Wednesday, October 3, 2012
Flash Synchronization in Cameras for Correct Exposure (post no.94)
This photo was taken by flash.....Then what is there?....It is to be understood that every flash has an automatic coordination between the shutter speed and flash, called Synchronization. Firing of the flash and recording image at the same time on the sensor.
In film SLRs and DSLRs too, there is limit of entering the flash light onto the sensor with a specific Shutter Speed....For example, if u own a DSLR, there are Shutter Speeds range from 30 sec to 1/4000th part of a second. ..There is also the duration limit of flash light emitted by builtin flash or external flash mounted on hot shoe. That is from 1/500 to 1/30,000th of a second......The difference in Speeds opening the shutter and the light thrown by the flash tube, does not match 'in time' with all the Shutter speeds as mentioned above. The flash light enters the camera at slow shutter speeds of individual cameras e.g. at 1/200, 1/250 and in few cases 1/500....This is 'SYNCHRONIZATION', when u get a picture correctly exposed by the light emitted by flash tubes. Thus the flash pix can be taken below 1/250,for example, to as below as your camera limit of 1/8th, 1/16th or even 30sec.
In auto cameras, the SS is controlled automatically by the camera itself giving u a correctly exposed picture within the limit of above shutter speeds. While using Manual mode, the shutter speed is to be set 1/250 or below while doing flash photography or as mentioned in ur camera manual.
The above picture was taken on 'auto' on my compact, which set Shutter Speed at 1/60 at f2.8, controlling the light output for correct exposure via built in sensor in the camera.