What is HD?

'High definition' (HD) is a very general term used to describe cameras, editing equipment, lenses, transmission and recording formats. The one common element is that HD offers the promise of higher quality than standard definition. There are many HD recording and transmission formats with different resolutions and frame rates. There are no standards for HD lenses, or standards for compression. For instance, a low resolution standard definition image can be upconverted to an HD signal and then forever more be correctly termed a HD picture. So sometimes HD is less than it should be.

Film can be transferred to HD for editing?

Yes a so called 'HD production' could be shot on film and promoted as a HD or digital production. The term HD is also being loosely used to describe the upcoming range of 2k and 4k digital motion picture cameras.

What is the difference between a HD camera and a Digital Cinema Camera?

In general..marketing.

Do You Need Less Light When You Shoot HD?

In controlled situations you will use the same number of lights, as with film. In uncontrolled, low light situations it is possible to utilize available light more effectively than on 35 mm film. This is because there is much greater depth of field with HD format than 35 mm film. This is solely to do with the small size of the HD sensor, not any shortcoming in the sensitivity of film. For modest production budgets on HD an acceptable depth of field can be utilized using ambient street light with the addition of a few key and back lights on the subject. But if shooting outdoors the amount of light needed to balance sunlight is the same, if not more on HD as film. So although it is possible to pick up a HD camera, switch it on and record a picture, without careful lighting the result can be nothing more than HD home movies. the ride frame grab

Do You Need Less Crew with HD?

If you need a image for a large screen presentation that is steady and sharp you must use a 35 mm style crew (retrained to use a digital camera). The same goes for TV drama work. It is possible to work with less crew but you will be limited in your range of shots. For instance an operator with an assistant and director can shoot general views. But pulling focus by relying on the viewfinder is difficult.

HD Tapes Can be Damaged by X-rays or Metal Detectors

HD tapes are perfectly safe being transported through airport security scanners and X-ray machines. The HD recording is more difficult to erase than Digibeta or Beta SP. A metal detector is thousands of times less powerful than what is required to damage a HD tape. Even a hand-held metal detector, passing directly over a tape, will not damage it.

HD CCDs Are Damaged by Airline Travel

Anecdotal evidence suggests that gamma rays will damage pixels in camcorders. It seems that if a camera is going to have a problem, it has it on its first or second flight. If it survives its first few flights then the ccd seems not to be affected by subsequent flights. This has been the case with standard definition cameras in the past few years where less than 1% of cameras have been found on delivery (or shortly after) to have 'dead' pixels. However an early model HD camera in the space shuttle has lost many pixels perhaps due to its prolonged exposure to gamma rays. One must be vigilant if the camera is new.

How Good is the Audio Recording on an HD Camcorder?

Better than DAT. Four channels can be available with an adapter on a camcorder.

Do I Use a Clapper with HD?

If the cast and crew are feeling 'clapper withdrawal symptoms' then yes, even if you are recording sound on camera. However the continuity person should make a note of time code regardless of whether the clapper is used or not. The director and editor are far more likely to refer to time code than clapper. A producer should consider that introducing HD, like any new technology challenging an established profession, is more to do with people and jobs than pixels and compression.

What is Negative Fill?

Negative fill is achieved by blocking out ambient light from the subject. As CCDs respond well in the shadows it is not uncommon on location to use negative fill to darken one side of the subject to create modeling.

Is There a Difference in Lighting for HD Rather than Film or SD?

HD 'sees' more detail than standard definition (SD) especially in the shadows. It is possible to exploit this with subtle lighting. On the other hand, highlights burn out more readily than film so the DoP must be careful to control highlights, through makeup, filtration, post-production techniques and careful control of lighting. Some lighting effects do not work at all in HD. High key is particularly difficult. A combination of lighting and post effects should be explored to create your look.

Do I Need a Big HD Monitor to Make Good HD Pictures?

An inexperienced DoP or operator will need a good monitor. Makeup, props, director and gaffer love the big monitor in a studio as it allows them to do their job more efficiently and effectively, especially on limited budgets. If the 24 inch monitor is impractical a 14 inch CRT monitor will give a reliable idea of focus, gamma, highlight and shadow detail. A 9 inch monitor is a good representation of colour and gamma. However it is pointless using the monitor for critical evaluation unless the DoP is under a black cloth or the monitor is in a dark room. And don't forget to remove your sunglasses.

