HD Production Choices

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

Interlace Scan

  • Interlace scanning operates in the same manner as Standard Definition
  • field 1 scans the odd lines of the image
  • field 2 scans the even lines of the image
  • The eye briefly retains the image from field 1, blending it with the image from field 2. We perceive a complete frame as a result.
  • The high flicker rate of two fields in succession produces smoother motion reproduction than 24fps
  • Interlace scanning is used by several HD recording formats for origination and post-production, and by broadcasters for transmission
  • 1080i refers to images that have 1080 x 1920 pixels, scanned using the interlace method

Progressive Scan

  • Each progressive frame is created by sequentially scanning each line of the image from top to bottom to create a complete picture
  • Every frame is a unique image, in much the same way that each frame of film is a unique image
  • Progressive scan frames at 24fps are a contributing factor in creating a cinematic look
  • Progressive scanning is used by several HD recording formats for origination and post-production and by some broadcasters for transmission
  • 720P refers to images that have 1280 x 720 pixels, scanned using the progressive method
  • 1080P refers to images that have 1920 x 1080 pixels, scanned using the progressive method

HD Frame Rates and Frequency

Frame rates available

  • 23.976 (23.98)
  • 24
  • 25
  • 29.97
  • 30
  • 59.9460
  • Frequencies available

    • 59.94 Hz
    • 60 Hz
    • 50 Hz
  • Commonly used frame rates for production

    • 1080 59.94i
    • 1080 23.98p
    • 1080 24p
    • 720 60p

    1080 options (progressive)

    • 1080 23.98p
    • 1080 24p
    • 1080 25p
    • 1080 29.97p
    • 1080 30p
    • 1080 60p
    • 1080 options (interlace)
    • 1080 50i (50 Hz)
    • 1080 59.94i (59.94 Hz)
    • 1080 60i (60 Hz)

    720 options (progressive)

    • 720 24p
    • 720 25p
    • 720 30p
    • 720 59.94p
    • 720 60p

    24p v.s. 23.98p

    24p

    • 24p is referred to as a “Universal Mastering Format” due to it’s flexibility
    • Shooting in 24p produces a similar look to film for motion rendition, since the frame rate matches film
    • Ideal format for film transfers, as film and HD frames match one for one on the tape
    • 24p is NOT a delivery format. After creating your 24p master, you will dub it to create your delivery formats.
    • 24p is considered the Universal Mastering Format, as it is easy to convert to all broadcaster frame rate delivery requirements (25, 29.97, 59.94)
    • 24p is ideal for creating film outs to 35mm for theatrical projection

    23.98p

    • A speed reduction of 0.1% has been applied
    • 2/3 sequence is added to produce 1080i or 720p versions
    • If a film out is required, a “pull-up” is necessary by increasing the speed by 0.1%
    • 24p, 23.98p, 1080i and 720p can be easily down-converted to NTSC for viewing DVDs, if required

    For more information about frame rates and frequencies, or a quote, please contact Mark Wood (mark@studiopost.com) or Bill Hamilton (bill@studiopost.com).

    HD Broadcasts

    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

    Compression

    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)

    Pros

    • record onto smaller tapes; use less tape
    • Use less hard drive space on editing computer
    • Smaller files to manage and export = edit computer working faster

    Cons

    • Picture artifacts increase with higher compression
    • Picture degradation
    • Some generation loss occurs with multiple dubbing or editing processes

    For more information about video compression, or a quote for a HD project, please contact Steve Nichols (steve@studiopost.com).

    Audio

    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

    For more information about HD audio, or a quote, please contact Mark Wood (mark@studiopost.com) or Bill Hamilton (bill@studiopost.com).

    Comments are closed.