Build your own macro ring-light

English Version 0.2 Final, November 2002

Introduction

This is a tutorial on making a so-called macro ring-light and is intended for people who own a consumer type of digital camera with macro capabilities. You don't have to take your camera apart for this.

• Where to use it for
• Materials and tools
• About LED's
• Voltages
• Power
• Results & examples

Where to use it for

I got the idea of building a ring-light when I saw the announcement of the new Nikon Cool-light SL-1. Nikon's ring-light is simply a lens adapter with 8 white LED's on the sides, nothing special.

A ring-light can be useful when photographing from really close by (macro). When holding your camera close to the subject you are likely to block the light coming from another light source. Using the flash won't do much good either. It's positioned above the lens, the lens barrel will probably block it, otherwise it would overexpose the scene because it will be too bright.

There are some macro flashes around, but they're very expensive and intended for SLR camera's not the consumer typed digital camera. Because the light comes from different angles the light is equally divided and the scene is perfectly lit.

Except for macro shots the ring-light can be useful in a variety of situations. Some cameras have trouble focussing in dark areas's. Within approximately 10 feet (3 meters) the ring-light can help the camera focus. You can use flash to light the scene. A flash only lasts a fraction of a second, the ring-light constantly emits light. This feature is particularly useful when recording movies in dark places.

It doubles as a red-eye reduction. When taking pictures of people with flash their eyes will sometimes be red. This is caused by the light from the flash bouncing back from the retina inside the eye. any cameras have a built in red-eye reduction, the flash will fire a few times before taking the picture. The light from the previous flashes will make the eyes adapt, the pupils will shrink. However, because of the flashes that are fired first there will be quite a delay between pressing the shutter and the actual photo being taken. Sometimes missing the moment you wanted to capture. A ring-light will also solve this problem.

Unfortunately ring-lights are very pricey. It's even harder to find one that fits' your camera, if it exists. That's why I decided to build one myself. The biggest issue was how to attach it to the lens. I considered clamming something around the lens barrel or doing something with the tripod mount. Maybe these solutions will work for you.

Materials and tools

Materials

• Camera with threaded lens.
• Filter, something that can be screwed into the thread
• A piece of approximately 4² inch (10² centimeters) thin plastic.
• 6 to 12 white LED's
• At least 15 inch (40 centimeters) isolated copper wire
• Power source that can provide 3 to 4.5 volts (DC).

Notice: Because artificial light is colored yellow the white LED's look blue on some pictures because the white balance wasn't set properly.

Tools

• Pencil
• Pair of compasses
• Something to measure degrees
• Soldering iron
• Sandpaper
• Tool to strip the isolation from wires
• Scissors - something to cut the wires with
• Drawing pin
• Drill

About LED's

We use white LED's simply because the light needs to be white. This is very important for the accurate reproduction of colors in the picture. There are two different sizes available. 3 and 5 millimeter (diameter). We use the largest ones because they shine the brightest. The ones that I used are meant for 3.5 volts but also work fine on 3 volts. LED's will only work when their properly connected, this is usually done by connecting the + to the long leg and the - to the short leg. Doing the opposite won't do any harm, it won't work though.

Voltages

If you want to be mobile you will probably use batteries to power the LED's. It doesn't really matter which kind you use. Penlites and such have a voltage of 1.5 volts, rechargeable ones 1.2 volts. White LED's are available in both 3.5 and 4.0 volts (ask the salesman). They will work with less, but won't be as bright as they can get. You could use a higher voltage but that wouldn't be very good for their life span. This is a list of how you can get the proper voltage for your LED's. A simple resistor should be placed between the battery and LED's when the voltage is too high. You can buy them in any electronics store for a few cents.

Voltage Needed	Power Source	Resistor needed
3.5	3.0 (2 x 1.5)
3.5	4.5 (3 x 1.5)	8 Ohm
3.5	3.6 (3 x 1.2)
4.0	4.5 (3 x 1.5)	4 Ohm
4.0	3.6 (3 x 1.2)

The material I used to hold it all together was a plastic white layer. It's stiff but still flexible. I also heard of people successfully using a beermat. An 8 centimeter CD would probably also work. It's important to take a neutral colored surface like white, grey or black a reflective surface would be the best because it reflects the most light. LED's shine brightest in front though.

The piece I used was only 4² inch (10² centimeters) large. My camera's lens has a diameter of 35.5 millimeter, so the first circle was 35.5 millimeter. I used a pair of compasses with a sharp ends that could cut out the inner circle just by rotating it a few times it. The outer circle was 80 millimeter wide. I used a pair of scissors to cut it out.

I used some sandpaper to shave of the sharp edges on both the inside and the outside.

because I bought 6 LED's for € 2.50 each I had to put a space 60 degrees in between them (360 divided into 6 is 60). I put a line there and made a small hole with the compasses on the place where I wanted to drill the holes. The hole we're drilling must be just as large as the LED's, 5 millimeter in this case. Again I used sandpaper to smooth the edges. You can now put the LED's through the holes.

Now you only have to connect the LED's with each other. They all have to be connected in the same way. The positive (+) on the long leg and the negative (-) on the short leg.

Do not connect the in the serial way, they would need somewhere between 18 and 24 volts to work! You have to connect them parallel, that means they all need a direct connection with the power source. The image above shows how I did that.

The wire's isolation is stripped every 3 centimeter (1.2 inch), the copper wire is exposed and makes contact to the LED's legs. I stuck a drawing pin on my desk and used that to make a noose in the copper wires where the LED's legs can be put through.

The noose in the copper wire.

After connecting the wires the macro ring-light should work. The finishing touch is to solder the wires to the legs and cut the rest off.

The macro ring-light can be attached to the camera by putting the screwing the filter on the lens with the light between it. If the filter doesn't fit through the hole in the macro ring-light use sandpaper to make the hole a bit wider.

Attach the ring between the lens and filter.

Power

This part of the tutorial is not necessarily but can be used a s a source of inspiration for supplying power.

Materials

• Battery holder
• Double sided sticky tape
• Tripod with detachable shoe
• Piece of hard, thin plastic

Unless you're planning on using it inside, you need a portable battery pack. As said before, I use a battery holder for 2 AA batteries, together they deliver 3 volts. I connected it simply by soldering the two wires to the macro ring-light.

Again I took a layer of thin, hard plastic. After measuring a bit I drilled two holes at the right places. One of 7 millimeter and one of 4 millimeter, I used sandpaper to make it 4.5 millimeter. My tripod fits through these holes.

My tripod's shoe.

If you don't have a tripod with a detachable shoe you can also use something else like a mini tripod or a flash bracket

I cut the plastic a a nice round shape and shaved of the sharp edges with sandpaper.

First I considered glueing the battery holder to he plastic, using double sided sticky tape works even better.

Now we have a mobile batterypack that can be attached underneath the camera.

Results & examples

These pictures show the difference that the macro right-light can make.

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