A range of HD LCD and TFT displays are being released that offer good resolution and will be suitable for checking focus and examining detail. They are unlikely to be suitable to aid fine control of lighting or adjusting the colorimetry or gamma of the camera. However, as they are less bulky and cost less than heavy HD CRT monitors they will become popular.

Do HD Cameras Have a Problem with Red?

Panavision cameras have a different IR (infrared filter) than is installed at the factory by Sony. This means more infrared light hits the CCDs. This has led to some confusion that there is a problem with non-Panavised cameras. Sunset

Why Shoot HD If There Is No HD Transmission?

For the same reason we prefer to use 35 mm film rather than 16 mm for TV. The improved quality of the 35 mm format can be seen even on an SD transmission. The same applies to HD. There is greater degree of manipulation in post-production, i.e. reframing. The benefits of a high resolution, low noise image are also apparent when encoding to DVD. If operated in progressive mode HD cameras capture motion in a way that is similar to the film look. HD transmission is available in USA, Japan Australia and in a limited fashion in Europe. HD quality distribution to large screen or HD flat screen is becoming increasingly common across a wide range of industries beyond broadcasting.

HD is expensive.

HD is more expensive than other television formats.

A f900 with two lenses can be rented for £3000 /$5000 per week,

Basic HD online for £1500 per day

HD dubs to digibeta for £90

HD tape is £30 for 50 minutes

Can HD Record in Slow Motion?

The limit for a camcorder at the moment is Varicam 60 fps at 1220x720. A 1920x1080 60i recording can be deinterlaced and turned into a 60p recording at the cost of lowering the resolution. Ikegami have demonstrated a true 120fps 720p camera that uses a hard disk to record the images. A 1920x1080 camera running at 60p is available from Thomson and Sony where a seperate recorder is needed. There is a range of digital super slo mo cameras using single chip imagers of up to 2k resolution, that are capable of up to 3000 frames per second. The images, usually totaling two or three thousand frames are stored in RAM, then downloaded. See my Slo mo reels and frame grab of 60i deinterlaced to 60p Horse race

Video Lenses Are Inferior to Film Lenses

Second generation HD lenses and primes are superior to 35 mm lenses in just about every way. As the size of the image plane is much smaller than 35 mm all the resolving power has to be fine-tuned into a small image plane, so both mechanically and optically they are technically superior to 35 mm lenses. Second and third generation HD lenses are now available that virtually eliminate breathing and are adequate for TV and feature work. More expensive zooms and primes should be considered if budget permits. Look at these HD frame grabs taken with a standard def lens.

Panavision Lenses Are Best

No one to date has done the side by side test, but Fuji's new Super zooms T1.6 are as fast as the big Panavision lenses. In respect of prime lenses, Zeiss and Fuji have superb glass and Canon have a new set of primes. Panavision have adapted their lenses to B4 mount

Should I Record Sound on Camera?

Definitely. You will be able to start your digitizing immediately. On tight budgets a post-production supervisor can schedule the offline or online independently of any sound work. On tight budgets it is possible to do a rough cut with sync and including basic track laying in the offline. Once the pictures are locked all audio channels can be lifted from the online for the sound dub. Expect more audio track laying to take place in the offline as onlines are becoming more audio feature rich.

What About the Adapters that Convert 35mm Lenses to HD?

There are two types of options. The Angenieux adapter is 200 mm in length and is T1.6 and inverts the image, which can be corrected with appropriate additional hardware of a f900 or at the flick of a switch on the Varicam. The other options utilize a fast spinning or vibrating ground glass where the image from the 35 mm lens is focused. The image from the ground glass is re-photographed to fit the smaller HD sensor. The result is a soft look with texture. These systems typically reduce effective aperture by one and a half stops.

Does HD Strobe More than Film?

No. It captures motion in a very similar way. Some people get disturbed watching the monitor when the camera is being set up and often panned around very quickly. This is not something you see watching film dailies of course. Also if watching a pan on a monitor from a distance the edges of frame can take your attention rather than the subject. Next time you are at the cinema watch the edges of frame not the subject during a pan and you will see strobing. A camera operator who is new to video will need time to acclimatize to an HD viewfinder. More details about judder here

Film Guys Can't Handle HD!

Some old dogs will learn new tricks, others will not. An alternative to expecting a DoP who has never shot video simply to adapt and cope is to have a video operator or a DoP who has worked on HD as part of the crew. At the moment there are not enough experienced HD hands [en] so get whoever you can to help.

