Getting into flashes

[Ryguyinlj]

Hi. I have been involved in surf and skimboarding photography for some time now, and I wanted to try my hand at some other aspects of the art, and I have some questions:

I am wondering, what is the standard way to measure the strength of a flash, or is there a way?

Does the digital rebel (or its 35mm counterpart) suppport an external flash synch?

[another view]

The standard is guide number (or GN). This is measured at full power, of course - but most of the time a flash goes off in one of the auto modes it's at much less than full power. The bigger hot-shoe mounted flashes are in the 100-125 range which isn't that much light if you're trying to cover a distance. Use faster film (like 400) and the two stops you gain will improve the distance you can cover with your flash.

Distance with outdoor fill flash is one of those times when you need a fast shutter sync speed. Flash exposure is covered by aperture and not shutter speed, so the bigger the aperture the farther the distance you can get (because of more exposure). With that wider aperture you'll need a faster shutter speed to compensate or you'll overexpose the ambient light. In practice, the 1/250 on a lot of pro cameras isn't even that great but it's much better than 1/60 on others.

[Speed]

The standard is guide number (or GN). This is measured at full power, of course - but most of the time a flash goes off in one of the auto modes it's at much less than full power. The bigger hot-shoe mounted flashes are in the 100-125 range which isn't that much light if you're trying to cover a distance. Use faster film (like 400) and the two stops you gain will improve the distance you can cover with your flash.

Distance with outdoor fill flash is one of those times when you need a fast shutter sync speed. Flash exposure is covered by aperture and not shutter speed, so the bigger the aperture the farther the distance you can get (because of more exposure). With that wider aperture you'll need a faster shutter speed to compensate or you'll overexpose the ambient light. In practice, the 1/250 on a lot of pro cameras isn't even that great but it's much better than 1/60 on others.

As usual. :-)

I just want to add my two cents worth. You can buy devices to extend your flash distance. They are fresnel lenses, and they attach to your flash. Better Beamer is probably the best known, but there are others out there.

Also, be sure to buy the best (read most powerful) flash you can afford. Like Another View said, most of the time the flash fires at less than full power. But when you need full power, the more the better.

[opus]

I have a Digital Rebel, and bought one for my dad as a present. He is much more knowledgeable than I am about flash, and lately each time we talk, he tells me that if I'm going to buy a flash for my camera, I should get the 580 EX.

That's the sum of my knowledge about flash at this point. "Buy the 580."

[Ryguyinlj]

I am a poor college student (yes, it was hard for me to buy a digital rebel) and I am also curious, which flashes in the speedlite series are more powerful than the built in flash? I am considering a speedlite 220 because I can get it really cheap on ebay, but I dont want to get it if its not a good improvement, for obvious reasons.

[MJS]

I can't speak for the Canon guys, but I will tell you that every time one of my students buys a smaller flash, it is soon left in the bag for the bigger one they wish they had bought in the first place.

Hey Speed, how does one become a Nikon Samurai? I've been shooting one or another since '80.

Michael