When you look through your viewfinder near the bottom left you will see a little
F with a number after it - that is your current "
aperture" or "
f-stop". just to the left of that will be another number - that is your current
shutter-speed setting. If it shows
60 the
shutter-speed is 1/60 second,
250 is 1/250th of a second, etc. If there are quote marks like this
" after the number it means the
shutter-speed is now in seconds, so
3" means 3 seconds, whereas a
3 by itself means 1/3 of a second. Thanks for this reply that is where I thought it was but mine just say's 0 with the little lines "0"""""" and at the end it has a arrow but no matter what setting I have it on it still says the same 0"""""' the 0 does move along the little """""" but no number
How the
shutter-speed is set depends on what mode you are in - if you are in auto-mode the camera sets both the
aperture and
shutter-speed for you. If you are in
aperture priority "A" mode you use the command dial to set the
aperture and the camera selects the correct
shutter-speed. If you are in
shutter priority "S" mode you select the
shutter-speed with the command dial and the camera selects the correct
aperture. Note that there are limits to
aperture and
shutter-speed and the camera will sometimes show "HI" or "LO" for
shutter-speed or
aperture if the limits are exceeded. (I've assumed your D3100 works like my D50 in this respect, but check you manual to be sure).
Trying some of the exercises in the New To Photography forum will help you get your head around all this stuff.
Cheers.