Can Video Guys Shoot HD?

A 'video guy' will know how the camera works and have a sensitivity toward CCDs' limited contrast range. He will be able to troubleshoot any problems and not make silly mistakes. However, he may not have experience in framing for a big screen or working with a focus puller. In the United States there has been very little drama shot on video whereas in other parts of the world electronic cinematography has existed using Digibeta for many years. An 'Electronic Cinematography' set up is similar to film, with film style lenses focus pullers etc.

Should I Shoot Straight and Achieve the Look I Want in Post?

If you don't know video very well then don't play around with the camera. If you are after a full range of tones, don't play around with the camera (although this may be something of a generalization). However, even some simple adjustments in camera will start to manipulate the image in a creative and powerful way. You can communicate this look to the rest of the team via the monitor so the collaborative process is efficient and focused. This is very powerful. especially on tight budgets where departments may not have had all the time and resources to plan and communicate their ideas.see HD grading

Film DoPs who are used to getting the look they want in post are amongst the strongest voices against HD. Some have said they would ban a big HD monitor on set. Other DoPs will realize that they may not always get to the grade, so shooting with an in-camera look gives more authorship than just shooting straight. If the director doesn't like the in-camera look, he or she can have their chance to say so during the shoot. However, beware of very strong looks where the image cannot be pulled back in post. This is a battle for creative control between the DoP, the post house and savvy directors with a background in Photoshop!

Can HD Cameras Handle Extremes of Temperatures and Humidity?

Video cameras love the cold as they have inbuilt 40 watt heaters. They are more susceptible to heat, but the crew are more likely to keel over before the camera fails. However, humidity is always an issue with tape-based recorders. There are humidity sensors that shut the camera down before the tape gets too sticky. A well-versed HD or video crew know what precautions to take in humid conditions.

HD Post Is Complicated and Time-consuming

A well set up HD production will compress a production schedule: trailers etc. can be extracted at any time; audio recorded along with the picture is a great feature for tight deadlines or low budgets; shooting 25p in Europe simplifies the post route.

Audiences Think HD Is Awful

There is no evidence to suggest that a cinema audience can even see a difference between film-originated material and HD-originated material transferred to film! The contrast ratio of projected film prints is the same, regardless of whether the image originated on 35 mm, HD or DV. However, it is becoming clear from the United States that audiences prefer digital projection to film projection. Multiplexes with digital projectors make more money.

What is a Viper?

A Viper is an HD camera head. That is, an HD camera without a built-in recorder. The Viper can output an HD signal to either an HD disc recorder or to an HD tape recorder. The Viper can also output a non-TV format-based HD picture, 4:4:4. On location this signal is recorded on a hard disc or to HDCAMSR and is the highest quality HD picture available at the moment. Also the Viper is the only HD camera that can record full height (1080) lines cinemascope aspect ratio pictures. Note that the Sony f950 camera can also output 4:4:4

What is 4:4:4?

It indicates that there has been no sampling of the imager and no reduction of colours or luminance details before recording. This equates to slightly richer pictures, more scope in grading and fewer artifacts, a very important improvement for bluescreen. However note that on the Sony HDCAMSR format a 4:4:4 image is compressed 4.2:1 during recording.

What is 720p?

720p is one of the many digital TV standards. The picture is made up of 1280x720 pixels with a frame rate of 60p. It is a transmission standard as well in the United States Panasonic use this standard for their Varicam camcorder. Bear in mind that in the same way that HDCAM samples 1920x1080 pixels to 1440x1080, so does DVCPRO-HD compress1280x720 to 960x720.

HD Is Lower Resolution than 2K

When some people talk of 2K they refer to a half 2K scan of an Academy frame. A 2K scan of Academy is actually 1828x1332. HD is usually 1920x1080.

HD post is complicated and time consuming

A well setup HD production will compress a production schedule and is faster than a film route. Trailers ect can be extracted at any time, audio recorded along with the picture is a great feature. Don't shoot at 23.98 if you are editing in PAL

You cannot key a HD picture unless it was recorded on a hard disc.

No doubt it is easier to key an HD picture from a uncompressed recording but test for yourself with a non-linear editing suite. Do this test at a couple of companies and at least one that does not have a telecine suite!

Doesn't 3:1:1 or 4:2:2 sampling throw away lots of important colour information?

