As I'm learning more and more, directing films is really about making decisions. What kind of performance do you want out of your actors? How do you want to frame up the shot? Do you want to use music in the scene? The list goes on and on. Unfortunately, in my opinion, making these decisions can often be a lot more complicated and confusing than it needs to be.
This is because of the way filmmaking has developed over time. A lot of the methodology and terminology we still use today is based on the way things were done years and years ago. Take for example: the way the 16:9 aspect ratio was developed, the fact that your sound guy will probably still say “speed” to indicate that the sound is recording, and don’t even get me started on the different framerates we’ve been left with thanks to the differences between PAL & NTSC.
The wide variety of different aspect ratios & resolutions used in film & video production are just one of the many areas of filmmaking which can seem frightfully complex and alienating until you get the hang of it. The purpose of this article is to cut through the confusion, and to empower you to make an informed and considered choice when it comes to the final aspect ratio and resolution of your next film project.
(NOTE: This is an updated version of an older article which discussed a wider range of aspect ratios and resolutions. My interest this time is in helping filmmakers working today, hence the omission of aspect ratios like 4:3 which are rarely used in contemporary productions. For information on some of these less popular ratios and resolutions you can check out the older article here.)
WHAT THE HECK IS AN ASPECT RATIO ANYWAY?
When discussing film or video, the term aspect ratio generally refers to the aspect ratio of the entire video/film frame. This may also be called the image aspect ratio. It is a ratio of the width of the image (or video/film frame) by the height of the image. Aspect ratios don’t define the exact width or height, only how the width and height compare to each other.
There are two main schools of thought on the numbers used in this ratio. Some prefer to use only whole numbers, while others prefer to fix the height of the image at 1. This means the same aspect ratio can be described in at least two ways. For example, 4:3 and 1.333:1 are the same. The same goes for 16:9 and 1.78:1.
Over the last hundred years or so, films and videos have been produced in a wide range of different aspect ratios. This article will discuss the most common aspect ratios and resolutions currently in use, namely: 16:9 (which is the current standard for television and web video) as well as 1.85:1 & 2.39:1 (which are currently the standards for theatrical distribution).
OK FINE, BUT WHAT DOES RESOLUTION MEAN?
Generally, the resolution of an image describes the actual dimensions of that image. It can be measured using different units. Back in the old days of analogue video it was measured in lines, and some people still use lines to describe HD resolutions. Despite this, it is probably more useful for most of you to think about video resolutions in terms of pixels. Confusingly there are two different (and contradictory) conventions for describing video resolutions. On the one hand, the HD resolutions popular today are described by their height. On the other hand, resolutions higher than 1080p are currently described using their width. Confused yet? Let me explain.
HIGH DEFINITION RESOLUTIONS
Let's start with HD resolutions. Currently, the term HD generally means either 720p or 1080p. If you're watching a Blu-Ray then you are most likely seeing an image in one of these two resolutions. 720p and 1080p are also becoming more and more popular on websites like YouTube.
720p generally describes a 16:9 video frame that is 720 pixels high and 1280 pixels wide (or, using the traditionalist approach, a 16:9 video frame that is 720 lines high). 1080p generally describes a 16:9 video frame that is 1080 pixels high and 1920 wide (or, using the traditionalist approach, a 16:9 video frame that is 1080 lines high). The “p” stands for progressive, which is a discussion for another time.
Did you notice that I said "generally describes"? The problem with all this is that for this method of description a 16:9 aspect ratio is assumed. But this is not always the case. For example, a resolution of 1920 x 800 is described as 1080p because it has the same 1920 pixel width as 1080p, even though the height is NOT 1080. Like I said in my introduction, this is just one of the many aspects of film production which seems a lot more confusing than it needs to be!
RESOLUTIONS ABOVE HD
As stated above, resolutions higher than 1080p are currently described according to their width. While HD had two standard heights in use (720p and 1080p), there are a variety of resolutions currently vying to be the new standard. The most common resolutions above HD are currently 2k and 4k, although the Red Epic is currently able to shoot 5k, and resolutions as large as 6k and 8k are already being tested and discussed.
The "k" here stands for kilo - a thousand. So at first glance, 2k (meaning two thousand) seems like it should be almost twice as big as 1080p. However 2k describes a video frame that is approximately 2000 pixels wide, not high. So, in reality, 2k is not actually that much bigger than 1080p (which is 1920 pixels wide).
Notice I used the word approximately. For some reason that still eludes me, this method of describing aspect ratios isn’t really accurate. For theatrical distribution, 2k generally describes an image that is 2048 pixels wide instead of the expected 2000 pixels wide.
