A Flash Worth The Money

This just in from the world of retail: The more you pay, the more you get. I did some test shots with different flashes to see if I  could get results that were easily displayed and explained. I used my Canon EOS Rebel XTi, which is now a rather out of date 10mp DSLR that's still a damn good light weight, easy to use camera.

 

I know several photographers who'll tell you never to use the pop-up flash on such a camera. To them I say "Never say never." Ignore the low resolution of this picture. The point is the flash exposure. It's not bad with the sync set to 1st curtain.

The sync setting tells the flash to fire at the instant the shutter opens (1st curtain) or the instant before it closes (2nd curtain). In some situations the 2nd curtain allows for the exposure of background or other non-central elements before the flash exposes the central element of the picture. Here's the same shot with the sync changed to 2nd curtain.

 

Do you see the difference? Me neither. With the camera holding the exposure settings at 1/60 sec. at f 4.0 the exposures look identical. In a moment I'll show you how 2nd curtain sync can really be made to work for you.  So far we've seen that the pop-up flash can produce an acceptable photograph with the camera doing the exposure settings.

Here's a shot with an add-on flash, a small Sunpak that's not reading the camera settings. 

It's not a bad exposure but you'll notice that the background is not as exposed as in the shots made with the pop-up flash. The sky was pretty consistently overcast so I don't think cloud cover was variable. I tried a couple more using the Sunpak and adjusting the exposure settings in manual. I used a scale printed on the back of the flash but ...

 

Never mind. I got nothing that was more pleasing than the shots with the pop-up flash. 

Then I brought out one of my favorite accessories. The Canon Speedlite 580EX 2. This flash reads the camera settings and adjusts the flash output accordingly. Canon calls this flash an E-TTL 2 flash. TTL generally refers to Through The Lens metering and this is a second genertion of Canon's E-TTL flashes. 

 

The flash uses an infrared beam from the flash body to take a reading off the subject and adjust itself to the cameras exposure settings. In the above shot I'm exposed nicely but the background is a little dingy. With that in mind I adjusted the cameras exposure settings.

 

The flash maintained its output according to the infrared reading off my body but the wider aperture lit up the background some. Here's one more with another change to the camera settings to get more of the background.

 

Here the slower shutter lights up the background even more while the dedicated flash just keeps the output set for me. Remember that the sync was set to 2nd curtain. Check your owners manual for your camera's sync settings. They're usually in the custom functions but I don't see a reason not to leave the camera on 2nd curtain sync all the time.

I think this shows the value of using what's called a dedicated flash unit, one whose electronics talk to your camera. The flash unit maintained the correct output for me even as the camera's exposure settings were letting in more and more light. Even with that great technology it took several tries to get an exposure that I liked.

BTW; if you're thinking that the first exposure using the pop-up flash is still the best, we're in disagreement but it is a matter of taste. I think the last exposure taken with the Speedlite 580EX 2 is much more pleasing but you can see here that you have many options.

Returning to my opening cliche, the cheapest option here is to just use the pop-up flash and spend no more on an external flash. Your 2nd option would be to purchase a relatively inexpensive flash that's not dedicated and probably find your self doing more adjusting and taking more trial-and-error shots to get a good exposure. Your 3rd option is the most expensive; to purchase a high quality flash that's dedicated to your camera and makes getting great exposures much more likely. 

Note that the 580EX 2 was made to communicate with cameras produced after the Canon EOS Rebel XTi was made but it still used the basic information transmitted from the camera. When I slide it in to the shoe on my Canon EOS 5D Mk 2 it works almost effortlessly and it has many options built in so I can get all manual and experimental as I often do. You can find earlier EX flash models (or the counterparts for your camera) at some retailers and some outlets like e-bay or Amazon and you'll get many of the benefits of TTL flashes and save some bucks.

On Monday: how to evaluate your f stops