Yes and No. Try this test. Connect a HD camera to a large monitor and look at the live picture. Record the scene. Replay and look at the scene off tape. Note the differences. Can you see any differences? Can you even see that the picture you are watching is a replay and not live? However, a computer will see a difference when you try to key. Not all compression is bad, but it does has the potential to bite and certainly cascading compression has a severe impact. Essentiall the clour of one pixel is replaced by the colour of the pixel next to it.

Are HD Viewfinders Awful?

Yes they certainly are! They display only half to two-thirds the resolution that the camera records. Although the black-and-white CRT tube is scanned at HD resolution it does not seem possible to cram any more phosphors into a 2 inch CRT tube. New displays will be released that promise full resolution colour pictures in a small package using new display technology, but gee I originally wrote this in 2003 and still no sign!

HD Cameras Make a Lot of Noise

They are a little noisier than film cameras. Note that the internal fan on some camcorders can be programmed to switch itself off during a take.

What are Dalsa, Kinetta and Arri D20 cameras?

These are new cameras that use single chip CMOS or CCD sensors. This enables use of existing film style lenses and optical viewfinders. The Dalsa camera has a 4046x2048k CCD sensor, the Arri D20, designed for TV applications is 2880 x2160 CMOS. The Kinetta may have a interchangeable sensor. These cameras use Bayer style filters. On camera recording systems are in development. The comparison between single chip cameras and 3 chip cameras is not straight forward, see what is a bayer filter

What is RED?

Red is another single chip camera under development by Jim Jannard of Oakely sunglasses fame. Jim has significant experience in marketing sales manufacturing and working with new technologies as well as significant interest in motion picture technology. He is not the only manufacturer to combine new sensor technolgy with compression of the bayer signal to create a small and low cost high resolution camera using hard drives as the recording medium. Vision Research has made such a camera as has Silicon Imaging, it is just that the RED marketing is better! In the week of NAB 2006 where plans for the camera were unveiled the Oakley share price went up over $200m.

What is a Bayer filter?

A bayer filter is a colour filter array in a checkerboard pattern that is placed over a single chip ccd or cmos imager to create a colour image. 50% of the pixels are filtered green, 25% red, and 25% blue.  Averaged together, a Bayer chip misses up to 67% of the color information in the image. This isn't as bad as it sounds. Complex calculations from surrounding pixels are made to interpolate the missing colors at each pixel.  However the actual detail is more difficult to "guess" and can result in artifacts or softness. 

Bayer pattern color cameras do not produce equivalent resolution to 3 chip sensors.

So a 4k or 2k Bayer chip may have 3k and 1.5k resolution respectively. This puts the resolution similar to or better than 1920x1080 4:2:2 or 4:4:4 recording. Careful testing of these cameras should be undertaken for blue or greenscreen applications.

Is Visually lossless same as uncompressed?

No. The issue is if visually lossless remains visully lossless through the entire production chain. Uncompressed in theory retains camera original quality through multiple generations.

What is a Clone?

A clone is an exact replication of the original signal. The term "copy" denotes a method of duplication where the data is uncompressed and recompressed (in the case of tape to tape copies) So a copy of a HDCAM image gets sampled and compressed twice. Not good.

The SDTI transfer of data from HDCAM or DVCPROHD is same as making a duplicate of a computer file and this can be called a clone. The data is simply copied from one machine to another, without converting to a TV picture then re compressing which makes it second generation and noiser and softer. No tmany duplication houses have sdti boards in their machines. You must stipulate sdti to get a clone.

It is also possible to get camera original quality by transfering to 4:2:2 uncompressed NLE and storing on hard drives. FIrewire based formats, HDV and DVCPROHD and Infinity have the benifit of camera original quality as standard.

What is HDV?

HDV is a recording standard aimed at consumers. It uses DV style compression, to record a so called HD picture. The recording has less data than a normal DV recording and uses 60 to 1 compression.

Should I go "Native"?

There are many HD cameras, made for live TV that use with imagers that can only scan at 59.97i or 60i. Manufacturers add conversion boards to the base station or to the ccu to convert the frame rate from 59.97 or 60i to 24p, 30p or 720p. Technically speaking this is much less desirable than altering the scanning rate of the ccd or cmos. Native frame rate is the rate which the sensor is being scanned, which is not necessarily what is being output to a vtr.

"Native" is now also being loosely used in post production to describe uncompressed images in "native codec" of HDCAM or DVCPROHD.

