Diffusing pop-up flash

The main problem with cameras that have either pop-up flash or built-in flash is that the flash can make your pictures look totally washed out with hard shadows everywhere. Flash is usually bluish white in color but can also pick up other colors from surrounding surfaces such as walls and ceilings.

You can minimize these problems by doing one or more of the following:

1. diffuse the flash and make it less harsh with a translucent material such as clear plastic.

2. reduce flash power by adjusting flash compensation (look for a button with a lightning bolt symbol).

3. reduce flash distance with a wider aperture and a lower ISO value, i.e. f/2.8 at ISO 200

4. increase ambient light with a slower shutter speed and a higher ISO value, i.e. 1/30 at ISO 400

I chose option #1 above and decided to create my own custom flash diffuser. First, I wanted to bounce light over my subject to create a nice contrasting image.  Next, I wanted to soften any hard shadows with fill-light. Light quality is usually base on the size of your light source. The bigger the light source is, the more it will become diffused (and brighter) as you get closer to it.

I took the diffuser dome from my SB700 Speedlight and proceeded to create a bounce card and a reflector all-in-one thing. The bounce card will help bounce some of the flash upwards while the reflector will enable me to use fill-flash.  Why the reflector? When the flash goes off, some of the light inside the diffuser dome is deflected off the plastic material and ends up back in your face. The nifty little reflector will force the diffused light back towards your subject and all around the room.

Since the weight of the diffuser is now much heavier than before, I had used a velcro strap to secure the diffuser all-in-one thing to the camera's flash head.

Back image of the diffuser dome attached to the camera with a velcro strap. The velcro strap also holds up the flash head from being weight down.

Front image of the diffuser dome that had come from my SB700 Speedlight. You can use any clear plastic container if you have one.

The bounce card (just below the flash head) and the reflector (behind the flash head) can be seen here with the diffuser dome removed. Foil tape was used since it is more durable than aluminum foil.

Side image of the bounce card which will help us deflect some of the flash upwards.

With the diffuser dome removed, we can see that the bounced flash has overexposed the upper half of the room. The lower half remains in the shadows since the flash itself is being partially blocked by the bounce card. Notice the hard shadows behind the chandelier and flowers.

f/5.6, 1/60, ISO 400, matrix metering, +1 FC 

I placed the diffuser dome back on the camera and took another shot. The overall light has dramatically fallen off but we no longer have the dreaded shadow in the lower half of the room as before. It gets more brighter as we get closer to the light source since thats where the flash is. The hard shadows are actually much softer too.

f/5.6, 1/60, ISO 400, matrix metering, +1 FC

Final image with the room lights on to give the picture a nice warm fuzzy feeling.

f/5.6, 1/60, ISO 400, matrix metering, +1 FC

Zooming in on the flower, you can see that there is visible light from the bounced flash.

f/5.6, 1/60, ISO 400, matrix metering, +1 FC

 Thanks for reading.  For my next article, I will get creative using a single Speedlight.

The views and opinions expressed in this article are those of the author and do not necessarily reflect the views and opinions held by dpreview.com or any affiliated companies.

Comments

_sem_
By _sem_ (Jul 15, 2012)

Here's my diffuser variant:
http://forums.dpreview.com/forums/readflat.asp?forum=1034&message=35026936
Notice that he shadows-softening effect of the slightly larger diffuser, compared to the cut ping-pong ball, is only noticeable at /very/ close range. And, the small diffuser doesn't really soften the shadows, merely fills them in with the reflections from walls/celiling, while its direct contribution still has a sharp-edged shadow (only with less contrast).

Mind the default TTL-BL mode is likely to underexpose more than 1EV when attempting to diffuse or bounce the pop-up flash. So you are likely to get underexposure but with not all flash power used. However, with flash on manual full power, bouncing with a ladies mirror from a low white ceiling, with a kit zoom @18mm F/3.5, ISO 200, the little flash of the D90 may expose ok up to 5m distance.
Other workarounds are turning metering to spot or using FV-lock, which both change the flash mode to something more like plain TTL.

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