shutter speed on my Canon Rebel

[rodddy]

Can anyone tell me on my Rebel why I can't seem to get a faster shutter speed then 1/200? I use it in every mode including Manual.

 

[Tiberius47]

If you are using your flash (be it the internal flash or a shoe-mounted flash) your shutter speed will be limited to the camera's X-sync, which is usually around 1/200 or 1/250.

The reason the X-sync exists is because of the way the shutter is constructed. Think of the shutter as two curtains (the kind that go up and down, like at the theatre, not the side to side kind like the curtains in your living room). There are two of these curtains. When you press the shutter, the first curtain drops away, exposing the film. Then, the second curtain drops down to stop the exposure. Then both curtains are moved back up to be ready for the next photo.


The shutter speed is how long the second curtain waits before it moves down to cover the sensor/film. That means that if you have a shutter speed of one second, the second curtain comes down one second after the first curtain moves away.

However, when you use a very fast shutter speed, the first curtain may not be all the way down before the second curtain starts coming down. So, the entire frame is never exposed all at once.

This causes a problem when using your flash, because the flash of light from a flash unit is so fast. If you used such fast shutter speeds with a flash, the flash would only be lighting a portion of the frame. To avoid this, the camera will limit the shutter speed to one where the entire frame can be lit.

If you have an external flash unit, this can be overcome by using the high-speed sync mode. This causes the flash unit to deliver a series of pulses of light instead of a single burst. These pulses are delivered way to fast for a human eye to be able to tell them apart (it's about 70 pulses per second on the Canon 580EX flash). This results in a bit of a loss of flash range, but not too much. This is invaluable for using fill flash on a brightly lit day. I don't know that any camera allows the high-speed sync flash with the built in flash, however.

That's all I can think of, and if you are indeed using flash, then this is certainly the problem. Use an external flash capable of HS sync if you can, but if you can't, then the only way you'll be able to get a faster shutter speed is to turn off the flash.

If you aren't using flash, then it may be that there is a problem with the hotshoe, tricking the camera into thinking there is a flash on the shoe. If this is the case, then I recommend you take the camera in to be serviced.

if it's neither of these, then I am stumped!

 

[TCimages]

If you are using flash, this would be the highest synch speed for the rebel. If you aren't using flash and you are in manual mode, I can't think of any reason why you couldn't go as high as you want.