Update: Canon Speedlite 600EX vs. Canon Speedlite 580EX II

The purpose of this review is to show the frame coverage of Canon Speedlite 580EX II flash in various applications.

The fist test demonstrates the "direct" frame coverage by shooting an indexed wall, which allows seeing the actual angle of view at the different flash zoom settings. The flash must cover at least the area corresponding to the set zoom value.

External flashes are often used for bouncing the light off of walls and ceilings. That is often done while also using a built-in white card (catchlight card) or an aftermarket flash reflector (such as Demb Flip-it!, LumiQuest Quik Bounce, etc.). When a bare flash is pointed toward a ceiling, most of the light is thrown vertically. Some portion of the light, however, �spills� horizontally in all directions. The �spilled� light can be redirected toward the subject (with a built-in white card or other reflectors). The amount of the �spilled� light may vary depending on the flash zoom setting and the side the light �spills� off of.

Thus, the second test shows the frame coverage of the white card built into Canon 580EX II flash. This test is similar to the flash diffuser frame coverage test, where we test various aftermarket flash light modifiers.

The last two tests show the light �spilled� off of a wide and a narrow side of the Canon Speedlite 580EX II flash. This information can be useful for better understanding of the results produced by some of the aftermarket flash reflectors (Demb Flip-it!, DiffuseiT, etc.).

All the tests are done outdoors, at night, with no walls or other reflective surfaces around that can affect the images. All the test images are taken at manual flash power and tweaked in the post processing to have the similar exposure.

Direct flash

14mm, direct flash	24mm, direct flash

28mm, direct flash	35mm, direct flash

50mm, direct flash	70mm, direct flash

80mm, direct flash	105mm, direct flash

White Card

14mm, head vertical, white card	24mm, head vertical, white card

50mm, head vertical, white card	105mm, head vertical, white card

Flash Head Vertical, Wide Side

14mm, head vertical, wide side	24mm, head vertical, wide side

50mm, head vertical, wide side	105mm, head vertical, wide side

Flash Head Vertical, Narrow Side

14mm, head vertical, narrow side	24mm, head vertical, narrow side

50mm, head vertical, narrow side	105mm, head vertical, narrow side

As you can see, Canon Speedlite 580EX II produces even frame illumination for the flash zoom settings of 50mm and higher. The lower zoom values exhibit a noticeable light falloff. For example, the 14mm setting (with the built-in wide angle panel) is obviously quite ambitious. While Canon Speedlite 580EX II does reach the 14mm mark, the light starts to falloff at around 21mm angle of view.

The white card frame coverage differs depending on the flash zoom setting, but not significantly. It is equivalent to about 50mm angle of view.

The light coming off of a narrow side of Canon 580EX II flash is more �centered� than the light "spilling" off of a wide side. (This, of course, is an expected result.) In real life shots, however, that doesn't make much of a difference. The more important difference is that the �narrow side light� is about 1/2 stop more powerful than the �wide side light�. Thus, putting a bounce card or a variable angle reflector on a narrow side of your Canon 580EX II flash gives you more fill light (and a better shooting range) than putting it on a wide side. The two images below illustrate the difference (both images are taken in manual mode with identical power setting).

50mm, head vertical, wide side, full power	50mm, head vertical, narrow side, full power