When initially setting up your camera, an important consideration is to choose the image resolution setting which determines what image size will be recorded to the cameras memory card.
The sensor in your camera is specified in megapixels which is simply the number of pixels in width times the number of pixels in height of your sensor. For example a Canon T6i camera, from the manual specifications page 384, the “L (Large)” setting records an image from the sensor as 6000 pixels in width by 4000 pixels in height. If we multiply those two numbers; 6000x 4000=24,000,000, results in a total of 24 million pixels, commonly referred to as 24 megapixels (mega meaning million). The T6i uses an APS-C sensor, the 24 million pixels fit within an area 22.5mm wide x 15mm high (see APS-C Canon in the Sensor Comparisons diagram below).
The “Large” setting on most cameras is a best fit that maximizes the number of pixels that can be recorded by the camera sensor. It is recommended to set your camera to the “Large” setting.
To Set the image recording quality for the Canon T6i refer to the manual on page 115. There are two (2) settings to consider; 1. image quality (includes image type Jpeg or RAW), and 2. aspect ratio.
As an example, the Canon T6i image quality settings are shown in the table below. If you want to shoot with the highest quality Jpeg; 1. press the menu button, 2. under the “camera 1” tab select “Image Quality” using the “▲” and “▼” buttons then pressing “Set”, 3. Select the first “Large” option using the “◄” and “►” buttons and then pressing “Set”.
As an example, if you want to shoot in RAW on the Canon T6i; 1. press the menu button, 2. under the “camera 1” tab select “Image Quality” using the “▲” and “▼” buttons then pressing “Set”, 3. Select the “RAW” option using the “◄” and “►” buttons and then pressing “Set”.
The aspect ratios available on the Canon T6i are; 3:2, 4:3, 16:9, and 1:1. To many this is a confusing topic however, it is simply the relationship between the width and the height broken down to the lowest whole number. Lets do a few examples with some basic math.
Example 1: Let’s take the Jpeg “Large” size for the Canon T6i from the table above, we see that the pixel size is 6000 pixels wide and 4000 pixels high a 6000:4000 ratio. So now lets simplify it; if we divide 6000 by 1000 we end up with 6 and if we divide 4000 by 1000 we get 4 which leaves us with a 6:4 ratio (notice we are dividing each number by the same number 1000). Lets simplify it further; if we divide 6 by 2 we get 3 and if we divide 4 by 2 we get 2 which leaves us with a 3:2 ratio. Hopefully you now see that 6000:4000, 6:4, and 3:2 are all the same ratio, we usually specify the ratio with the smallest whole numbers in this case 3:2, also note that 3 divided by 2 equals 1.5 and from this number we can make up a table for each ratio to use as a lookup to more quickly identify the ratio.
Example 2: If we take the 4:3 ratio and divide 4 by 3 we get 1.333. Now lets take the “Large” 4:3 pixel values from the table above; 5328 pixels wide by 4000 pixels high. Lets divide 5328 by 4000, the result is 1.332 which we see is very close to 1.333. Hopefully you now see how to simplify the determination of the image ratio when you know the pixel width and pixel height.
As an example, if you want to change the aspect ratio setting on the Canon T6i; 1. press the menu button, 2. under the “camera 3” tab select “Aspect ratio” using the “▲” and “▼” buttons then pressing “Set”, 3. Select the desired Aspect ratio “3:2, 4:3, 16:9, or 1:1” using the “▲” and “▼” buttons and then pressing “Set”.
From the diagram/table below we can see the “result” of dividing the width by the height for various ratios. Use this table as a lookup table to help with figuring out the ratio when you know the width and height of the camera sensor or digital image, with the method shown in “example 2”.
One more thing about “ratio”. Looking at the Canon T6i image quality size comparison table below lets compare the the “Large” values for the various available ratios. Notice that the 3:2 ratio results in the largest size image while the 1:1 ratio results in the smallest size image. Typically its best to choose the ratio with the highest image size and crop the image later in post processing. However, if you are shooting in Jpeg and want to be able to go directly to print you can set the aspect ratio to meet your needs. “A word of caution, if you are changing the aspect ratio be aware that it may not always fit your shooting scenario so remember to set it to the desired aspect ratio before you start shooting”. You can always shoot with a 3:2 ratio and use the Kiosk when submitting your images to be printed at a photo lab which allows you to crop your images, however, you could end up cutting of parts of the photograph as the image when shot may not have left enough room for the print size chosen.
Take some time to go over this lesson there is a lot of information here and it does take some time to digest. In our next lesson we will discuss the differences between shooting in Jpeg vs RAW.