Shutter Speed Question

[john_gardiner22]

Hey guys I have a Canon S50, which is a dig. but has all manual features of most SLR's. My question to you is that whenever I play around with shutter speed and I make the shutter speed to long, say 7-15 seconds, my photos come out completely white. What can I do to stop this and get good action shots?

 

[MuffinJuice]

well 7 seconds is an awefully long time for a picture.
what's happening is; all this light is flooding into your camera.



a fifteen second shot would be best taken in a quite dark room.

ive taken several shots with all the lights on and a shutter speed of fifteen seconds. the photo comes out as if it were daylight.


if you adjust the ISO/ Apetrue, you will get darker shots, but not at 15 seconds.


an ISO of 50, compared to 400 will make a darker photo, and changing your apeture from f/2.8 to lets say f/8 will darken the shot as well. if you can, change the settings to a 4 second shutter speed, 50 ISO and f/8 and you may get an ok shot. play around with the variables until you recieve the outcome you want.



longer shutterspeed=more light on the film=brighter photo

 

[seanarmenta]

well...actually everything is relative. you do not need to change your iso setting! with digital, keep it at 100.

so long as your exposure remains the same, you can use any combination of shutter speeds and apertures. you just have to remember, that when you change one, you must change the other in the opposite direction.

if you increase your shutter speed, you have to use a larger aperture. conversely, if you decrease your shutter speed, you have to use a smaller aperture.

for example, 1/250 @ f2.8 is the SAME exposure as 1/15 @ f11.
f2.8 - f11 = 4 stops down
1/250 - 1/15 = 4 stops up

so let's say you meter your subject at 1/125 @ f8. you want to use a slower shutter speed to capture motion. let's say you pick 1/15, which is 4 stops slower. you would then need to adjust your aperture to f32, which is 4 stops smaller than f8.

now, if you want to capture motion (as opposed to freezing it) in your photographs, during the daytime you won't need to use anything slower than 1/2 second. at night, if you want to capture traffic trails, you will be able to use 20 seconds and slower.

sean