An Outline of the Popular HDCAM Format and Product Range

HDCAMOf all HD tape-based formats, HDCAM is the most popular for worldwide Broadcast HD acquisition. It records 1440x1080 to tape (camera captures 1920x1080), is capable of extremely filmic image quality with 25p recording modes and cine-gamma and the cameras are made by Sony so controls are instantly recognisable to camera operators.

Cine AltaThe format has a product range which can shoot at all of the international frame rates, including the universally popular 25p and 24p progressive modes. The most popular unit in Europe has been the Sony HDW-750P which shoots in 25p ‘film look’ and 50i ‘interlaced TV look’ and was superseded in 2007 by the Sony HDW-790P which can shoot at the same frame rates as HDW-750P but with superior performance. The old HDW-F900H was also replaced by the lighter HDW-F900R as the standard unit for shooting in all frame rates for either Europe or US markets and including 24p.

Although there is a significant price difference between the HDW-790P and HDW-F900R, many claim that the performance of both camcorders at 25fps is the same – this is because they are basically the same camcorder!

Other cameras exist including HDW-730S (now discontinued) which is not capable of 25p ‘film look’ and only shoots in TV-look interlaced modes in 50i and also 59.94i for the US. Also, in the US only, the HDW-750 and HDW-790 (note no P on the end – confusingly, these cameras only shoot in 59.94i interlaced mode only and should NOT be confused with the HDW-750P and HDW-790P available in Europe)

HDW-790P vs. HDW-F900R HDCAM Camcorder

It used to be that the HDW-750P and HDW-F900 had important differences and it was easy to distinguish these units apart.

HDW 790PThe latest 3rd generation offerings from Sony are such that there is very little to choose between them for all projects shot at a European frame rate, i.e. 25p and 50i. However, if you need to shoot at either 24p or a US HD format (29.97p and 59.94i), then only the HDW-F900R is suitable.

If your experience is only the old HDW-F900, then be prepared for a smaller (same size as the HDW-750P and HDW-790), lighter, more power-frugal unit, which really delivers cracking results!

Better still, if you have a DoP who insists on one model over another – arrange a test shoot with both camcorders and see if anyone can tell the difference!

Saying all of the above, we are still told by some DoPs that Sony manage to squeeze a bit more out of the F900R and that this is the preferred camera when comparing a camera model (budget aside). They do however perfectly match in a multi-camera environment.

With the trusted Sony brand name, the interface is logical and robust and the cameras are amongst the most reliable in its class. As the cliché goes, “it does what it says on the tin”

POST PRODUCTION

JH3_GThe Sony JH3 is the perfect machine for off-line viewing and digitising, since it permits playback of HD material with real-time HD and standard definition outputs.

Firewire has become a commonly used data transfer format capable of enhanced workflow benefits for off-line and on-line editing.

All HD formats are capable of using low-cost firewire-based edit suites for off-line purposes but only DVCPro is capable of firewire post-production during the HD on-line phase. The JH3 is no exception to this, so playback of HDCAM material will give a real-time simultaneous down-converted firewire signal in colour with identical time code and sync sound – this is compatible with all fire-wire capable edit systems, which interprets this as DV encoded material.

Important to mention that you CANNOT output native HD pictures shot in HDCAM using firewire, as it works in standard definition firewire mode only.

Down conversion Copies

Whilst HD recordings are entirely incompatible with SD equipment, all HD VTRs provide standard definition outputs, which are compatible with PAL monitors, AVIDs and other equipment. As such, it is not necessary to make down-conversion DV copies of HD rushes in order to load them into an AVID or Final Cut Pro (FCP). It is actually more efficient to load each HD reel into an appropriate HD VTR and digitise each reel in Standard Definition as the VTRs down-convert in real time whilst you play back.

There is no argument for making down conversion copies because it cycles the masters less: In fact by digitising rushes a reel at a time, each reel is cycled only once – the same as making off-line copies, only it costs you less money!

VTRs for down-conversion playback

All HD VTRs of all formats permit standard definition output of HD material in real-time. This is of course frame-rate dependent, since if you are shooting at an unusual frame rate, such as 24 fps, there is no equivalent SD format at this speed. This is further justification for shooting at 25 fps – it saves money and hassle, since you never need to make down conversion copies but can digitise directly from the HD tapes into a SD off-line.

Firewire Edit

Firewire has long been used for SD DV production. The merits of using firewire are clear. HDV or equivalent camcorders compress footage by 30 times so that it takes only a small amount of space for storage. The HD firewire cable then transfers the actual data off the tape without expanding it, to keep the data throughput small. The edit system actually works with the same data as is recorded onto tape, so that you are actually editing cloned camera footage. When you record the images back to tape again, the same data is cloned once more.

Without the additional compression/expansion and other digital circuitry to colour and distort the images, the camera rushes are theoretically unchanged (digital clone) by the process and since the data rates used are quite low, computer hardware and storage can also be a fairly basic and low cost – this makes the whole process very cheap!

HDCAM can only work with firewire for off-line purposes and it is fully compatible with both AVID Xpress pro and FCP as well as non-firewire workstations. The important consideration is that you must originate in 25 fps in HD to produce a PAL firewire off-line version. 24p master material however will automatically down-convert to the US NTSC standard and this will further complicate the edit process (since the time-code will be different in the converted version, so you have 2 x sets of time-code).

HD FIREWIRE AND HDCAM

The bad news is that HDCAM only permits HD post production in an uncompressed format (HD-SDI) and the firewire output, although used with formats such as DVCPro HD, is not capable with firewire when using HDCAM.

HD POST PRODUCTION

Having made a standard definition off-line, you will then need to finish your programme in an HD suite equipped with HD-SDI input (such as AVID Nitris or Final Cut Pro with Black Magic card etc) to conform from the original HDCAM tapes in HD quality, to produce an HD master edit. Delivery is usually made to HDCAM SR for its excellent multi-format capability.

 

Barry Bassett,
Managing Director, VMI December 2008

 

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