Aspect ratio is width to height, W:H.
On a full frame 35mm camera the frame size is 3:2 because the actual size of the frame — the exposed area of film or the size of the sensor — is 36mm x 24mm.
Simples!
Except for a dozen other factors.
Cameras with APS-C sensors have the same ratio although their overall image size is smaller. Other cameras may vary, such as 4:3 for Micro Four-Thirds systems, or 54:42 for film cameras that purport to be 4×5. Film cameras using 6×7 film have an 11:9 ratio.
Don’t even get me started on mobile phones! Here, the most popular ratios are 4:3, 3:2, 1:1, 8:5, 5:3, and 16:9. Remember: the sensor size remains the same, so you “lose” pixels if you choose something non-standard.
So which is the best ratio for street photography?
When you process your images you have several options:
- Saving the whole image in the original aspect ratio.
- Cropping to the original ratio, then saving.
- Cropping and saving to a preset image size, such as 4×5/8×10; 5×7; 4×3; 16×9; 16×10; or square. Note that some software (Lightroom, for example) may offer to reduce the size of the image on selected ratios in one operation.
- Cropping to any ratio by dragging the sides of the crop frame to any position, then saving.
- Stitching images together in panoramas, or even 360-degree virtual reality presentations, then saving.
A Free-for-All
Basically, it’s a free-for-all! You can have any aspect ratio you like. There are no limits, no rules. You’re adrift in a sea of creative possibilities.
So which is the best ratio for street photography?
Let me pose the question a different way. Which is the best aspect ratio for YOUR street photography? That’s the question you need to ask.
One option is take the pragmatic route and make the aspect ratio fit the subject. This means cropping each time, often to a different ratio. Is that what you want?
Without some standardisation, a selection of your images will have no commonality of shape. This may not matter in an exhibition if you can afford the customised frames, but in many online galleries it looks a bit haphazard. A little variety of shape is visually interesting; too much is just plain fussy.
Nothing beats display monitors for variety of shape. If you want to get totally confused, try shopping for a new monitor on the Dell website. Here you get a huge choice of monitors with various resolutions and aspect ratios. 1280×1024 (5:4), 1366×768 (16:9), 1440×900 (16:10), 1600×900 (16:9), 1920×1080 (16:9), 1920×1200 (16:10), 2560×1440 (16:9), 3440×1440 (21:9), 3840×2160 (16:9), etc.
I’ll leave you to do the math, but the above aspect ratios are sometimes only an approximation.
Essentially, you should think of your display merely as a desktop — not as some kind of perfect device to which you should tailor your images. That’s a myth that was once encouraged by the perfectionists at Apple Computer who listed “crop to display ratio” as an option in Aperture (remember Aperture?)
Filling the Screen
Of course, it’s great to see your images filling the whole screen, especially if you want to show them on television. If you don’t fill the TV screen you get black bars at the top and bottom or on either side of the picture.
But even TVs are not totally standardised. Older TVs have an aspect ratio of 4:3; whereas high definition (HD) is 16:9. To accommodate movies, some TVs now have a wider screen: 21:9.
So have you made up your mind yet?
It’s tempting to shoot in 3:2 and crop to 16:9, isn’t it?
Except for the fact that technology moves on.
Street photography is for eternity, not for tomorrow’s technological fashion.