Can I shoot in cinemascope aspect ratio?

There are number of ways to achieve a cinemascope aspect ratio image to the audience.

The Viper camera has a ccd structure that enables full 1920x1080 HD resolution in cinemascope aspect ratio using existing lenses. For other 2/3 inch cameras with 16x9 aspect ratio ccds we can use a Canon relay lens that fits between lens and camera. This relays the 2.35:1 middle portion of the image only and optically "squashes" into the 16x9 sensor.

The third method is to crop the 16x9 image in post production. This results in a drop in active lines from 1080 to 700. This was the method used in "Star Wars Attack of the Clones".

Should I use a Film or cine gamma curves in the camera if transferring to film?

It not essential to use special gamma curves in the camera. The ccds themselves have a fixed dynamic range. Film curves allocate more in camera "processing" to highlights at the expense of other parts of the picture. It is far better to control the image through lighting and exposure. However modest gains can be achieved if careful calibration between camera gamma and post is orchestrated.

Does Apple's Final Cut ProHD edit DVCPROHD in "native" mode?

If the image has been imported from the firewire output of the DVCPROHD VTR it exists in the computer, as it did on tape in "native" mode. One can perform a (cuts only) conform by using time code and not having to uncompress the image. This then, is a "lossless" procedure. However, once a mix or any effect is undertaken the data has to be uncompressed and losses occur.

Is HD equipment reliable?

Based on previous experience, a new camera, recording format or post production tools are generally not bug free or fully developed when first sold.

Digital Effects Are Expensive?

Not all digital effects are expensive. Simple effects such as split screen, cloning, locked-off blue screen are low-cost effects in the HD environment. In fact these effects can be previewed and explored in an offline. For instance, bracketing exposure on a locked-off general view is a valuable tool to capture a contrasty scene. However, as a general rule if the camera moves then the cost of these simple effects can become prohibitive, especially to low budget productions. The director and DoP should have a clear idea before the shoot as to what is available in post-production. Standard def 4 pass moco shots

HD Cameras Are Large and Heavy?

They can be configured with accessories that make them look like a Christmas tree! A camera 42 inches in length is possible. However, lower quality, lighter and smaller HD camcorders are available in a 20 inch package. Part of the size and weight is sometimes due to large, fast lenses.

Can I shoot 720p for a 1080 delivery?

Yes. But bear in mind your camera actually only records 960x720 pixels which then have to be scaled up to 1920x1080 for transmission. I am not a fan of the 720 format for 1080 delivery or transfer to 35mm film. In most cases you are paying for a 1920x1080 4:2:2 edit at one end, HD lenses good crew and good subject at the other, but use less than the best imager and recorder in the middle!

Is There an HD Minicam?

HD minicams are very slowly being introduced but there is a good range of box style cameras available. The Iconix is the first true minicam being marketed.

The early models looked rather soft to me.

What Are the Benefits of Shooting HD?

Offers an alternative shooting regime in respect to stock costs.

All takes are available in the edit.

Confidence that the set can be struck, now!

Creative collaboration on set between departments when using an HD monitor.

Fast post-production route.

No penalty for multiple takes, creative freedom of exploring performances.

Generally faster lighting and shooting with a small crew.

Offers greater depth of field in low light situations.

Technical problems can be caught on set quickly.

Back-up camera can be used as second unit for the cost of tape and operator.

Digital is easy to transport distribute immediately the picture is captured

What Are the Drawbacks of Shooting HD?

Less contrast range than film.

Slightly Less resolution than 35 mm film.

New on-set disciplines need to be learnt.

Minimum depth of field is greater than 35 mm film.

Often there are cables connected to camera.

Slightly restricted range of colours, different colour response than film.

Back-up camera is expensive.

Shortage of crews with HD experience.

HD viewfinders are poor.

Post-production routes are still being established.

Conflicting advice, rapidly evolving equipment and software.

Where do I find reliable source of advice?

There are so many perspectives on HD combined with scores of ways of shooting in general and a multitude of delivery criteria that make it impossible to collate anything but a collection of facts which you have to use to make an informed decision. What you can do is be circumspect of advice from manufacturers and facility houses. Use your eyes, but remeber to ask the resolution of the display you are watching. Asking advice from those that have done something similar to your project is a reasonable idea.

What Is the Most Important Thing to Consider When Shooting HD?

The script.