I've been giving some thought to aspect ratio. Which ones look good with which kind of scenes or subjects. Which ones are more appealing to the eye. What do you think?
With a few doodles with a ruler and some basic math, I see some patterns emerge. Between a square at 1:1 ratio and a pano at 2:1 ratio I see I could have literally any ratio in between the two. But if I think in terms of extending my square based on simple fractions of the original square a lot of the common ratios emerge.
For example starting with a square and extending it by 1/2, I'm at the common 3:2 ratio, 1.5 to 1. If I go with 1/3 of the original square I'm at the also common 4:3 ratio, 1.33 to 1. Extending the original square by 1/4 I get the 5:4 ratio, 1.25 to 1. I read somewhere this is the most common ratio. Why is that?
I could keep on, but I think 1:1, 3:2, 4:3, and 5:4 cover the most common ratios. If you look at the standard sizes offered by photo printing houses these are there. But even now we can custom print any size, yet these keep going strong.
Just like music, are we attracted to simple fractional subdivisions of the root?
Very thought-provoking questions. I usually pick my aspect ratio based on what looks as "invisible" as possible - not drawing attention to the aspect ratio itself. Maybe this is why I almost never use a square aspect ratio in my photography. It inherently draws attention to the fact that it's a square. This (but to a greater degree) is also why I have never been interested in experimental crops like circular, triangular, etc.
I don't think that people are inherently attracted to simple fractional aspect ratios. I see no reason why a photo with a 3 x 4 aspect ratio would be any more aesthetically compelling than a photo with a 3 x 4.2317 aspect ratio. That said, fractional crops are pretty useful for making prints to match standard paper, matting, and frame sizes. I personally always make sure that my photos are a fractional ratio, but only for this reason and not for some inherent power of exact fractions.
A lot of photographers will keep their photos at a 3 x 2 aspect ratio simply because that's what their camera captures, and therefore it's how they composed the photo in the field. If you carefully compose for one aspect ratio, it probably won't be a good idea to change to a different aspect ratio in post-processing (unless you failed to compose well in the field or are re-evaluating the vision you had in mind).
I find that I keep a majority of my digital photos in 3 x 2 and a majority - actually, all, so far - of my large format film photos in 4 x 5. It's not like I have ethical ojections to changing the aspect ratio in post-processing. It's just that I composed those photos carefully in the field to fit the confines of the frame.
Sometimes I do compose photos knowing that I will change the aspect ratio later. For example, 3 x 2 is a pretty elongated rectangle that I don't always like for vertical photos. I've composed plenty of vertical photos knowing that I will exclude some of the top or bottom of the frame and turn it into a 5x7, 3x4, 4x5, etc., back in Lightroom.
I rarely crop to standard ARs. Rather, I crop to the composition. Form follows function. I have several panos and landscapes that are quite extreme on the long side (well over 3:1). I believe that what counts is what the composition demands.
That said, if the intention is to print and frame (and if $$ are a factor, as they normally are), printing to a standard AR will certainly save considerably on the cost of framing. In that case I've re-cropped to a standard ... in some cases. In other cases, where I've been fond of the composition, I've bit the bullet and printed and framed to nonstandard AR.
I almost always keep my cameras original 3:2 ratio, with very few exception when I don't find a pleasant composition with this ratio, or when I stitch panoramas. The reason is simply that a standardised aspect ratio makes handling images much easiear for most of my applications.
My most used are square for photography and 16:9 for wallpapers/screen displays.
My most used are square for photography and 16:9 for wallpapers/screen displays.
That 16:9 is an interesting one. I believe it came to be because a TV ratio was needed that would encompass the several previous TV ratios without too much black space top/bottom or left/right.
The fractional idea also brings to mind the harmonic armature of the rectangle idea. Where any rectangle can be divided in several directions into 1/2, 1/3, 1/4, 1/5. The points where the lines cross the most supposedly being where the strongest points in a composition would lie. For example the "rule of thirds" is derived from the armature. This was a departure from the classical dynamic symmetry which was based on square roots.
