Flash Diffuser Design

At our February 2017 meeting, we had a workshop on flash technique and the effectiveness of using flash diffusers, particularly when taking portrait photographs.

In the second part of the evening, we worked on some designs for home made diffusers for pop-up flash and for flashguns. These are the designs and instructions.

Design for Flash Diffusers

As we all know, flash guns can be invaluable when trying to take images in low light conditions or when we need to control the light hitting the subject we are trying to capture. However, one of the major downsides of flash guns is that the light they emit acts like water coming out of a hosepipe. The light is very directional and can create areas of very harsh lighting and areas of very dark shadows.

In most cases, this isn’t the effect we want and, particularly when photographing people, it can be extremely unflattering. The small ‘pop-up’ flash fitted to most SLR camera’s are the worst, simply because the size of the flash is so small and it’s fixed, usually to the same plane as the lens so the ‘hosepipe’ effect is exaggerated.

Whilst with detachable flashguns, this can sometimes be fixed by bouncing the flash off a convenient wall or ceiling, it won’t help if you are in a large space, outdoors or the walls are a very dark or distinctive colour.

However, for pop-up flash, bouncing the light isn’t an option.

So the only way to correct this problem is to use a diffuser or light box. Unless you are into using flash a lot, it probably isn’t worth investing in a diffuser or light box when it is relatively easy to make your own at very little cost. So, here are some designs for you to make a simple clip on diffuser for your pop-up flash, and a simple little light box for you detachable flash.

Pop-Up Flash Diffuser

This diffuser is made out of a plastic bottle. A water, squash or pop bottle will do, provided it is clear plastic. Mark and cut the centre section of the bottle to make a tube or barrel shape. Make sure that the length of the tube is at least three times the width of your pop-up flash head.

Mark around the centre of the tube, then cut a horizontal slot, letter box shape, with the width of the  slot equal to the width of the flash head and the depth equal to the depth of the flash head.

Cover about 1/3rd of the inside circumference of the tube with silver foil. This should be centred on the slot you have cut and is to act as a reflector around the flash head.

Then cover the outside of the tube with greaseproof paper or whatever material you want to use to diffuse the light.

Finally, use some sticky tape over the ends of the tube and the edges of the slot you have cut. This is just to protect the flash from getting scratched by any sharp plastic edges.

Push the tube onto the flash head and away you go!


Flashgun Light Box

The design of this light box is similar to a number of commercially available light boxes but can be  made from cardboard from a cereal box or card of a similar thickness/weight. Whilst this limits the size of box that can be made, it is quite useful for lots of work, including portrait and table top photography.

Cut out two of each of the shapes below out of the cardboard. Cut along the solid lines, the dotted lines are fold lines. Please note that the image is not to scale. The bottom section of the shapes will form a rectangular section tube which will slide over the flashgun. The dimensions shown are for my Nissin flashgun, so may need to be adjusted to fit your particular flashgun.

Once the sections are cut out, glue silver baking foil to the triangular shapes on the sides that will form the inside of the box.

Then, use the 1cm strips down the sides of the main section to glue or tape the sections together. I found it easiest to use some elastic bands to hold the four sections together on the flashgun and then glue the main sections together.

You may find it useful to strengthen the joints using tape.

Finally, cut a rectangle of greaseproof paper (or whatever material you are using for the diffuser) and tape or glue this to the end section.

Finally, take some pics!