Canon has a variety of digital SLR cameras available that range anywhere from $550 to almost $8000 in price. Faced with all these options, you might be confused as to which Canon digital camera SLR will provide you with all the features you need. Do you really need an $8000 camera, or will a camera that is less than a tenth of the price serve you just as well?

Comparing Canon Megapixels

One of the biggest differences between different Canon digital camera SLRs is in the picture resolution. One of the cheapest Canon SLR cameras, the Rebel XS, has a resolution of 10.1 megapixels, whereas its most high-end camera, the EOS-1Ds Mark III, has a resolution of 21.1 megapixels. More megapixels is generally associated with better picture quality, but do you really need that many?

If you print your photos at standard sizes, a picture with 10 megapixels does not actually look exceptionally different from one that is 21 megapixels. It is only if you are making large prints that the number of megapixels really becomes important. Even 10 megapixels will print a high-quality photo up to 12x16 inches in size but if you want to print images larger than that, you will probably want to go with a camera with more megapixels.

Another reason you might want more megapixels is that it gives you more freedom to crop your image and still end up with a high-quality standard-sized photo, even when the cropped picture is significantly smaller than the original.

More megapixels take up more memory on your camera’s memory card and in your computer, and need to be greatly reduced when they are being sent as e-mail attachments or uploaded to most websites, so if you do not intend to make large picture prints or significantly crop your images, more megapixels might actually be more of a burden than a benefit.

Crop Factor

Most Canon cameras have a crop factor of 1.6. This means that, compared to a film SLR camera, the Canon digital camera SLR sensor has cropped the image you are photographing by a factor of 1.6, requiring you to use a lens with a smaller focal length to capture the same span of landscape that you would with a film camera with a larger focal length lens.

Canon’s higher-end cameras have a crop factor of 1.0. In other words, these cameras will take photos with exactly the same range as a film SLR camera. Of course, these cameras are also much more expensive, however, so unless you are a professional landscape photographer you may just want to go with a cheaper camera and a smaller focal lens to take your wide landscape shots. If you take mostly close-up or portrait photos, crop factor should not be too much of an issue.

ISO and Noise

When you take a picture with your digital camera in a low-light setting, the shutter automatically stays open longer so that the sensor can have more time to absorb light. Leaving the shutter open like this can create blurry pictures, however, if the subject of the photo moves even slightly or if your hands shake at all when you are holding the camera.

SLR cameras have something called ISO solves blurry picture problem by making the sensor absorb light faster so that the shutter does not need to be open as long. This allows you to take pictures without a flash when you are in an area with low light without having your pictures turn out as a blur.

The higher the ISO number, the faster the sensor absorbs light. All Canon digital camera SLRs have different ISO settings from you to choose from, but the cheaper cameras, such as the Rebel, do not have as high ISO settings as the more expensive cameras, which generally have settings for up to 3200.

Typically, the higher the ISO, the grainier a picture will turn out, but Canon cameras have been praised for their ability to filter out this visual noise. In large photos, some noise may be visible at an ISO of 400, but typically in regular-sized photos, picture quality is still almost perfect at ISOs as high as 800. The more high-end the Canon camera is, the better it typically is at filtering visual noise, even at high ISO settings.

There are of course other factors to take into consideration when choosing which Canon digital camera SLR is right for you, such as dust control, image stabilization, continuous drive, and autofocus, but these are three of the main factors you can compare between cameras when trying to decide which to buy. If you are like most people who just want to take pictures for themselves or their family and friends, a cheaper SLR will probably produce high enough quality photos to serve your needs just fine.

If you are really enthusiastic about photography, print a lot of large photos, or take a lot of pictures in low-light settings, however, you might want to consider spending the extra money on a more high-end camera.