Preparing Photos for Presentations, Documents and Websites

A great photo can look terrible in a presentation if it's stretched, blurry or enormous. Getting size and format right is straightforward once you know a few basics.

Slides and presentations

Most modern slides use a 16:9 widescreen ratio, and older ones use 4:3. Check which ratio your presentation uses.

• Size: A full-screen photo needs to be about 1920 × 1080 pixels for a standard high-definition display, and more for 4K displays. Larger photos can be used, but will just make the file heavier.
• Crop the photo to the slide's ratio, so it fills the space without stretching.
• Don't stretch. Pulling the corners to fit distorts the image. Crop instead.
• Leave space for text. Photos with plain areas, such as sky or wall, make good backgrounds.
• Keep it consistent. Use a similar style of photo throughout.

Documents and reports

• Photos printed on A4 or letter paper need at least 200 to 300 pixels per inch at their printed size to look sharp.
• Keep file sizes reasonable, because large photos make documents slow to open and share by email.
• Add captions to explain what the photo shows.

Websites and blogs

• Resize before uploading. A photo straight from a phone may be many megabytes, far larger than a web page needs.
• Use JPEG for photos and PNG for graphics with sharp edges or transparency.
• Compress to a reasonable quality, since a small decrease is usually invisible, and page loading gets faster.
• Crop for the layout, such as a wide banner or a square thumbnail.
• Write alt text describing the image for readers using screen readers, and for search engines.

Choosing the right photo

• Sharp and well-exposed photos work best.
• Simple compositions are easier to read on a slide.
• People add warmth, but check that you have their permission.
• Avoid busy images that compete with text.

Consistent editing

Apply the same colour treatment, so that a set of images looks like it belongs together. Slightly increasing contrast can help photos stand out on screens.