Why are some photos different sizes?

Common Photograph Sizes Different sizes work in different environments—display larger prints or posters to bring attention to an event or service, and reserve smaller prints for display in homes or on counter space. Here are some of the most common photograph sizes.

What is considered high res?

Hi-res images are at least 300 pixels per inch (ppi). This resolution makes for good print quality, and is pretty much a requirement for anything that you want hard copies of, especially to represent your brand or other important printed materials.

What size is a 4×3 photo?

The 4×3 picture is 1/4th the size of the 16×12 so there has to be four times as many pixels per inch to reduce this picture to 4×3. Four times seventy two equals two hundred eighty eight pixels (dots) per inch.

Why is it important to consider the maximum size of an image?

Following is a list of reasons why you must limit your images and understand the importance of keeping file sizes of your images small. Big graphics make your pages load too slowly. Probably the most important reason why your image file sizes should be smaller is how people connect to the internet.

What two different things can the size of an image refer to?

The image size (or pixel dimensions) of an image is a measure of the number of pixels along an image’s width and height. For example, your digital camera may take a photo that is 1500 pixels wide and 1000 pixels high. These two measurements indicate the amount of image data in a photo and determine the file size.

Do images with the same size have the same amount of data?

Two images with the same dimensions contain the same amount of data but not necessarily the same amount of information. A pure white image contains virtually no information and can be compressed into a very small space (it is sufficient to store only the height and width in order to fully recreate this image).

Why does the second set of images have more storage?

The storage is generally proportional to the amount of details left in the image after compression. In your second set, the second image clearly has more details. This should be obvious compared to the first one which has huge expanses of uniform color which compress much better.

What is the difference between a plain image and a JPG?

A detailed image will require significantly more data than a plain one. This is because Jpegs are based on an equation. In order to save space when possible, pixels next to each other that are similar are remembered and put into a calculation. I have found that Raw images vary in size a little and truthfully I’m not quite sure why.

Why do I have to compress images to a certain size?

When an image contains more details it loses more details when compressed to a certain size, so this is desirable only if storage is limited. If you are working in Photoshop (or PS Elements), use the “Save for Web and Devices…”