BY XAI LAO

Photoshop: How to Image Size a Photo for Web – Beginner’s Guide

ICT 710 | Learning Technologies | November 2011by Xai Lao

What is DPI or PPI

When working with digital photos, whether you download an image from the web or from a camera, every photo will have a specific DPI (Dots Per Inch) or PPI (Pixels Per Inch). Scanners, digital cameras and screens are all measured in PPI while printers are measured in DPI and both terms are used interchangeably by the pros and amateurs. Just so you know the difference. The rest of the tutorial will be referring to dip, however.

We won’t go into the mathematic details of mega pixels and how resolutions are determined from mega pixels for the sake of keeping this tutorial simple for beginners.

What is DPI or PPI (cont.)

In short, DPI can represent the resolution of an image. The general idea is, the higher the starting DPI, the more likely you can tweak the DPI down to the appropriate setting. It’s best to convert from a higher dpi to a lower dpi than vice versa to prevent pixelating photos (photos with squary effects).

VS

Pixelated Photo (wrong) No Pixelation (correct)

What is DPI or PPI (cont.)

Depending on their resolution (dpi) it can affect a photo’s quality when sending it to print. So setting a high dpi is recommended when printing photos or large prints. Other times, setting a lower dpi is more suitable when it comes to the web. Common settings for print are between 100 dpi and 300 dpi depending on the printer.300 dpi 200 dpi 100 dpi 72 dpi

Why Bother About Image Size

Different situations calls for different dpi Photos for Print (100-300 dpi depending on printers

used) Photos for Web (maximum of 72 dpi) anything higher

will look the same as 72Many benefits to image size

Save hard drive space on a computer Faster upload time for the web Faster download time from the web Get better results when printing a high resolution

photo Can speed up work process by working under lower

image size setting

Image Sizing Photos for Web

(note: regardless if working on a PC or MAC, the procedures are similar)

Step 1 Open Adobe Photoshop File > Open > locate an image

Image Sizing Photos for Web

(note: regardless if working on a PC or MAC, the procedures are similar)

Step 2 Your photo should now be visible, now enter image

size menu Image > image size

Image Sizing Photos for Web

(note: regardless if working on a PC or MAC, the procedures are similar)

Step 3 Image size window pops up Check - Constrain Proportions and Resample Image Change the “Resolution” setting to 72 Click “OK” button

Checked

Set to 72

Image Sizing Photos for Web

(note: regardless if working on a PC or MAC, the procedures are similar)

Step 4 Image will now be in

correct web format Save your image File > Save for web

Save image

Image Sizing Photos for Web

(note: regardless if working on a PC or MAC, the procedures are similar)

Step 5

Save for Web windowwill pop up

Choose “JPEG” Click save and give it a

file name Your photo is now formatted

for web usage

Quiz Time!

Take your time and try to answer the questions correctly.

4 questions all multiple choice

Question 1

What dip number should you save your photos when preparing it for the web?

1. 100 dpi2. 300 dpi3. 72 dpi

Question 1

Incorrect

Review “Why Bother About Image Size” slideto find the correct answer

Click Here for next question

Question 1

Correct

Although it isn’t required for all images to be in 72 dpi for web, most screens can only display up to 72 dpi. So it would be meaningless to have a website full

of 300 dpi mages used for background pictures.

Click Here for next question

Question 2

What does dpi stand for?

1. Dots per income2. Dice per inch3. Dots per inch

Question 2

Incorrect

Review “What is DPI or PPI” slideto find the correct answer

Click Here for next question

Question 2

Correct

Dots per inch is also the resolution of an image.

Click Here for next question

Question 3

Every digital photo has a dpi or ppi number?

1. True2. False

Question 3

Incorrect

Review “What is DPI or PPI” slideto find the correct answer

Click Here for next question

Question 3

Correct

As long as photos are still digital files, they will always carry a dpi or ppi number.

Click Here for next question

Question 4

The “image size” option is under what menu in Photoshop?

1. File2. Edit3. Image4. Layer

Question 4

Incorrect

Review “Image Sizing Photos for Web: Step 2” slideto find the correct answer

End of QuizClick Here to proceed

Question 4

Correct

The option can be found under the “Image” tab in photoshop

End of QuizClick Here to proceed

Quiz Complete - Congratulations!

Review

Working with images for print requires a higher dpi setting than images that are for web

Images for print are in the 100-300 dpi where web images are commonly just 72 dpi

It is best to work off a higher dpi image and down convert it to a lower dpi than vice versa

Photoshop is an easy tool to use when it comes to customizing and adjusting image sizes.

You have just finished a quick beginner’s tutorial on how to prepare a image for the web. The next time you plan to use a image for the web, you’ll know the correct dpi

setting to save each image under.

Additional Links

For more information you can visit these links

Cambridge In Colour website http://www.cambridgeincolour.com/tutorials/image-res

ize-for-web.htm

Scanning Photos for Web http://www.nicholsonprints.com/Articles/dpi.htm

End of Presentation