An introduction to filmmaking and technology? Sounds like a survey course taken at a local community college, in other words it sounds boring, but I urge you not to dismiss it for I feel it’s important, especially for those wanting to learn and get the most out of the discussion that will transpire over the next year or so. I’m writing this as a sort of guide that can be referred back to should you find yourself becoming lost in the future.
This post therefore will always be easily located in the main menu section of my site under the name “Film & Technology Glossary”. This post will also be updated periodically so be sure to check back from time to time.
So, without further adieu here we go.
High Definition Resolution
Today we live in a largely HD or High Definition world. High Definition mainly refers to the number of pixels that are able to be displayed by our modern displays or TVs. This pixel count is also referred to as a display’s resolution, in HD’s case that resolution is 1,920 x 1,080 or 1,920 pixels across by 1,080 pixels tall. This resolution is most commonly known as HD though in professional circles it is sometimes referred to as 2K -as in 2,000 pixels across (though not really).
There is more to an HD image than mere resolution. Color, contrast and compression also play a large role in HD’s perceived image quality, which I’ll talk about in a minute.
4K is an existing cinema format though it is beginning to emerge in the home markets. 4K is the next evolutionary step over HD; possessing far greater resolution than HD with over 4,000 pixels across by over 2,000 pixels in height. In professional circles 4K generally accepted to have a resolution of 4,096 x 2,160. Because cinema formats often change aspect ratios depending on the type or types of lenses used, cinema 4K is a bit of a moving target with regards to its end resolution. However, to combat this issue, the consumer market as embraced 4K in a more stable format known as Quad Full HD or QFHD.
QFHD, or 4 times the resolution of HD, is still technically 4K despite not possessing 4,000 horizontal pixels as per the standard. However, QFHD does conform or scale cleanly to our current 16:9 aspect ratio, which is a good thing given how many 16:9 displays are currently in existence around the world. But, like with HD before it, there is more to 4K than just resolution.
Aspect ratio refers to the proportional relationship an image has between its width and height. Modern HDTVs employ what is known as a 16:9 aspect ratio, which is almost a perfect fit the widescreen cinema standard known as 1.85:1. Now, you may have noticed that when you watch some films on your HDTV there are still black bars top and bottom. This is because the film you are watching was filmed using anamorphic lenses, which give it a (roughly) 2.35:1 aspect ratio.
The reason our home 4K standard will most likely be QFHD opposed to true cinema 4K has to do with our love of the 16:9 aspect ratio.
Anamorphic refers to a type of lens that is often used in filming that results in a wider aspect ratio than 1.85:1 or 16:9. Anamorphic lenses “squeeze” a wider image onto a standard 35mm frame through the use of special optics. When viewed improperly this “squeeze” results in the action on screen appearing taller or “stretched”. In the home markets or when viewed on a 16:9 display, anamorphic content will appear with black bars top and bottom.
The study of color dates back to the 20′s and to experiments performed by W. David Wright and John Guild. From their experiments the CIE XYZ color space was derived in 1931. CIE XYZ refers to the total spectrum of color visible to the human eye and is often depicted in a sort of triangular graphic.
All subsequent color spaces, such as those used by your HDTV or computer monitor, are derived from the CIE XYZ “triangle” so to speak. With regards to HD (remember there is more to high definition than pure resolution) its color space, often referred to as Rec. 709, is much smaller than CIE XYZ -about a third the size. With regards to your computer monitor (provided you can set it to Adobe RGB) you’re seeing more color than your HD display despite the two potentially having the same resolution. This is but one of the factors that contributes to an image appearing “better” to our eyes.
With regards to cinema 4K, its color space is actually CIE XYZ. Meaning, in its cinema form, 4K should display the entire range of human perceivable color. Currently, it is not known if QFHD will support the CIE XYZ color space or if it will merely retain HD’s color space and only improve resolution as there is yet no consumer or home 4K standard.
Bit Depth refers to the number of unique colors in an image’s color palette in terms of the number of 1′s and 0′s or “bits” used to determine each color. For example, many digitally acquired images are captured in what is known as 8-bit color; 8-bit meaning a total of 256 possible color combinations (28) for each of the primary colors -red, green and blue. Since each primary color has 256 different combinations you then multiply them together to get the total number of displayable colors, which in this case would equal 16,777,216 (256 x 256 x 256 = 16,777,216).
Bringing this back to a reality that is more easily understood, our current HD standard calls for 8-bit color, therefore it is capable of displaying just under 17 million colors. This is also what is known as true color, though it is NOT the total number of colors some formats or displays are capable of showcasing. 4K’s standard (at the cinema level) calls for 12-bit color, which breaks out to over 68 billion colors!
Again, all of these factors contribute to what we perceive as better with regards to overall image quality.
Compression is a tool used to fit large amounts of data into a smaller space. With regards to film compression is a necessary evil for without it no one would get to watch anything digitally for the files would simply be too large for any modern player to play them back. .MP4, .MP3, .M4V, .JPG are just a few examples of compressed file formats that we use in our daily life. Each work a little different from their respected counterparts, though all endeavor to achieve the same end result -to make your digital entertainment, movie, music or image, more accessible.
Where compression gets to be an issue is when it becomes too invasive, thus destroying the fidelity of the image or sound. Examples of this can be seen in streaming video content such as videos viewed via YouTube or Netflix. Compression formats change and every year get better, making once impossible feats now possible.
From a filmmaking standpoint it is important to apply as little compression to the image at capture as possible in order to preserve the utmost image quality downstream. Compression can always be applied to an image or file but not always removed (if ever). Compression has become a hot topic among today’s DSLR filmmakers for many DSLR cameras record in HD via an already compressed format such as MP4. This fact has given rise to a new crop of cameras, such as the Blackmagic Cinema Camera, that are capable of capturing moving images in what is known as RAW -or an otherwise uncompressed format. These cameras can best match the image quality of analog 35mm film when properly implemented.
Workflow means exactly that, the flow in which work happens. In filmmaking this means the path the performance takes from actor to camera to editing and so on. Depending on your chosen tools or medium this process can be incredibly simple or excruciatingly difficult -dare I say painful at times.
For example, a film captured in RAW will have a vastly different workflow than a film captured in .MP4. RAW generally means larger file sizes, greater storage needs and computing prowess when compared to the already compressed .MP4 files (Can you see how it all starts to come together now?) What workflow works best for you and your film will greatly depend upon your budget, camera choice and final delivery format or formats.
Preproduction refers to any length of time before a film begins filming. Preproduction is the time in which most of the planning for the film occurs. During preproduction crews are hired, locations are scouted and locked, actors are cast etc. The idea behind preproduction is simple, to get everything in order to ensure a smooth production.
Production refers to the length of time that a film requires to be -well -filmed. Production can range from mere days to even years as was the case with films such as The Lord of the Rings or Matrix Trilogies as they were filmed, largely, back-to-back.
Post production refers to the length of time following production when the captured footage is edited, altered or enhanced in order to make it ready for exhibition. During this time sound editing also takes place as well as any and all visual effects, though in this day and age it’s not uncommon for visual effects to begin in preproduction.