Fill Flash

Earlier this week Julia, a reader, asked:

"Is there ever a time when you would want to have the flash not bounce?"

This is a great question - especially considering my enthusiasm for bouncing the light from a flash off the ceiling.  There are definitely circumstances in which using direct flash is appropriate.  Here are some examples:

1. When you don't have a flash that can bounce.  This may seem obvious, but I don't just mean if you don't own a flash with the capability to aim up.  There are times our daughters are doing something super cute when the time to capture it is limited.  In these circumstances there may be time to simply grab a camera, pop up the flash and fire, but not enough time to get another flash before the moment is over.  That's what happened here, one of the first times our daughter was laughing at us . . .

Additionally, there are times we are out and about with only our point and shoot camera in a pocket.  If we need a flash, there's only one option.  And it can do a decent job . . .

I mention these circumstances first not because this is a life altering insight, but because I don't want any of you to get so serious about great exposure that you miss out on capturing great moments.  So don't forget that using the flash on your camera might enable you to get a picture you couldn't get without it.

2. I doubt the above advice is exactly what Julia was looking for, so here's an answer for when direct flash is actually better than bouncing the flash.  It's what people commonly refer to as "fill-flash."  The idea is that light from a flash coming at your subject from a horizontal angle can "fill in" shadows created by light coming from above or behind your subject.  In these cases you use your flash to even out the lighting in the scene.  I talked about this some in a post on controlling the power of your flash.  Here are some examples from that post . . .

This shot is taken without using a flash and the background is too bright for the subject.

And here is the same shot using a direct flash.

This technique is also very useful when light from above (often the sun) is casting dark shadows on your subjects eyes.

3. Another time direct flash is preferable is when the ceiling (or whatever you would bounce the light off) is not white (or at least close to white.)  This will cause your image to have a color cast.

Bounce Flash Examples

Here are some examples of what I talked about yesterday:

Direct Flash

Bounce Flash

Direct Flash

Bounce Flash

Introduction to Bounce Flash

• Nikon SB-400
• Canon 270EX

How to Control the Flash

When using an on-camera-flash, we rarely achieve even exposure.  Typically one part of the picture is way too bright, or most of the picture is way too dark.  This is because that little flash doesn't light up the whole scene evenly, but instead gives us a spotlight effect like this:

I love this picture, but not because of it's photographic excellence.

One of the important components that contributes to using your on-camera-flash effectively is understanding how to control its power.  If you know how to do this, you can essentially turn your flash up and down to better balance its brightness with other light sources in your picture.

So here's how on the Nikon D40.  (If you are in green-auto mode, forget about it.  You can't control anything.  Switch to P to control your flash . . . but remember, your flash isn't going to pop up unless you push the button.)  Assuming you have popped up your flash you need to hold down the flash release button and the exposure compensation button while winding the command dial.  I've indicated these controls in order in the following images.

As you wind, you will see a number changing in the view finder and a corresponding number changing on the LCD screen.  As with exposure compensation, you will see a 0 change to things like +.3 , +.7 , +1 . . . or -.3 , .-7 , -1 . . . The negative numbers decrease the flash output and the positive numbers increase it.  Remember to change it back when you are done.

Application
So what's the use?  First we must consider when our on-camera-flash is useful in the first place.  It's always there as a last resort as in the picture above, but its real usefulness comes when a small portion of your image needs more light to even out the exposure.  Here's an example:

Elizabeth's face is too dark for the rest of the picture because she is in the shade and the background is in the sun.  I can't very easily darken the background, but I can use the flash to brighten her face.  So I popped up the flash and got this:

Not exactly what I want, so I employed the technique I just described and dialed the flash power down to -1.  I got this:

And this at -2:

The best option would probably be between these two (maybe -1.3 or -1.7,) but hopefully you get the point.  This example shows both a good example of when your flash is useful and also how to use it effectively.

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