Is HD becoming easier?
High Definition is constantly evolving, just as Standard Definition did. Computers are getting smarter, faster, and cheaper, and more HD options are becoming available to producers. Frame sizes are ever increasing as technology is improved. Education about the costs, processes, benefits, and challenges of working in HD is essential, prior to making the decision to work in HD.
Producing HD material for the web is becoming easier. Consumer’s internet bandwidth is increasing, and with high quality video codecs like H.264 and MPEG-4 in common use, more and more sites are capable of providing HD video for clients. Already, sites like YouTube and Vimeo have support for HD video at full resolution (1920×1080).
The Keys to Success
- CAREFULLY EXAMINE YOUR DELIVERABLE REQUIREMENTS!
- Know your budget
- Decide on your artistic approach (frame rates & formats)
- Research the options
Consult with a post-production facility early on to discuss workflow. A streamlined workflow can save thousands of dollars when working within the constrains of a budget.
Is HD always suitable for a project?
The short answer is: HD isn’t always suitable for every project. If the budget doesn’t allow for some increase in costs, other options could be considered.
- If deliverables do not specify HD, and there is no other re-sale value to the project, why incur the extra costs of creating an HD final master? If delivering in SD or on the web, HD is not always the most cost-effective choice.
- If your deliverables do not specify a 24p master, careful re-examination of the time and extra expense needed to create a 24p master based on future needs is in order.
What recording formats can I use?
- Film – the original High Definition format
- Voodoo/Genesis – Uncompressed HD (1200 Mb/s 1:1 compression)
- Sony HDCam SR (880/440 Mb/s, 4:4:4/4:2:2, 4.2/2.7:1 compression)
- Panasonic D5 HD (360 Mb/s, 4:2:2, 4:1 compression)
- Sony HDCam (188 Mb/s, 4:2:2, 4.4:1 compression)
- Panasonic DVCPro HD (100 Mb/s, 4:2:2, 6.7: compression)
- JVC D9 HD (100 Mb/s, 7:1 compression)
- HDV (25 Mb/s, 4:2:0, 60:1 compression)
- RED video(up to 4096 x 2304 resolution, 4:2:2, up to 12:1 compression)
- …more on the way
HD Picture Sizes
Two common picture sizes are used for HD:
- 1280 x 720 (921,600 pixels per frame)
- 1920 x 1080 (2,073,600 pixels per frame)
In comparison to SD:
- NTSC has only 720 x 486 (349,920 pixels per frame)
- PAL has only 768 x 576 (442,368 pixels per frame)
As you can see, it takes many more pixels to fill a frame of HD video than it does to fill a frame of SD. Consequently, HD video takes up much more disk space than SD video. This should be taken into consideration when planning storage for a HD project.
HD Aspect Ratio
All HD formats are 16:9 (1.78:1) aspect ratio.
- Theatrical films may have an aspect ratio of 1.85:1, 2.35:1, or 2.40:1
- Some HD camera viewfinders can display film aspect ratios within the 16:9 frame, when framing for theatrical releases
- Most HD cameras can display 4:3 frame lines within the 16:9 frame
- Used when framing safe for 4:3 full-screen transmission
- Likely to be less of an issue as sales of 16:9 sets increase
Aspect Ratio Conversion
Down-conversion choices from HD to SD include:
- letter-box (black bars top and bottom of image)
- Anamorphic (tall & skinny)
- full-screen centre cut (Lose 20% of left and right of image)
- pan and scan
- See our Understanding Aspect Ratio page for a better explanation.
Interlace Scan Vs. Progressive Scan
HD Frame Rates and Frequency
24p v.s. 23.98p
Broadcast HD is either:
- 1080i (1920 x 1080)
- 720p (1280 x 720)
Broadcasters will specify which format is required for delivery. Requirements for effects work or digital intermediates, and film out to 35mm also dictate frame rate.
HD Color Sample Rates
Colour sample rates refer to the ratio of colour samples to luminance (B+W picture detail) samples
- 4:2:0 – Good 4:2:0 – Suitable for acquisition on small format HD cameras
- 4:2:2 – Better 4:2:2 – Suitable for HD television deliverables
- 4:4:4 – Best 4:4:4 – Desirable for DI Work & Film out
One frame of HD contains 6 times more information (data) than a frame of standard definition
No common tape formats can record the large quantity of data associated with uncompressed HD
Uncompressed recording of HD usually involves hard drives for data storage
HD video data is compressed to reduce the amount of information needed for recording, therefore reducing the amount of storage space required
The lower the data rate (Mb/s) of a tape format, the more compression is required to record HD
Compression can affect picture quality
Various methods are used to compress picture (e.g. MPEG variations)
For more information about video compression, or a quote for a HD project, please contact Steve Nichols (email@example.com).
HD tape formats have between 4 and 12 digital sound tracks, depending on the format
HD broadcasts are capable of 5.1 surround sound!
- Master tapes and delivery tapes may therefore have multiple sound track versions or mixes
- This may affect the selection of format