Zoomlight - a Mini USB-powered Softbox for Video Calls and Streaming

Video calls have become a big part of many of our lives over the last year, and let's face it, we don't always look our best.

Whilst getting a good quality webcam is important (if you can find one!) you'll also want to think about lighting. Ideally you'll want diffuse lighting (that is, spread over a wide area), with a neutral to warm white tint, positioned somewhere just above eye level.

Commercial lighting solutions tend to be quite bulky or expensive - from the classic photographer's softbox to modern LED video lights, and setups intended for streamers (like the Elgato range).

I wanted to create something I could build quickly with a few simple parts. I decided to use the old photographer's trick of a "bounce card", where the light is fired sideways and then diffused towards the viewer using a piece of white cardboard. For the light source I'm using an LED strip, powered from USB (so it plugs into a monitor or laptop), all packaged in a classic Altoids-sized metal tin.

I hope you like it!

This project needs the following parts:

• 12V LED strip. It's worth spending some time choosing the right strip. We want something with the right colour temperature and high CRI (colour rendering index). A strip that is warm white (around 3000K) is ideal because the red end of the spectrum diffuses more readily through skin so helps smooth over wrinkles. Remembering that confusingly higher colour temperature gives you cooler looking colours! A strip with high CRI (90+) makes colours look more realistic. I bought https://www.aliexpress.com/item/4001218891778.html - you only need a short length so 0.5M is fine. Make sure you buy the 12V version! (<$5)
• USB to 12V power supply. There's a few different ways of powering the strip, but this worked well for me: https://www.aliexpress.com/item/4001268877044.html (<$2)
• 2.1mm panel socket. You may already have some of these, if not then these will do https://www.aliexpress.com/item/32997585647.html
• Metal tin. You can use the class Altoids tin, or similar unbranded items are available (e.g. https://thepihut.com/products/altoids-mints-sized-tin. I used the box from a torch I bought a while back. It should be around 59 x 94mm, but the exact size doesn't really matter, as long as it's at least 12mm deep. The metal of the tin helps dissipate the heat generated by the LED strip.
• 3x 100 ohm resistors. Normal USB supplies 5V at 500mA. Scaled up to 12V, we won't get more than 200mA out of the power supply. LED strips can easily draw more than that (and would probably be too bright) so to limit the current we need a few resistors. Exactly what you need will depend on the strip you've chosen and how bright you want the light to be. I measured around 9V drop over the LEDs at 100mA, meaning a drop of 3V over the resistors, and from R=V/I, we get a target of 30 ohms. We need to be a bit careful about power dissipation though - as P=VI, we expect a dissipation of 0.3W, above the maximum 0.25W of basic film resistors. I used three 100 ohm resistors in parallel, to give me around 33 ohms effective resistance with only 0.1W dissipation each. Easy!
• A small piece of white card.
• A short piece of hookup wire.

All told, I reckon the cost should be around $10, depending on where you buy/ship from.

In terms of tools, we only need:

• Soldering iron + solder
• High speed drill (e.g. Dremel) with a bit suitable for drilling into metal

It's also handy to have a multimeter to check your wiring.

First of all, drill a hole in the short side of the tin. Take care not to slip when starting off!

Gradually make the hole larger until the threaded part of the power connector fits through.

Once the hole is big enough, make sure you remove any sharp metal burrs, either with the drill itself or a metal file.

The circuit is very simple - current flows from the positive terminal of the connector through the resistors soldered in parallel, into the strip, then back from the strip to the negative terminal.

I always find I have to use a multimeter to remember which tag of the connector is which, so make sure you check this! The power supply I suggested is "center positive" so we want to connect from that through the resistors to the +12V of the strip.

Twist the terminals of the resistors together to hold them whilst soldering.

Trip the strip to a suitable size to go around three edges of the tin. I trimmed mine to around 23cm.

IMPORTANT! LED lighting strips (unlike WS2812 strips) can only be cut at certain positions along their length. These are marked with a scissors drawing.

I also added a little heatshrink over the resistors to keep things neat.

Trim the white card to fit snugly into the bottom of the case. If it's a bit loose, you can always add a dab of adhesive underneath to hold it in place. In the photos you'll see I did this after adding the circuit, which made life more difficult!

Fit the panel connector through the side of the tin and tightend the nut on the outside.

Then peel of the adhesive backing of the strip, and press it firmly to the side of the tin all the way around. Be a little careful around the corners though - LED strips don't like being bent too tightly so if your tin is particularly square you shouldn't force them.

Once it's all assembled, plug in the power supply and it should light up straight away. If you run into any problems you'll want to use a multimeter to debug.

I attached mine to the top of my monitor with a sticky pad, but blu tack would work just as well. If you wanted to be fancy you might want to try using small magnets. Mounting it onto a laptop might be more of a challenge, so if you have any good ideas please share them in the comments below.

I'm very happy with my build, it was quick and effective, but if I was to make a second version I might add a power switch, as at the moment I need to unplug it from USB to turn it off. Variable brightness would be another nice addition. I found a couple of other unexpected benefits: the side firing LEDs also acts as a desk lamp, and the power supply fits inside the tin so with the lid on the whole thing packs away neatly for transport.

Good luck and happy Zooming!