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Position:Home>Visual Arts> Why is Shutter speed limited when shooting with flash ?Question: Why is Shutter speed limited when shooting with flash !? I own an Olympus E-410, and I would appreciate if someone could explain why is the shutter speed reset to 1/180 when flash pops up, if i set it to shorter values !? I would like to "freeze" action more and I have learned that to acquire this, one has to set shutter speed at lower values!. Would an external flash allow me to set the shutter speed to lower values !? Sorry if this seems like a lame question to the more advanced photographers out there!.Www@QuestionHome@Com
Best Answer - Chosen by Asker: The shutter on an SLR consists of two curtains!. When you release it, one curtain literally slides open!. When the programmed exposure is complete, the second curtain slides closed!. At high shutter speeds, the second curtain is close behind the first!. In fact, it can get so close that if you were to see what was happening in slow motion, it would look like a bar moving across the surface of the sensor, rather than the sensor being fully exposed!. In your camera, 1/180 sec is the shortest exposure where the sensor is fully exposed to the flash!. This means that the first curtain is fully open and the second has not yet started to advance!. The flash duration is much shorter than the exposure!. It is on the order of 1/1000 to 1/10,000 sec!. So, if you used a higher shutter speed, the portion of the image that will experience the proper exposure from the flash is only where the open space between the first and second curtains happened to be when the flash fired!. Another poster said that shorter exposures would not allow the full amount of light from the flash because the flash duration would be longer than the exposure!. This is not true!. The flash duration is almost always shorter!. Some Canon cameras and flashes are capable of what is called high speed synch!. I'm not sure what they do to overcome the limitation imposed by the first and second curtain!. My hunch is that they extend the duration of the flash somehow!. But don't quote me on that!.Www@QuestionHome@Com Its called flash sync speed!. Set the shutter too fast and it will close before the flash has fully fired!. Actually 1/180 sec!. is a fairly fast shutter speed!. An external flash will require the same shutter speed as the one built into the camera!. You will, however, get better results with an external flash since its more powerful and capable of bounce flash!. Be happy you didn't live back when most cameras had a flash sync speed of 1/60 sec!. EDIT EDIT EDIT I guarante you that if you use a shutter speed faster than 1/180 sec!. your pictures will be ruined!. Back in the day I occasionally accidentally bumped the shutter speed dial from 1/60 sec!. to 1/125 sec!. and those frames were 1/2 black!. Try using your flash with a shutter speed of 1/250 sec!. or higher and let us know how the picture turned out!.Www@QuestionHome@Com |