I recently bought an older Canon Selphy 4x6 photo printer and I love the thing. It has its flaws - like when it wastes a single image's worth of ink every time you power up the device (Canon, surely you can fix this after how many versions of this printer?). But on the whole, being able to get high quality 4x6 prints at just over 30 cents a print whenever I want, without having to deal with inkjet ink is simply great (it uses 3 color dye sheets).
Maybe I'm old school but I still make prints and still put them in albums - I find them easier to thumb through when I'm looking for that all important picture from days gone by. And prints have always been 4 x 6 (except when they were 3-1/2 x 5 way back when). 4 x 6 matched the old 35mm film (24 mm x 36 mm) format perfectly so nothing was lost. But making a few prints on the Selphy the other day reminded me of how problematic print making can be today.
A funny thing happened when digital cameras started to replace 35mm film. 35mm film had managed to outlive 110, 126, mini-disc, APS and other lesser known rivals. But it couldn't compete with digital. Camera makers were quick to see the greater potential of instant digital image delivery - not just for print making but also for delivery to other spaces such as the living room TV. Almost from the beginning, digital cameras sported video outputs that allowed image playback onto NTSC/PAL screens. These had a 4:3 screen (1.33); they were only slightly wider than they were tall. Early computer monitors also had the same aspect ratio because they were all based on TVs. The old VGA standard was 640 x 480. This was expanded to 1024 x 768 but both still had a ratio of 1.33. Later computer monitors became even more "square" with "workstation" resolutions like 1280 x 1024 (1.25). Ironically, professional photographers like squarish images. Square medium and large format films have been around for a long time. The major advantage of square images is that there's no need to rotate the camera. Cropping is done later in the printing process and any ratio can be achieved there. This works fine for the pros who command the entire photographic chain all the way through the darkroom.
These early digital cameras, mostly of the point-and-shoot (POS) variety, sported 4:3 image sensors. And with good reason - most started out using tiny sensors originally used in movie cameras. Since those were targeted for TV use, everything was 4:3 and it was all just one big happy family. Right? Except of course, the professional digital SLR (dSLR) market continued to use the 3:2 (1.5) aspect ratio of 35mm film. Whether they were called "full frame", "APS-H", "FX", "DX", or "APS-C", Canon and Nikon provided 3:2 (1.5) aspect ratio cameras to fully fill a 4x6 print image. Meanwhile new formats like Four-Thirds from Panasonic & Olympus sought to seek a middle ground - larger than the POS sensor but smaller than the dSLR. They decided on a 4:3 aspect ratio as their name implies.
Having two competing formats is a real PITA when making prints. Most print processors still use 4x6 as their standard image size. When a 4:3 image comes along, they automatically crop the image to fill the entire field to avoid having white space. To fill a 4:3 image onto a 3:2 piece of paper, some of the height of the image (the "3" in 4:3 for a horizontal image) is lost. Anyone who has had head or feet chopped off on a print knows how frustrating that it - you take the time to frame the picture only to have the printer chop it off. Worse still, the widespread ability to digitally edit an image on a computer, including cropping it to any size and aspect ratio, leads to even more potentially chopped prints. Some print houses give you the choice - cropped or uncropped prints. But they usually default to cropped meaning they will fill the frame when necessary.
But there's a bitter irony to the story. At around the same time that digital cameras evolved from the wider 3:2 to the more square 4:3 aspect ratio, the video and computer industry was busy going the other way. Movies have always had a wide field of view and when shown on TV, the sides had to be cropped out. Making the advanced TV standard wide-screen friendly was a top priority. The same thing happened on computer screens. All are now 16:9 (1.77) or wider. So one of the destinations of the 4:3 POS camera was suddenly no longer 4:3. What happens to that pocket camera digital image when it's displayed on a wide-screen? Well chances are it won't be cropped because the TV is able to handle the different incoming signal differences. But wait 'til you try and print that image!
This all seems like a huge missed opportunity to make the lives of the consumer easier. POS cameras continue on their march at 4:3 though most can now take 16:9 HDTV digital movies as well. Many also allow 3:2 picture taking. Meanwhile TVs are getting bigger and staying at 16:9. At the end of the day, it's up to the consumer to be aware of what their cameras are doing and what their prints will look like - but don't expect anyone to warn you of the pitfalls.