To make matters worse, there are (at least) two schools of thought on exactly how wide resolutions above HD should be. Films prepared for theatrical distribution have been using the 4k resolution for a while now, while in 2012 the NHK Science & Technology Research Laboratories proposed a different (and lower resolution) 4k that is four times the area of 1080p which is part of their new UHDTV (ultra high definition television standard).
But let's not get too bogged down with these details just yet. I'll outline the common resolutions for each aspect ratio as we go through them.
MAKING AN INFORMED CHOICE
PICKING THE RIGHT ASPECT RATIO
When selecting an aspect ratio for your next film or video project, there are two main issues that need to be considered.
Firstly, how is this film going to be exhibited? Is it a feature film designed for theatrical distribution? If so, then you may be safer going with one of the standard theatrical aspect ratios like 1.85:1 so that your film can be projected as intended without being cropped. On the other hand, if your film is heading for television or web, than using 16:9 probably makes more sense.
The second thing to be considered is a lot more complex. Namely, what aspect ratio will best suit the story you are trying to tell, or the mood you are trying to create with your video. Even though it's important to consider the exhibition method of your project, that doesn't mean it should lock you into a certain choice. Some recent theatrical films have chosen to use 4:3 for artistic reasons, and it's becoming more and more common to see web videos in 2.39:1 in an attempt to make things more cinematic.
At the end of the day, it's a decision to be made by yourself and your director of photography (and maybe the producer and/or studio). A wider aspect ratio like 2.39:1 can make your film or video feel more cinematic (at least partly because it's an aspect ratio we're used to seeing in the theatre) and it can lead to some very dramatic compositions. On the other hand, more moderate aspect ratios like 16:9 or 1.85:1 may lend themselves more to drama as you can focus more on a person's face. The more films you watch, the more you will get a feel for the different ratios and how they can affect the viewer.
FINISHING YOUR FILM IN THE DESIRED ASPECT RATIO
There are a number of ways that the aspect ratio of a finished film or video can be achieved.
Some productions are finished in the "native" aspect ratio that they were shot in. For example, many videos produced for television and web are both shot and finished in the aspect ratio of 16:9.
Other productions are shot in one aspect ratio and then cropped in post so that the final image is in another aspect ratio. For example, I'm shooting my first feature film Play It Safe in 16:9 and then cropping in post to the theatrical standard 1.85:1. I have also shot a couple of music videos in 16:9 and then cropped them in post to 2.39:1 to achieve a more cinematic effect.
Today, it is easier to do this than at any time in film history. Don't let the technical side of all this intimidate you, we'll go through all the details as we go along.
1.78:1 (aka 16:9)
16:9 widescreen (often described verbally as “sixteen nine” or “sixteen by nine”) will be the most important aspect ratio to most readers. It is the standard aspect ratio for the current generation of video display and production. It is the standard aspect ratio for HD video, and it is also used in some feature films (although for theatrical releases it's more likely that the visually similar ratio of 1.85:1 will be used).
Most current televisions are produced with a 16:9 aspect ratios. In late 2008, YouTube embraced this new standard and widened it’s player (which had previously used the 4:3 aspect ratio). A number of computer monitors (including ones produced by Apple) also use this aspect ratio, while others use 16:10 (which is just a little bit taller). All this is important to know if you want your videos to look good to the maximum number of people. If your video uses a different aspect ratio it’s more than likely that either pillarboxes or letterboxes will be inserted alongside your video. If you use a ratio that is not as wide as 16:9 (usually 4:3) then pillarboxes (vertical black bars) will be inserted to the left and right of your video. If you use a ratio that is not as tall as 16:9 then letterboxes (horizontal black bars) will be inserted to the top and bottom of your video. This is not necessarily a big deal, but it’s worth thinking about. If you want to use the maximum amount of space on most people’s televisions, computer screens, and YouTube players, then 16:9 is the aspect ratio for you.
Here are the standard resolutions currently being used for the 16:9 aspect ratio:
|720p||1280 x 720|
|1080p||1920 x 1080|
|2k||2048 x 1152|
|3k||3072 x 1728|
|4k||4096 x 2304|
|UHDTV 4k||3840 x 2160|
|UHDTV 8k||7680 x 4320|
As you can see, there are quite a few different standard resolutions that can be used with this aspect ratio. If you're aiming to create something to be viewed on TV or the web today then 1080p is probably what you're going to use. However, if you can afford to shoot on something like the Red Epic or Scarlet and you want to future proof your video, than finishing in UHDTV 4k is not a bad idea.
