What shutter speed to use in low light action photos?

I've got a nikon d3000 ( with a more or less useful ISO of 800) + 35mm f1.8 lens. I've started using Program mode without the flash but noticed some of my shot have become blurred. What shutter speed should I use? Or other settings for that matter, for the photos not to blur and not to be too dark either. I'm planning to take my camera to a concert and would hate for this to happen again.

There's no single answer. Every low light shot is different. ISO (ASA) of 800 may still be too fast for the light. F1.8 should be good. But any movement at all in low light will blur even the best camera. Also low F-stops will give a short depth of field (depth of focus).

Best advice is to create a similar light condition at home and experiment. Start at 400 at a medium f-stop and work up or down. Generally program modes are really only useful if you're gonna take a lot of shots in similar conditions. You have a good camera in the D3000. If you're just taking snapshots, the D3000 is overkill. DSLR's, even budget ones, are designed for people that want to experiment. Learn to use all of it's features and how various setting affect your shots and you'll enjoy your equipment & your experience so much more.

Under any lighting conditions your shutter speed is dependent on the ISO and aperture used. Your 35mm f1.8 is a good low-light lens and when combined with ISO 800 may give you a sufficient shutter speed if the lighting is adequate. You can improve your chances by using Single Point AF if the subject is stationary or Dynamic Area AF for moving subjects and by using Spot Metering which meters a 3.5mm circle or about 2.5% of the frame. By using Spot Metering your camera won't be trying to meter the entire scene which will usually result in a too-slow shutter speed.

I also suggest using Aperture Priority with the flash OFF and, using the previous suggestions, checking the shutter speed set by the camera. If its still too slow then use ISO 1600 and then refer to this article to deal with the resultant digital noise.

http://www.shutterbug.net/equipmentreviews/software_computers/0309noise/index.html

This site will also give you a better understanding of shooting in low-light situations:

http://www.calculator.org/...osure.aspx Just choose a Scene from the list and an ISO and then look at the table of f-stop/shutter speed combinations.

Set the camera to Aperture Priority, select the smallest f/number and start shooting at ISO 800 going up bit by bit. Whatever shutter speed the camera sets is what you deal with. Test using higher ISO values until you get non-blurred action shots. Using the largest aperture (lowest f/number) and raising the ISO increases the shutter speed. You will need that to be at least 1/500s. The faster the better but you will have to compromise with grain with higher ISO values.

Depends on what you're shooting. If you're shooting something moving around, I would want my shutter speed to be at 1/250 or faster. If I'm shooting something that's static, 1/50th of a second should be fast enough.

I would recommend using Aperture Priority (A) mode, as it allows you to select the widest aperture which allows the maximum amount of light in, thus allows for higher shutter speeds. Take a few test shots, and if you're still getting blurred shots, raise your ISO setting.

I would avoid Shutter Priority in most cases as it's very easy to get underexposed shots in this setting. Since there's such a huge range of shutter speeds to choose from, you can easily select one that is too high, and the camera can't compensate with its more limited aperture and ISO settings, thus resulting in underexposure (pictures coming out too dark).