Size specific problems

[monvural]

When submitting photos for various things there's almost always a size limit. Is the only way to reach that size limit decreasing the size of the image itself? I've also changed it from 300 resolution to 72 resolution. Anything else?

 

[drlynn]

There are several ways to decrease file size.

1. Decrease image resolution. For web pics, 72 ppi is appropriate.

2. Decrease image size. Most people have their monitor set at 1024x768 or 800x600. For this reason many web sites suggest 800 pixels as maximum image width so people don't have to scroll sideways.

3. Increase image compression. The higher quality your jpg image, the bigger the file. Decreasing the quality % when you save a jpg file will decrease file size.

Here's an example:

The original file for the colorized picture I posted in the Photo Gallery is 3.5X4 at 600 ppi. The file size is 19.8MB as a Photoshop document. When I save it as a .JPG file at 100% quality, it reduces to 2.4MB. Reducing the file to 800x680 reduces the file size to 340KB. Reducing image quality (increasing JPG compression) to 80% reduces file size to 163KB.

Most of the time, you have to combine the different methods of reducing file size to get an acceptable result that doesn't show too many compression artifacts or cause dial-up users to get tired of waiting on the download.