If you have the resources it can be a good idea to create a master of your film project at the highest resolution available. That master can then be scaled down for distribution in different channels. For example, if you have the facilities to shoot and edit at 4k it would be good to export a final master file at that resolution. This can then be converted to either 70mm or 35mm film for theatre projection. It can also be exported to 4k or 2k for digital theatre projection, 1080p for television, blu-ray, and web viewing (although YouTube can now support resolutions of up to 4k), and even smaller for DVD. It is much better to start big and then scale down. Starting small and then attempting to scale your film up is problematic and can yield some pretty ugly results.
Along with 2.39:1, 1.85:1 is one of the most common aspect ratios used in commercial cinemas. 1.85:1 and 16:9 are very similar in appearance. As 16:9 is the standard aspect ratio for HD video, 1.85:1 is rarely used outside of shooting or preparing a film for theatrical release.
(A 1.85 image letterboxed within a 16:9 frame.)
Currently, there are not many cameras around that shoot footage natively in this resolution, so the most straightforward way to prepare your digital film for theatrical release in 1.85:1 is to shoot in 16:9 and then crop the frame size in post. This can easily be done using software such as Final Cut Pro 7. To achieve this in Final Cut, simply drop your footage into a standard 16:9 sequence, bring up sequence settings (command+0), and set a custom frame size.
For Play It Safe, we are shooting in 16:9 1920 x 1080p, and we will probably end up finishing our master at either 1080p 1.85 (1920 x 1038) or Digital Cinema 2k 1.85 (1998 x 1080).
Here are the current standard resolutions for this aspect ratio:
|1080p||1920 x 1038|
|Digital Cinema 2k||1998 x 1080|
|Digital Cinema 4k||3996 x 2160|
For DVD releases, there seems to be two schools of thought regarding this aspect ratio. Some films are cropped to 16:9 from their original aspect ratio to fill an entire 16:9 television. Other films retain the aspect ratio with very small letterboxes at the top and bottom which are not even visible to most people who have their TV set to "16:9 overscan" mode without even knowing it. In either case the final output resolution is the same as the letterboxes are part of the final video file created.
(A 2.4 image letterboxed within a 16:9 frame.)
And here comes perhaps the most confusing & beautiful aspect ratio of them all. This seems to be more like a category of ratios these days, as the aspect ratios of 2.4:1, 2.39:1 and 2.35:1 are all used and are considered to be pretty much the same thing. Depending on which variation you use, you will get a slightly different resolution but the differences will be very slight. From what I can tell, videos designed for the web and Blu-Ray seem to be finished in the ratio of 2.4:1, whereas for digital cinema the aspect ratio is closer to 2.39:1.
At the end of the day, they all look pretty much the same so my advice would be to stick with whatever format you're outputting to. If you're going to web or BD, I'd use 1920 x 800 which is 2.4:1, but if it's theatrical it's probably better to stick with 2.39:1 which is the digital cinema standard.
These resolutions can be achieved in a number of ways. As with 1.85:1, the most common and straightforward method currently available involves cropping a standard 16:9 image. This can easily be done in post using software such as Final Cut Pro 7. To achieve this in Final Cut, simply drop your footage into a standard 16:9 sequence, bring up sequence settings (command+0), and set a custom frame size. This will cut off the top and bottom of each shot. You can then move each shot up or down to adjust framing as you desire.
However, some newer cameras can natively capture a frame size with this aspect ratio. For example, the Red Epic and Red One MX can capture footage in this aspect ratio in 5k or 4.5k respectively.
Let's take a look at the standard resolutions being used with this aspect ratio:
|1080p||1920 x 800|
|Digital Cinema 2k||2048 x 858|
|Digital Cinema 4k||4096 x 1714|
|Red 4.5k (2.33:1)||4480 x 1920|
|Red 5k (2.39:1)||5120 x 2134|
If I was shooting in either of the two Red resolutions I would most likely finish in the Digital Cinema 4k resolution as it is the standard for theatrical projection.
Again, for DVD release films in this resolution will either be cropped to 16:9 or released in their native ratio with letterboxes.
Now that you (hopefully) understand more about the most common aspect ratios and resolutions used in film and video you can make a more informed choice for your next project (or maybe avoid some headaches in post). Different aspect ratios will suit different projects so get to know the aesthetic affects of each one and choose whatever works best.
I will endeavour to update this article as other aspect ratios and resolutions come into common use. If I’ve made any errors with my definitions etc, please let me know and I will fix them up asap. If you enjoyed the article or have any questions please leave a comment below.