How to Adjust Dots Per Inch

Adjusting dots per inch makes your photos right for all different media.

Adjusting dots per inch, or DPI, is one of the basic concepts in shooting and digitally editing photography you will need to get a good grasp of to make the best use of your digital SLR camera, and to get your prints and digital images looking their best. Adjusting dots per inch is easy enough, and varies little from one photo editing program to another.

Instructions

1. Get a good grasp on what dots per inch, commonly abbreviated to dpi, means. Also called pixels per inch, this measurement is used to determine the resolution of an image. An image with high dots per inch relative to a fixed size, for example 11 inches by 17 inches at 300 dots per inch, is much more useful in different situations. This is because the image can be blown up very big, or sized down very small, while still retaining its clear picture.

2. Open up Adobe Photoshop. Open your image, and then in your menu in the top left corner of the screen, select the "Image" tab. Scroll down to where it says "Image size..." and click.

3. Study the dialog box that comes up. Your keys here are the image dimensions, in pixels by default, and the "Resolution" variable under the "Document Size" tab. Depending on where you got your image, the resolution will be different, but it is most likely at either 72 dots per inch, or 300 dots per inch.

4. Decide what you wish to use your image for. For printing, you should shoot for a resolution of 300 dots per inch, while for publishing a photo on the web or any computer uses, 72 dots per inch is sufficient.

5. Click the "Resample Image" check box so that it is not checked. This will allow you to resize the image without actually changing the file at all. Now adjust to your desired dots per inch. You will notice the "Document Size" dimensions, in inches, change when you adjust the dpi.

6. Recheck the "Resample Image" check box and now change the image size to the desired size for your use, for example 8 inches by 10 inches. Now you are actually changing the image itself, and not just the way Adobe Photoshop reads the file, so make sure you have it right. Voila! You have your new image adjusted to the correct dots per inch for your application, at a size that is most usable to you. Easy!

Tips & Warnings

• Remember, 72 dots per inch for the web, 300 dots per inch for printing. If your image is not high enough quality to print at a decent size at 300 dots per inch, you can go a little lower, but consider using a different image or allotting less space.

• If you are going to be doing any image resizing in Photoshop, make sure you have the "Constrain Proportions" checkbox clicked on before changing any variables, such as the horizontal inches. This will avoid distorting your image.