite difficult to get the right orientation and position without blocking the iPhone lens. An ideal accessory you can buy is a reflector with a hole in the middle of it so you can poke the lens through and have a frontal fill light without blocking the camera. Or you can have multiple small reflectors positioned around the camera.

Innovatronix CPFlash and iPhone XS one-light portrait

Here is the resulting shot. I won’t pretend this is super easy to pull off: it is difficult to get the reflector in exactly the right place and angle to reflect the light onto the desired part of the subject. In my case the light is maybe a bit lower than I might have liked. But it’s certainly usable, if perhaps not ‘high-key’ (there are clearly dark shadows), it’s a white T-shirt on a clean white background. A bit of editing in Lightroom was needed to get the contrast right, as the iPhone doesn’t really know how to deal with a backlit situation like this.

Innovatronix CPFlash and iPhone XS one-light portrait

Here is another take on the same basic setup. The reflector was moved to just behind the camera, for a more frontal fill light. A large sheet of paper was also added for fill on the opposite side of the camera.

Innovatronix CPFlash and iPhone XS one-light portrait

This multi-reflector setup gives a more even illumination. You can keep experimenting with large and small reflectors, flags and DIY modifiers to get your desired look. This was after a couple of iterations shooting selfies; if shooting other people you’ll have a real-time preview (thanks to the modelling lamp) and be able to make quick refinements.

Innovatronix CPFlash and iPhone XS one-light portrait

With judicious positioning and use of reflectors, we can make one light do the work of multiple. Coupled with a phone with a high-quality telephoto lens and powerful editing software, there’s no reason why you can’t take a range of professional-looking portraits with a smartphone.

This was made possible with the Innovatronix CPFlash, one of the only flashes that works with iPhone and Android phone cameras. It’s currently $199, available directly from the manufacturer. Visit the Innovatronix web site for more information.

Thanks to Innovatronix for sponsoring this article and for providing the iPhone XS and CPFlash for the demonstration.

David Selby
David is a keen photographer and has been editor of Lighting Rumours since 2010. When not writing about lighting, he works as a data scientist at the University of Manchester, UK.