While advances in technology have allowed for some excellent cameras, it has also made camera buying stressful and rather complicated. Which camera is best? Which camera offers more bang for the buck? While there's a lot of different factors that determine a digital camera's performance, there are three factors that will indicate image quality over any other elements: sensor size, maximum aperture and burst speed. Don't know what any of that means? That's okay, we've put together a simple camera buying guide that tells you just what you need to know.
Pay Attention to Sensor Size
Forget about megapixels. The biggest indicator of what kind of images you'll get from a camera is the sensor size. The light from the camera lens hits the sensor and it's the sensor that renders a scene into a digital image. The larger the sensor is, the more resolution you'll have in the photos. Larger sensors mean better performance in low light and better prints, even when enlarged.
The average sensor size for a basic point-and-shoot is 1/2.3”, though some budget models have smaller 1/3.1” sensors. Don't like fractions? That's okay (I don't either). To translate sensor sizes into dimensions, just type it in at http://www.sensor-size.com, if looking at it in millimeters is easier for you to compare.
The typical sensor size depends on the size of the camera. Most point-and-shoots, again, will be somewhere around 1/2.3”, but there are some compacts with a better 1/1.7” sensor and Sony makes a few with a one inch sensor. When you get into interchangeable lens cameras, the sensors also get bigger. Some mirrorless models only have the same size sensor as point-and-shoots, but most have a Micro Four Thirds Sensor, or the larger APS-C. Full frame is the size most professionals use, though you can get even bigger with medium format (for a whole lot of money).
To keep it simple, just remember that bigger is better when it comes to camera sensors.
For Aperture, Smaller Numbers Are Best
Photography is all about light, and to find out how a particular camera handles challenging lighting, look at what's called aperture. The camera lens lets in light—the aperture is what determines how much light. Just like you'll get more sunshine from a bigger window, a wider aperture will let more light in to your photos. A nice, wide aperture is essential for taking clear images in low light.
When it comes to sensor size, bigger is better, but when it comes to aperture, smaller numbers are best. The aperture is indicated by a number with an f in front of it. The best aperture is around f1.8 and many basic compacts have a lens with an f3 or above. Often, you will see two aperture numbers, written like this: f1.8-5.6. What this means is that when the camera isn't zoomed in, you can use the nice wide f1.8, but, when the camera is zoomed all the way in, the maximum aperture is only f5.6.
Look for the maximum aperture in the technical specifications and remember smaller is better when it comes to f-numbers.
After the sensor and lens, the third element that determines a camera's performance is the processor. Manufacturers will often specify what processor is inside, but it's often not much more than a name and perhaps a version number. A simpler way of determining how quickly a camera will perform is to look at the burst speed. The burst speed is how many pictures the camera can take in a single second, designated in fps (frames per second).
An example of images resulting from a 15 fps burst speed (Nikon 1 J3)
So what's a good burst speed? That depends on the camera model. Smaller cameras actually tend to have faster burst speeds than DSLRs, because DLSRs have a mirror that has to move every time a picture is taken. A good burst speed for an entry-level DSLR is 5 fps, but that's a little low for a compact camera, though not bad. The fastest compact and mirrorless cameras have speeds of 10-15 fps.
The Simple Camera Buying Guide: An Example
|Camera||Price||Sensor||Max. Aperture||Burst Speed|
|Nikon L30||$120||1/2.3 CCD||f3.2-6.5||1.1 fps|
|Nikon S6800||$220||1/2.3" CMOS||f3.3-6.3||9.4 fps|
|Nikon P340||$380||1/1.7" CMOS||f1.8-5.6||10 fps|
If you just look at the sensor size and maximum aperture, the L30 and S6800 appear very similar, though the L30 uses a cheaper sensor type. Based on just those two standards, the cameras are quite similar. But, if you factor in the burst speed, you can see why the L30 is the budget model at $120—it's quite slow.
The S6800 and P340, however, have very similar burst speeds, so close, in fact, it would be hard to notice a difference using them. But if you look at the sensor size and maximum aperture, it's clear the P340 will have the better image quality. The P340 has a bigger sensor and also a much wider maximum aperture. So, out of the three cameras, the P340 will have the better image quality.
Using sensor size, aperture and burst speed is a great way to get a quick first impression of a digital camera. But of course, there are more than three factors. To get more details on what each digital camera has to offer, browse through the camera reviews or look at the top cameras by category.