Camera Flash Advice

John Williams

TPF Noob!
Dec 12, 2007
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I'm looking into getting a flash for my 350d and was wondering what i should be looking out for, what makes an expensive flash better than other less expensive ones, and just general advice on what i should be looking for.

Oh, and are they ok second hand or is there too many things that could be wrong with them(coz i'm not a fan of spending more than i have too ;))?

The more expensive flash units will 'dedicated' to work with your camera. They will communicate with the camera to give you E-TTL metering (Electronic Through The Lens). This means that the flash fires a preflash to meter the reflected light, the camera reads the light and tells the flash how much power to use for the actual flash. This all happens so fast that you can barely tell that the flash fried twice.

The benefit of a system like this is that it will set the flash power to the setting that you want to use. If you want to use F8, it will automatically meter and give you enough power for F8. If you want to use F2.8, the it will adjust for that. To vary the exposure from the flash, you use FEC (flash Exposure Compensation).

The cheaper flash units may not be dedicated. Instead, they might have their own built-in metering. They way these usually work is that they fire and measure the light at the same time, when enough light has reflected back to the flash's quenches the light. These can actually work fairly well...but you have to make sure that you are using the same settings on the flash, as you are on the camera. And if you change the settings...then both need to be re-aligned.

Most flashes can be fired in a 'manual' mode...some only have a manual mode. In this case, you would need to calculate the correct aperture to use, using the flash's Guide Number and the distance to the subject.

There are some build quality issues. The more expensive ones will usually be built better. Also, there is wireless technology. Canon uses IR technology for it's wireless flash. You would need at least two units. One to be a master and one to be a slave. The expensive Canon flash, the 580EX, can be either a master or a slave. The 430EX can only be a slave.

I would recommend the 430EX, if you can afford it.
Great explanation and thanks for taking the time i appreciate it.

I think the 580EX is a bit out of my price range anyway so i'll look into the 430EX further for now.

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