slow the shutter speed?

[Tanya Kurnik]

im not sure if im in the right place for this question. tonight im going out to photograph a popular bridge. its going to be lit up a variety of colors. underneth it is a high traffic road. how do i get the blurred effect of the cars moving? like i said, this will be at night. i have a nikon D3100 and i know im supposed to slow the shutter speed but dont know how?

[zona5101]

You will select either shutter priority "S" on your nikon dial (or "M" for manual).
If you pick S, the camera will pick the aperture. (In manual you will pick both)
I would suggest you take several versions of the shot using different shutter speeds. You will need a stable tripod or at least someone stable surface you can set your camera on. You may try starting at a 1/15 or a sec and decreasing the shutter speed with subsequent shots.
Good luck

[Tanya Kurnik]

perfect, thanks! i was going to try both those settings but wasnt sure.

[inkista]

I'd actually recommend using Manual over Shutter priority for night time shooting. The matrix/average/center-weighted metering modes are likely to bias you towards overexposure. That's when you start getting brown skies in night shots. If you want the night sky to stay black, you'll need to override that, and Manual just makes it easier, since you're going to be messing about and trying a number of settings anyway.

+1, also on the tripod. A good sturdy tripod. Not one that trembles in the breeze. Using the timer, cable release, or remote might also help. The cable release in particular is great if you're going to be doing minute-long exposures, so your finger doesn't get tired of holding down the shutter button in bulb-mode. Don't know if Nikons work the same way, but on my Canons when you want to go longer than 30 seconds, you have to use bulb mode. In this mode, the shutter will be held open for as long as you depress the shutter button. With a cable release, you can lock the shutter button in place so you don't have to hold it, or with a remote, the camera will open the shutter on the first press, and close it on the second.

Don't forget that you can also stop the lens down (use a smaller aperture) for increased depth of field and use a lower iso setting for less noise. Everybody's first instinct when shooting at night is to try and maximize the aperture/iso to get more light faster, but if you're on a tripod you don't need to worry about getting handholding shutter speeds. And the smaller apertures like f/11 or f/16 can get you the "star" effect on lights. And the longer your exposure time, the longer those light trails will get.

The really big key, here, is to be shooting from a stable platform. This is why good tripods cost.

[Tanya Kurnik]

im not sure if i uploaded the photos but here goes

[Tanya Kurnik]

http://digital-photography-school.co...ure54082-a.jpg