Canon 540ez Question

[NormanRC51]

So my local shop has this flash for $70 used. I am still confused on flashes and trying to learn what all the functions do and are for. Of course the shop is going to say it is a great flash. But what i am wondering is will it work good with my Canon 30D. I am a beginner photographer and this will be my first flash. Thank you for your input.

[inkista]

Ok, a quick rundown of flash features:

Power output: this is usually given by the notoriously not-consistently-measured guide number, but the more power a flash has, the better. This is analogous to maximum aperture on a lens. The more power you have, the more light you have to work with. The 540EZ is decently powered.

e-TTL II: This is the system that Canon uses for the camera and flash to talk together so that the flash power can be automatically set via TTL (through-the-lens) metering by the camera. The camera sends out a preflash of a known brightness, meters it, then set the power on the flash to match what it ought to be. This is analogous to having Av or Tv mode on the camera. In the ballpark, but can be thrown off if the metering is thrown off. The 540EZ cannot do this, it is too old. It speaks the earlier (non-compatible) TTL and A-TTL, not E-TTL I or II.

Manual mode: This is the opposite of e-TTL II. You can explicitly set the power level of the flash to exactly what you want. Like M mode on a camera, it gives you more control and consistency.

PC port: A synch port, where you can externally control the firing of the flash (and only the firing of the flash) either through a sync cable (like an extension cord between your camera and your flash), or a trigger of some kind (optical, radio, etc.) that can connect to the flash. This is a nice-to-have if your triggering system has a PC connector on it, but you can also find triggers that connect directly to the hotshoe. The only problem here is that they all inevitably add to the height of the flash on a light stand.

Remote commanding: as part of the eTTL II system, Canon flashes can signal each other so that you have most of the on-camera flash features with remote flashes. The 7D and 60D pop-up flashes can do the mastering functions, as can an ST-E2, 580EXII, 580EX, and 550EX, with varying degrees of features. The 540EZ cannot do this.

High-speed sync: again, as part of the eTTL-II system, the flash and camera body can syncrhonize light pulses, so that shutter speeds higher than the camera body's max. synch speed (typically 1/200s) can be used. Again, the 540EZ cannot do this.

Tilt & Swivel: the head of a flash can move around so that when bouncing the flash a specific area can be chosen to bounce off. The best flashes can tilt all the way straight up (90&deg with a small amount downwards, and can swivile a full 360°--180° in either direction. Swivel can also be useful with the light-based remote commanding system, as the sensor on the front of the flash has to "see" the master unit's signals. The 540EZ is great on the tilt, but (I'm guessing from the era) only does 180° to the left, and 90° to the right.

Zoom: adjusts the spread of the light output to match the angle of view of the lens. The wider the spread, the smaller the reach of the light. The 540EZ zooms.

Battery packs: as with camera bodies, so with flashes. Sometimes you want more juice than you can get from just the batteries you put in. External battery pack connectors are required to use an external battery pack. The 540EZ has one.

So, yes, you can use a 540EZ on your 30D, but it only works in (the flash) Manual mode, where you will have to dial in the power output you want on the back of the flash for every shot.

[NormanRC51]

Thank you very much for the information on the flash! I very much appreciate it. With reading what you said I think i am going to pass on that 540ez. I will just look for a flash that is "more compatible" with all the settings between the 30D and the flash.

Thanks again for the excellent explanation.