why are aspect ratios for digital and analog photography different? (4:3 vs. 3:2 respectively.)?

Answer 1

Digital cameras got started with the idea that the pics would primarily be displayed on computer monitors. At the time 4:3 was the only aspect ratio for computer monitors (and for TV's). Apparently nobody bothered the ask the 35mm camera engineers...

35mm cameras were off in their own world with 3:2. Other format cameras exist with different aspect ratios, but they never got widespread popularity with consumers, like 35mm did.

Now the 4:3 digitals are replacing 35mm for consumers, but we still have to wrestle with the change in aspects.

When we get pics professionally printed they automatically cut 1/4 in. off the top and bottom of the 4:3 digital image to make a 6x4 in. print. What if you don't want to lose the top and bottom? Print them yourself, I guess. But the 6x4.5 prints don't fit in photo albums!

Many digicams give you an option to record in 3:2, so at least you are framing what you will get printed. That seems to be the best you can do right now.

Enjoy...

Answer 2

A frame of 35mm film is 35mm wide by 24mm high (without the sprocket holes.) This is roughly 3:2.
The sensors in all digital compact cameras and dSLR cameras that I know of also have a 3:2 ratio.
My Nikon D200 dSLR has 3872 x 2592 pixels = 3:2 and the sensor measures 23.6 x 15.8mm = 3:2
If you're used to 4:3, something else is going on. Probably the image is cropped when making prints.

Answer 3

many of the digital sensors are APS sized or smaller. If you want full 35mm aspect ratio then by a Canon 5D or 1Ds Mark II. Both have full sized sensors.