In the last tutorial we looked at the various types of photo printers that are available, and mentioned the ideal image sizes for printing on different sizes of photo paper. This week we'll have a look at optimising images for printing, and also a couple ideas for improving presentation.
As I mentioned in the previous article, there is a slight problem when it comes to printing photos from your digital camera on any of the standard photo paper sizes. The majority of digital cameras shoot pictures with a standard aspect ratio of 4:3, the proportions of a traditional domestic TV or computer monitor. More and more cameras are coming along that can shoot in 16:9 format, suitable for wide-screen TVs and monitors, and some can shoot in the 3:2 aspect ratio of 35mm film and 6 x 4in snapshot print paper, but if there's a camera out there that can shoot in the 1.4142:1 ratio of international paper sizes then I've never seen it.
What this means is that if you print your digital photos on A5, A4 or A3 paper (or even larger if you happen to have a grand to spend) then you either have to crop the picture or trim the paper. Most printer utilities (the software that comes with the printer) have an option to squeeze or stretch the image so that it fits onto the page, but this is not a good solution since it alters the proportions of the image. The software may also automatically crop or resize the image to fit, but again this is best avoided, since you will often have no control over the process, and the image re-sizing algorithm in the printer software may not be very good. It's a far better idea to manually crop and resize the image yourself in your image editor, that way you get to decide exactly which bits get chopped off. There are several ways to do this.