I have been trying to figure out how to take night and low light pics, but they are all turning out blurry or too dark when I use the night setting. Is there something I am missing? Should I be changing the shutter speed? And I didn't know anything about changing the ISO, so should I be doing something with that as well?
I want to know the answer to this question. I was under the impression that they end up a bit blurry because the shutter is open longer and the slightest hand movement can cause that. Is that why you would want to use a tripod? But I am still learning how to use my camera and I have had it for almost nine months now! Any assistance would be really helpful!
Pixiedust - you've got the right idea.
A basic breakdown of the three primary controls of a camera (any camera) are this:
1. Shutter speed - the faster the shutter, the less time it's staying open, therefore the less light it's actually letting through to the sensor. Therefore, you need lots of light coming through to be able to use a fast shutter speed. The slower the shutter speed, the more light the sensor can absorb in a lower light scene, but the flipside of that is that if anything is in motion at all, be it the camera, the subject, a tree branch in the background, etc...the longer shutter is going to 'see' it throughout the movement. A 3 second shutter will be 'seeing' the scene for 3 whole seconds without closing it's eye...so if something moves through that 3 seconds, the sensor is going to pick it up everywhere it goes, like a long streaky blur. So you either have to use fast shutter but need lots of light, or a slow shutter and need complete stillness.
2. Aperture - this is like the iris of your eye - a bigger aperture opening (denoted rather confusingly as a SMALLER F-stop number) lets in much more light than a smaller aperture opening (bigger F-stop number). So in bright daylight scenes, you tend to want much smaller apertures to get rid of all that excess light not needed. In a low light situation, you want a bigger aperture to let in as much light as you can.
3. ISO - In film days, the film speed denoted the sensitivity of the film to light. More sensitive film could be used in lower light situations to get the shot you needed at a faster shutter speed to avoid blur, even when the light was low. The downside was that there tended to be alot more noise, or graininess, in the shot. Digital ISO works much the same way - it basically turns up the gain on the sensor so it is much more sensitive to even the smallest amount of light - the higher the ISO, the more sensitive it becomes. At the same time, the more sensitive the sensor becomes to noise and graininess. P&S cameras often can't shoot much above ISO400 as they get so noisy or grainy as to obscure the subject. Most cameras have some type of built-in noise reduction that will get rid of alot of this noise, but the downside is that while it wipes away the noise, it also wipes away alot of the detail.
There are three primary types of night shots.
1. Flash. That's the most obvious - just use a flash to light up whatever scene you're taking. Problem is, that tends to only be useful for close objects or portraits, unless you have a heck of a powerful flash.
2. Handheld high ISO. This type of night photography is fairly straightforward - when you want to take snapshots, handheld, at night, just like you do during the day, you need a whole lot of light coming through the lens for the sensor to pick up. Unfortunately at night, there usually isn't a whole lot of light, unless you're standing in front of a very well lit subject (like a Vegas hotel sign). So you have to turn up the ISO so your sensor can perform at normal shutter speeds even in the dark. It helps to have a very wide aperture lens too - those lenses marked with F1.4 or F1.8 or so are best, because they can let in so much light. The downside to wide open apertures is that they tend to significantly shrink your 'depth of field', or how wide the area is that the camera is in focus. At F1.4 and 50mm, you can focus on the face of someone 15 feet away, and have everything out of focus just 6 inches in front of and 6 inches behind that face.
3. Tripod-mounted slow shutter. This type of night photography is usually the type folks refer to. It is the kind shot usually with the lower ISO, to avoid noise, apertures somewhere in the middle, so as not to be too shallow on the depth of field, and a long shutter speed, usually in the seconds, to pull in all the light needed for a shot. This is most effective for landscape shots, buildings, etc., since they do not move while taking that long shutter. The tripod (or a flat, level surface) is needed to avoid even the tiniest vibrations to the camera when pressing the button, which will introduce blur in the shot. For these, it's usually best to turn the flash OFF, which can cause the camera to mis-meter the scene if you're in a nightshot more or program/auto mode. Once you get the hang of it, A or M mode is usually best for these shots.
Using ISO or not is based on the situation. Sometimes, you may need it...if you take a shot in a night scene mode that still comes out too dark, then raising the ISO may allow you to brighten it up enough to get the shot. Or, leaving the ISO alone, and manually choosing a longer shutter speed (requiring the camera to be on tripod or level surface), can also get you the shot you need.
Hope that helps!