How to Set Image Quality on a Canon Rebel T5/1200D Camera
To choose an Image Quality setting on the Canon Rebel T5/1200D, the first decision you need to make is how many pixels you want your image to contain. Pixels are the little square tiles from which all digital images are made; pixel is short for picture element. When describing a digital image, photographers use the term image resolution to refer to the number of pixels it contains.
Every image starts with a specific number of pixels, which you select on your camera via the Image Quality setting. You can choose from five options: Large, Medium, and Small (1–3), represented by the initials L, M, and S (1–3). The table below shows the pixel count that results from each option. If you select Raw, images are captured at the Large resolution value.
|L||Large||5184 x 3456 (18MP)|
|M||Medium||3456 x 2304 (8MP)|
|S1||Small 1||2592 x 1728 (4.5MP)|
|S2||Small 2||1920 x 1280 (2.5MP)|
|S3||Small 3||720 x 480 (0.35MP)|
In the table, the first pair of numbers in the Pixel Count column represents the pixel dimensions — the number of horizontal pixels and the number of vertical pixels. The values in parentheses indicate the total resolution, which you get by multiplying the horizontal and vertical pixel values. This number is usually stated in megapixels, or MP for short. 1MP equals 1 million pixels.
Resolution affects your pictures in three ways:
Print size: Pixel count determines the size at which you can produce a high-quality print. When an image contains too few pixels, details appear muddy, and curved and diagonal lines appear jagged. Such pictures are said to exhibit pixelation.
Depending on your photo printer, you typically need anywhere from 200 to 300 pixels per linear inch, or ppi, for good print quality. To produce an 8-x-10 print at 200 ppi, for example, you need a pixel count of 1600 x 2000, or about 3.2 megapixels.
Even though many photo-editing programs enable you to add pixels to an existing image — known as upsampling — doing so doesn’t enable you to successfully enlarge your photo. In fact, upsampling typically makes matters worse.
Screen display size: Resolution doesn’t affect the quality of images viewed on a monitor or television, the way it does for printed photos. Instead, resolution determines the size at which the image appears. Remember that you need way fewer pixels for onscreen photos than you do for prints. In fact, even the Small resolution setting creates a picture too big to be viewed in its entirety in many e-mail programs.
File size: Every additional pixel increases the amount of data required to create a digital picture file. So a higher-resolution image has a larger file size than a low-resolution image.
Large files present several problems:
You can store fewer images on your memory card, your computer’s hard drive, and removable storage media such as a DVD.
The camera needs more time to process and store the image data, which can hamper fast-action shooting.
When you share photos online, larger files take longer to upload and download.
When you edit photos in your photo software, your computer needs more resources to process large files.