What is… Aspect Ratio?

I haven’t written one of these posts for quite some time so I thought it about time to put that right. Always wondered what aspect ratio is? Here’s your answer…

Aspect ratio is the relationship between the width and height of the image on screen. It is represented by two numbers separated by a colon – the first number is the width of the screen, the second is the height. An example is 4:3, where for every 4 inches (or centimetres or whatever) wide an image was, it would be 3 inches high.

You may also see 4:3 written as 1.33:1, which is just purely stylistic. If the second number is a ‘1’ then some people like to drop it completely, so it would just be 1.33, again just for stylistic reasons.


When films first started to be made, they were done so in the above ratio, 4:3, as they were 4 perforations high on a film reel. This altered slightly when sound was introduced onto the reel, making the ratio 1.37:1 rather than 1.33:1. In 1932, this ratio was officially approved by the The Academy, and therefore pretty much the whole of popular film making, and thus was known as the Academy Ratio.

In this famous clip from Casablanca you’ll notice the black bars on either side of the frame, a feature of 4:3 aspect ratio.

The Introduction of Widescreen

Cinema was the be all and end all until televisions started to become a more staple fixture in people’s homes in the 1950s. This made the film studios nervous and they looked for something new to keep the punters coming in.

1952 saw the development of Cinerama which used an aspect ratio of 2.59:1 and need three cameras and three projectors to display the picture on a curved screen. As you might imagine, this wasn’t particularly practical. CinemaScope was another widescreen development with a slightly more narrow 2.35:1 and used only the single camera and projector.

Stanley Kubrick’s 2001: A Space Odyssey was filmed in widescreen 2.2:1 – you can see the black bars at the top and bottom of the screen rather than the sides.

When widescreen films were shown on TV (which back then was 4:3 only), the picture either had to be chopped at the sides or squashed down to fit it all in, the latter producing big black bars at the top and bottom, known as letterboxing. Interestingly, when 2001 was first screened on TV by the BBC in the 1980s, they bizarrely inserted fake ‘stars’ on the black bars to fill in the gaps during the outer space sections as they thought audiences would be confused that the picture didn’t fill the whole screen. The effect was apparently very cheap and looked like someone had painted them on.

A technique was also developed called ‘pan and scan’ in which the manufacturer decided which was the most important part of each shot and showed only that, lopping off parts either side. A ‘centre cut’ was also sometimes used, which only showed the middle part of the widescreen image.

Studios started to try and push what they could do, with MGM using 2.76:1 on 70mm film (twice the size of the regular 35mm film) for Ben Hur.

Getting creative

As with many aspects of cinema, directors decided to manipulate aspect ratio for stylistic purposes and used it as a vital part of the film. One of the most recent and effective examples of this is Wes Anderson’s The Grand Budapest HotelAnderson presented the film in three different aspect ratios, each indicating a different time period.

The film starts off with a prologue displayed in the, now regular, 1.85:1.

Tom Wilkinson in The Grand Budapest Hotel For scenes in the 1960s, Anderson then shifts the aspect ratio to a widescreen format of 2.35:1

F. Murray Abraham and Jude Law in The Grand Budapest Hotel

It then changes again to the Academy Ratio of 1.37:1, and it’s in this ratio that most of the film is displayed.


Interestingly, the change in aspect ratio indicates a journey back in time through cinema, moving from modern day back to how films used to be shown back in the day. Not that I’m old enough to remember that. Even more interesting is that Anderson (or perhaps the studio, or both) actually sent a set of instructions to cinemas about how to properly display the film.

A list of instructions from Wes Anderson about how to properly show The Grand Budapest HotelThe change and use of aspect ratios is something that is constantly in flux. The use of IMAX has changed this again, especially when certain scenes in a film are filmed in the format and other aren’t, with it switching part way through. Some filmmakers for both cinema and TV also employ what’s known as ‘shoot and protect’ where they ensure the most important parts of the scene are shot in the middle so that as little as possible is lost should the aspect ratio not convert to different size screens – from cinema to TV, for instance.

Do you have any opinions on aspect ratio? Prefer one over another? Couldn’t give a flying film reel? Drop me a comment and let me know. If you want to read more in the ‘What is…?’ series, click here.

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24 thoughts on “What is… Aspect Ratio?

  1. vinnieh says:

    Glad to see the return of these posts.

  2. Stu says:

    Interesting stuff mate. Personally I’ve always preferred widescreen! Mark Kermode was reviewing a film the other week (can’t remember the name) which starts off at 4:3 or similar before one of the characters actually pushes the sides of the frame out, as if to create breathing space. I like the way Anderson used the different ratios too.

  3. What used to annoy me was when TV would pan and scan movies; drove me crazy. Very interesting article mate, glad that you’re doing these again.

  4. jackdeth72 says:

    Solid Letterbox fan here, Terry.

    Very good stuff indeed!

    If you would like a neat little test bed in framing. And the annoyance of what’s in a scene and what’s left out. Try the subterranean sewer scenes from ‘The Third Man’. Quinlan’s entrance and his later bullying of locals in ‘Touch of Evil’. Or Omar Sharif’s Saharan entrance in ‘Lawrence of Arabia’.


  5. ruth says:

    Glad to see the series back Chris! I’ve always preferred widescreen, though IMAX is always a treat. In fact, I’m seeing Furious 7 on IMAX tonight 😉

    • Widesreen definitely seems the format of choice and I agree! I’ve only ever seen 1 film in IMAX as the nearest screen was a pain to get to but a new one is opening next month literally 2 minutes from my house. Can’t wait!

  6. Great post, man! Definitely prefer widescreen.

  7. Ivan says:

    Great post! I’ve always preferred widescreen!

  8. I definitely prefer widescreen, especially for big event films and I set up my home theater projector screen at 2.35:1 aspect ratio.. I wish more films could be shot in 70mm at aspect ratio of 2.20:1 though, I love the look of Lawrence of Arabia, 2001: A Space Odyssey and a bunch of films from that era of early widescreen. I do love the more vertical aspect ratio of IMAX, since the screen is so tall, the 1.43:1 actually looks better than the widescreen version when view on a true IMAX theater.

    Ever since The Dark Knight came out, seems more directors like to play with aspect ratio switching and now that digital IMAX are becoming popular, we see some movies going the 1.90:1 aspect rout. For example SKYFALL and OBLIVION were shown at that aspect ratio when they were playing at 70mm and Digital IMAX theaters. This summer JURASSIC WORLD will be shown at aspect ratio of 2.00:1. I remember that PROMETHEUS was shown in three aspect ratios when it came out in theater; 2.00:1 for 70mm IMAX, 1.90:1 for Digital IMAX and 2.39:1 at regular theaters.

  9. Excellent post Chris. Love Anderson’s use of aspect ratio in Grand Budapest – very interesting to hear that they actually sent out instructions to the cinemas.

  10. I LOVE your “What is…” posts! This is another great addition to the series, for sure. I actually just shot in 2.35:1 for the first time. It was so crazy how much it affected my framing and compositions. It doesn’t seem like that big of a difference, but once you’re trying to set up a shot, you see how restricting (and, at the same time, freeing) that ratio really is. SO good on you for highlighting it here!

  11. I love these posts! I didn’t know that about 2001 on the BBC. That’s hilarious!

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