Resolution revealed.

What is resolution and why is it important in photography? Resolution is the ability to distinguish detail in an image. Consider the ability to resolve detail in your vision. The best part of your vision is where you look when you try to see fine details; we commonly call it central vision and it is located on a part of the retina called the fovea. As you read this, the words move across that part of the retina and there is enough detail there to distinguish the shape of each letter. People with central vision loss, related to macular degeneration, have a hard time reading because they can't acquire enough detail to discern letters. More detail equals better resolution.

Several factors that affect resolution in digital cameras. Chief among them is the number of pixels on the sensor. A pixel, essentially a coloured dot, combines with neighbouring pixels to produce part of the image. They all work together to produce the picture you see. The more pixels there are, the more detail is captured. Detail equals resolution.

The above image shows the photo I shot of a house finch with a 20 megapixel camera. Twenty megapixels means twenty million pixels (dots of colour). The original shot, on the left, is the entire frame as I saw it through the viewfinder. The bird is small and difficult to see well. Since there is so much resolution present, the part of the shot with the bird can be enlarged, by quite a bit it turns out. Taking a small part of an image and enlarging it is called cropping.

Most of the time we don't really need as much resolution as the camera provides. Old three megapixel cameras could produce perfectly good pictures because of that reason. The difference is that you can do a lot more cropping with modern cameras capable of producing 20+ megapixel files. This is a boon for wildlife photographers like myself where serious cropping allows the production of images previously impossible to obtain. Some cameras have even more resolving power, boasting sensors with 24, 36, 50, and even 100 megapixels.

A second factor affecting resolution relates to the camera's lens where focus and sharpness play important roles. Cropping a blurred image does little to improve detail. Better quality lenses allow captured details to be more precise. The combination of pixel count, lack of blur, and high sharpness allows one to produce cropped pictures of exacting detail.

Most of the time high pixel counts and expensive equipment are not needed to produce the images we interact with daily. For those moments when significant cropping is required or fine details from a shot (like the license plate number from a dashcam) need to be extracted, resolution is the ticket. Sometimes literally.

Thanks for reading.     Ericspix     Eric Svendsen