I think it all derives originally from musical harmony, where a string resonates as a whole but also in 1/2, 1/3, 1/4 etc. The half forming an octave, 1/3 a perfect fifth, 1/4 another octave, 1/5 a major third, together forming the major chord, a 3 major chords together the major scale. After this was discovered a lot flowed from it. For example "The music of the spheres" where the planet's were thought to correspond to the simple ratios, and then the harmonic armature of the rectangle.
Of course it all probably became standardized by practical considerations such as what size paper the paper mill would produce and the size of the rolls of paper used in the manufacture of photo printing paper, and what dimensions it could be cut without waste.
@bleirer 16:9 is a cinema/movie format. That is where you get 1920 x 1080 (HD) monitors, and why I prefer to use a 1920 x 1200 monitor because it is closer to 3:2 than 1920 x 1080.
Unless you have a specific format/ratio to fit something, I'd prefer the content over the form. As a rule I only tend to crop vertical photos to less than original 3:2, like portraits around 3:4 as a starting point, unless it's specifically for some stories like 16:9 use. Otherwise I crop a lot regardless, what's best for the photo to leave inside/outside.
Some good comments from others already. I have several perspectives that may be helpful.
I do equestrian event photography and sell images from the events. For a typical event, I do a quick edit so images look their best, and crop roughly to a loose 8x10 or 5x7 aspect ratio. I crop so that the image looks best, but I don't know what size print the buyer will want, so I want to leave room for a range of crops by the buyer. I approve all print orders, and if I find someone has a poorly cropped image or needs more space, I'll replace the image with a very similar crop from the original. 90% of the images purchased by clients have an 8x10 or 5x7 aspect ratio. The exception is large prints, which are often a 3:2 aspect ratio.
I also have judged and curated a gallery for the past 7 years. The images are all from a nature photography association. Images can range from a 16x20 to a 16x24 print with a mat and frame and sometimes smaller variations that fit in frames of those sizes and variations. In this case sticking with standard print sizes is helpful in keeping down the cost of frames and mats. Square prints and panoramas look odd in a gallery that is mainly the specified sizes. My personal preference is a 4:5 aspect ratio for a vertical print and a 3:2 aspect ratio for a horizontal print.
The third area is photos for publication. I want to submit the best possible crop to fit the image, because that image looks best. If a specific size or aspect ratio is needed, I want to know in advance. But sometimes layout drives the crop. In this case, as an editor I want a range of options to fit space available. But its a lot easier to have a full size uncropped image that I can crop to fit the space than something too tight. Loosely cropped also works. But in both cases, I want to be reasonably close to an ideal crop for the image but I have seen editors use some rather extreme crops.
This has an impact on workflow. While I may crop modestly early in my editing workflow, I crop loosely and make a final crop at the end for an intended output. Here there are two reasons. One is allowing latitude for different size prints to be produced for a range of uses. The other is final sharpening and noise reduction can depend on output size, so depending on your editor, output sharpening is always at the end when the final image dimensions and use are known.
Eric Bowles
www.bowlesimages.com
I learned early to keep the "delete cropped pixels" box unchecked in Photoshop.
I used to crop to the composition requirements, but since I've dabbled in printing I now care that the crop I've chosen is one that's available to be printed at an affordable price. So print availability drives my decisions most of the time, unless I'm quite sure I will never want to print it (because it's too low resolution, too cropped in, etc.).
I know the places I print allow a custom size for not much more money. But another option is keep the image to the ratio you like but print larger and either trim the excess yourself or request a trim. There is something to be said for matching the crop to the content and composition.
Aspect ratios like 1:1 (square) work well for symmetrical or centered compositions, while 3:2 and 4:3 are versatile for landscapes, portraits, and general photography.
Wider ratios like 2:1 (panoramic) excel in capturing expansive scenes, creating a dramatic, cinematic feel.
Simpler fractional ratios (e.g., 3:2, 4:3, 5:4) are visually pleasing because they align with natural human perception and balance.
These common ratios persist due to their harmony and compatibility with standard printing and display formats.
Like music, simple fractional subdivisions (e.g., 1/2, 1/3) create a sense of order and appeal, making them timeless choices for composition.