How to Reduce Noise on a Canon Rebel T5/1200D - dummies

How to Reduce Noise on a Canon Rebel T5/1200D

By Julie Adair King, Robert Correll

On the Canon Rebel T5/1200D, noise looks like sprinkles of sand and is similar in appearance to film grain, a defect that often mars pictures taken with high ISO film. The figure below offers an example.


Ideally, then, you should always use the lowest ISO setting on your camera to ensure top image quality. But sometimes the lighting conditions don’t permit you to do so. Take the rose photos in figure below as an example.

When the photographer shot these pictures, she didn’t have a tripod, so she needed a shutter speed fast enough to allow a sharp handheld image. She opened the aperture to f/6.3, which was the widest setting on the lens she was using, to allow as much light as possible into the camera.

At ISO 100, the camera needed a shutter speed of 1/40 second to expose the picture, and that shutter speed wasn’t fast enough for a successful handheld shot. You see the blurred result on the left in figure below. Raising the ISO to 200 allowed a shutter speed of 1/80 second, which was fast enough to capture the flower cleanly, as shown on the right in the figure.


Fortunately, you don’t encounter serious noise on the T5/1200D until you really crank up the ISO. In fact, you may even be able to get away with a fairly high ISO if you keep your print or display size small. Some people probably wouldn’t even notice the noise in the left image in the figure above unless they were looking for it.

But as with other image defects, noise becomes more apparent as you enlarge the photo, as shown on the right in that same figure. Noise is also easier to spot in shadow areas of your picture and in large areas of solid color.

How much noise is acceptable (and, therefore, how high an ISO is safe) is a personal choice. Even a little noise isn’t acceptable for pictures that require the highest quality, such as images for a product catalog or a travel shot that you want to blow up to poster size.

It’s also important to know that a high ISO isn’t the only cause of noise: A long exposure time (slow shutter speed) can also produce the defect. So how high you can raise the ISO before the image gets ugly varies depending on shutter speed.