Fill Flash (1 Viewer)

I am fairly new at Bird Photography and recently started using an external flash.

My current setup is a Nikon D40 with a SB400 flash unit. This flash unit is too small for a flash extender like the "Better Beamer" etc. So, I assumed I should alter the flash level to +1 to get a longer reach with the flash.

However, all the articles that I have read suggest you lower the flash level to -1, or more, so that your flash just fills in the shadows and doesn't wash out the bright areas.

One fellow was explaining how he uses his flash extender - which I assume increases the flash on the bird - with a -1.5 flash setting - which I assume reduces the flash on the bird. I would have thought these 2 effects would cancel out.

Have I missed some basic thing or is it just distance? Set the flash for +1 when the bird is farther and to the minus setting when the bird is fairly close?

This will probably be a bit like the blind (Canon user) leading the blind but as no-one else has answered, I'll have a go.

When you use a flash extender you get a higher intensity of light at arriving at the target than the camera expects from the information it gets from the focus distance and light metering. Therefore, in order to use 'fill flash' with an extender, you have to dial in more negative flash exposure compensation than you would normally without the extender.

Have I missed some basic thing or is it just distance? Set the flash for +1 when the bird is farther and to the minus setting when the bird is fairly close?

Click to expand...

This is wrong. The camera works out how much light to put out assuming that yours is a sophisticated flash that ties in with the camera's metering so as long as the bird is within range for the flash you always dial in -1 (and adjust according to experience).

If you search the forums with terms like fill flash you'll probably find a lot more erudite stuff on the subject.

Cheers

Tim

Pretty good Tim

The 'brightness' of flash light is basically determined by power and distance to the subject and a flash has a limited range (i.e. distance). The extender concentrates the light into a tighter beam to extend this range and brightness on closer subjects.

Increasing the flash output by dialling in positive compensation (assuming in an auto fill flash 'mode') can only increase the distance to the flash's maximum output (without an extender).

The extender also means that less power is required to get the same brightness, so faster recycle times on the flash.

As Tim says, dialling in flash compensation with an extender is all about user experience as the camera has no idea the extender is present and works within the capabilities of the attached flash.

Have a look at the Flash photography threads in World Photography Forum for better explinations of how flash does it's thing.

I don't know if you've looked into it, but the beamer comes in different sizes, and you may be lucky with one of the smaller ones such as this one for the Canon 430ex. I first had one for the Canon 580, and could never get it to line up properly on the 430ex, so was very happy to get the smaller one.