When you take a picture of an object, your camera is actually capturing the light that bounces off of that object from whatever light source you happen to have handy. Regardless of the camera you are using and the subject of your photo, when you have great light, you can wind up with great pictures. However, if you have poor light even the best photographer will wind up with poor results.
So, what is great light? Well, it really depends on what you are trying to do. Do you want sharp shadows? Do you want strong contrast? Do you want your colors to be vibrant or subdued? Do you want light to be stronger on one part of your subject and weaker on another? Do you want to bounce a blue light off a red object to make it look purple? The variation of light sources and their resulting effects is nearly infinite, but there are 2 main types of light that I look for and use as a photographer:
- Hard Light: I call it this because it casts hard shadows. This is produced by lights with a very small relative surface area such as a bare light bulb, a camera's built in flash, or the sun.
- Soft Light: So named because it casts very soft shadows and provides very even light. This is produced by lights with a very large surface area such as an overcast sky, a picture window in a living room, or the popular “softbox” studio lights.
Now, to produce really flattering images of people (or pets, or products, or whatever you want to shoot) you generally need VERY soft light… not necessarily dim – but SOFT. This means you need your light to come from as large a surface area as possible. The flash on your camera is not large at all. In fact, on most SLR cameras it is only about a square centimeter or so. Using this flash as your main source of light is a great way to shoot horrible pictures.
A “SpeedLite” or detachable larger flash for your SLR camera will provide better results, but shooting it directly at your subject will still produce unflattering lighting similar to the pop-up flash. If you have a lightly colored wall or low white ceiling available, bouncing your flash off them can produce much better results because the whole wall winds up acting as your light source. But what do you do if there are no great options for bouncing? Well, you'll need a diffuser.
A diffuser accomplishes 2 different goals: Spreading the light and making the light source surface area larger. When looking for a diffuser for my flash, I quickly found a popular diffuser and was impressed with the quality of the photos it produced – and decided to buy one.
Then I looked in my wallet. Not to mention the fact that flash diffusers often cost $60 and accomplish something that a peice of tupperware can do just as well.
Now, let's be honest: the diffuser I was considering is not all that expensive. But if you are at all like me, you'll try to come up with something similar for much cheaper. After a brief poking around on Google to see if others had also tried, I decided to see if I could come up with something similar…so I started with a visit to my local home improvement store: Lowes.
I picked up 2 items at a total cost of $14.21. The items are pictured below:
Drawer liner and velcro. Nothing else to buy.
I wanted the diffuser to be wide enough that it would be able to wrap completely around the base of my flash. I started doing some actual math to figure out the total length of all the sides, then deciding how much overlap I'd need at the base, etc – then chucked out all that and totally guesstimating, I measured 5 inches off the end of the roll and cut it carefully with a sharp pair of scissors:
Aim for about twice the width of your flash and you'll be fine.
After I cut off the piece of drawer liner I slapped some velcro on the ends and that was that. I attached it to my flash and started running around the house taking test shots and muttering to myself about the results. A quick word about the velcro: There are 2 sides to this drawer liner – a very smooth side and a very bumpy side. When folded over in the middle over the top of your flash and then wrapped around the base, the smooth side will face the bumpy side. You want to put one piece of velcro on the smooth side and one on the bumpy, or else they won't attach to each other when folded over your flash. That's the only hard part about building this thing – get that right and you'll be all set:
My DIY flash diffuser mounted to my flash. Notice what a larger surface area it provides?
So, want to see some results? Before we jump into that (unless you just skipped ahead… ) I should say this: This diffuser (and any diffuser) will not instantly make your photos look fantastic. This will merely manipulate your light in new ways. For me, the results were unexpectedly good in some instances, but unexpectedly bad in others. You'll have to get used to when it is right to use a diffuser to get the most out of it.
Here are the first comparison shots I took with the diffuser off and on:
The bounce flash shot was done by pointing the flash up at the ceiling and allowing the light to bounce onto the subject. The DIY diffuser shot has much more vibrant colors, but has harder light (you can tell because the shadows have sharper edges). CLICK PHOTO TO ENLARGE
With this set there are a few surprises : I was surprised to see the sharper shadows in the second image above, but now understand (after shooting a bunch more comparisons) what is going on here. The flash was pointed up at the ceiling as in the first image, but the light was being bounced around and redirected out the front face of the diffuser as well. Effectively, this produces 2 light sources: There will still be plenty of light hitting the ceiling and bouncing back, but there will *also* be plenty of light forced out the front of the diffuser directly at your subject. This is important to understand, as it can produce some very unexpected results.
Here is another comparison:
This is a good example of where a lighting diffuser is NOT the best option. Here the picture using bounce flash is much better because it casts an interesting soft shadow on the fruit. The flash for the bounce shot was bounced off of a side wall. You can also see that the light picked up a bit of the color of the side wall.
These 2 images above illustrate how using a diffuser can be the wrong choice sometimes. In the bottom image, we are getting too much light directly diffused off the flash towards our subject, and losing the great texture and depth of shadow that the first shot captures so well. Also note the much cooler tone of the image with the diffused flash.
Now for an example that uses the above effect for better results than a typical bounce flash:
In this example, you can see that the diffuser did better job than the bounce flash.
The differences between these 2 shots are very subtle, but come down to using the right combination of the light bouncing off the ceiling and the light coming out the face of the diffuser. In the top picture, the colors are subdued slightly and flatter. In the second picture the highlights on the petals (especially the lily and the Alstroemeria) are much more pronounced. These highlights were brought out by the light emitted from the face of the diffuser, and make the difference between the somewhat flat first image and more vibrant second image.
At this point you may be asking: “What about portraits? I heard that diffusers were great for portraits!” Here are a few shots of my wife to illustrate how the diffuser affects portraiture:
No diffuser. Flash aimed directly at subject using ETTL
Flash with diffuser attached. Flash aimed at the ceiling.
There are are some substantial differences in these shots. The second has great highlights and much more evenly lit hair. You can see the texture of her sweater, and her face is much more evenly lit with softer shadows.
The final comparison is of 4 types of flash: built-in pop-up, SpeedLite aimed at subject, SpeedLite bounced off the wall, SpeedLite with diffuser bounced off the wall:
Now I can see what all the fuss is about with diffusers! This last shot is leaps and bounds better than the first with just the built-in flash, and is noticeably better than the best I was able to do in this setting with a bounce off the wall. I'm thoroughly convinced that my $14.21 was money very well spent!