Image Resolution Part 2: digital photos
Digital PHOTOS — What size to make my photo before placing it on the slide
Digital camera CCD chips and screen sizes are not evolving at the same speed. This is where the problem has come from. Fifteen years ago, PowerPoint slides were projecting at 640 x 480 ppi. The first Apple camera took photos at 640 x 480. Projectors had the same low resolution. The number of pixels per inch on monitors has grown from 72 ppi to many more today, on either Windows or Macs.
Today, desktop screens average 1920 x 1080 ppi, projectors lagging a bit behind, and digital camera CCDs providing photos with sizes way ahead of the pack at 5, 10 thousand pixels wide. Way more than required to use on a PowerPoint slide. This isn’t bad, it allows you to crop photos and use only that part of the image which you need.
If you don’t bother formatting before you import into your slide, you may have issues of PowerPoint file size down the road. Just to give you an idea, have a look at the following table, showing photo dimensions and their file sizes. This is an example and does vary depending on the amount of detail in a photo as well as the amount of JPG compression used.
640×480 pixels at 80% JPG compression, in this photo will add up to 93 KB
640 x 480 pixels, @ 80% JPG compression gives you a file size of 0.093 MB (93 KB)
1024 x 768 pixels, @ 80% JPG compression gives you a file size of 0.219 MB
1152 x 864 pixels, @ 80% JPG compression gives you a file size of 0.277 MB
1280 x 960 pixels, @ 80% JPG compression gives you a file size of 0.343 MB
3968×2976 pixels, the original image, from a low end camera is a huge 2.70 MB!
If you place a dozen of the above unformatted photos into your presentation, it can quickly blossom into a 30 MB PowerPoint file. Not exactly easy to move that around by any method, be it email, web, FTP or file downloading service. It also strains your laptop’s processor unnecessarily during projection. If you’ve got the budget for all the best equipment, by all means, but most of us don’t. We need to streamline for efficiency.
So, let’s get practical here and give you some usable information.
For a 4:3 ratio slide, the old standard, I like to use a good resolution of 1280×960 for a full screen photo. It will display superbly and print well for handouts.
For a 16:9 widescreen slide, I tend to use 1920×1080, the average for desktop and boardroom presentations.
But if you need to format an image of a size smaller than full screen you need to calculate dimensions manually. I’ve done that for you on the following two diagrams. If you click on them, they will open in a separate window. Download the image to your desktop, and place it, scaled full size, on a slide within your slide deck. From there you can extrapolate the size of pretty much any photo you need to import into your presentation, without blowing your PowerPoint file size out of the galaxy!
Grid to import photos into 4:3 ratio standard slides
1280×960-grid-for-photo-sizes , click for full size image, then download to your desktop
Grid to import photos into 16:9 ratio widescreen slides
1920×1080-grid-for-photo-sizes , click for full size image, then download to your desktop
Hope this helps in managing your file sizes!
Champagne Design — PowerPoint Design 