I am asked frequently what resolution should files be made in. It is a slightly tricky question because it depends what you are doing with the image. Let’s clear one thing up first – for displaying on screen it is totally irrelevant what the resolution is. That’s confusing I know but if you have an image that is displayed at say 800 pixels wide, whether the original is 100ppi (pixels per inch) or 50,000ppi it will still only display at 800 pixels wide and look exactly the same to you and me. The resolution is really irrelevant. The ONLY thing that is affected is the size of the file being stored. Here’s a real example…
72 pixels per inch
300 pixels per inch
Can you see any difference? I can’t and the truth is there IS NO DIFFERENCE, except in the file sizes stored.
Both images are 400 pixels wide x 250 pixels high. It doesn’t matter what the resolution is, they will both display at that size because that’s the size they are. Even if the second image was 3,000ppi it would still only display at 400 pixels wide and therefore look no different to the first one.
The difference comes when you want to change the image in any way. If you want to manipulate it, retouch it, enlarge or re-print it. Then resolution DOES matter. In the simplest possible terms, computers store data as information relating to each pixel. Therefore the more pixels there are, the more data is stored, the more data that can be manipulated and the better the end result. That’s why when retouching I ask for images with a minimum resolution of 3,000 pixels on the longest edge of the final result you are looking for. If you want an 8″ x 10″ final image, the file wants to be 3,000 pixels on the 10″ length.
There are limits of course, ideals and specific recommendations for different needs. Take a look at my website for a much more descriptive ( more boring lol ) description if you would like. The full description is here. Otherwise I hope you find this little snippet useful and come back for more soon.