Love it or loath it it's something anyone involved in generating 'film' images is going to have to get to grips with some time or other - if they don't retire first

The problem is that there are a bewildering array of digital cameras out there, as well as a vast range of digital formats. And not all come close to being capable of being described as Digital Cinematography cameras - but that's not to say they don't have their uses, just that you need to understand their limitations if you are going to get the best out of them

And along with the camera itself are discussions on workflows, LUTs, data management, on-line editing, grading and Digital Intermediate...

But the one big issue to remember is that shooting for a theatrical product is not the same as shooting for TV... Get that right and most problems will vanish.

The Digital Revolution
The on-going digital revolution in film making brings the mixed blessings of greater variety of production choices than ever before, combined with the need for a greater level of knowledge if things are to go smoothly...

But does Digital Cinematography actually exist?

Promises, promises
Digital Cinematography is something that has been on the cards for years, with many camera manufacturers claiming Digital Cinematography capabilities way before now - and often without any serious 'cinematography' capabilities. Hands up all those who remember Sony's Digital Cinematography claims for DigiBeta! I think I've even got their VHS marketing tape somewhere at home - if I remember rightly, snappily titled 'Digital Cinematography'.

HD makes the right noises
However, the introduction of HD brought with it cameras that were capable of being considered close to, if not truly capable of being called, 'digital cinematography' cameras.

But, the issue initially faced by these cameras was a WYSIWYG approach to image capture, as has been historically the case with all 'video' cameras. The latitude of the captured image being designed for immediate transmission, rather than for later creative post-production, as has been the case with Film captured images since its introduction, some 100 years ago.

Becoming more 'filmic'
The first approach to making these new HD cameras closer to true digital cinematography was to add 'film' profiles to their settings, to give a more filmic image.

However, the first 'film' settings applied by the manufacturers mistakenly attempted to match print film characteristics, rather than film negative; a result of the historic approach by digital camera manufacturers to make the captured image immediately usable.

While based out of Rome's Cinecittà Studios I was lucky (unlucky?) enough to have access to one of the very first Panasonic VariCam cameras with 'cine mode' settings, and was very disappointed with their attempt to emulate print film characteristics, rather than negative film.

Sony then followed with their Gamma Curves, with a selection of downloadable settings that also emulated film print stocks.

How could manufacturers get it so wrong? Print stocks are not used to capture images!

Luckily, Sony also introduced a software program that allowed for user manipulation of the camera settings, and Light Illusion generated a selection of CVP Gamma Curves that matched closely the high dynamic range, low contrast capture techniques of camera negative film, generating a near Log output image (as is the case with camera negative film).

These curves have become something of an industry standard for DoPs using Sony CineAlta cameras.

Manufacturers follow...
As time moved on both Panasonic and Sony introduced modes or settings of their own capable of mimicking the above approach to image capture, and Thomson went one step further with their Viper camera and its Log based FilmStream mode. All later cameras, have continued this approach

Cameras getting ever closer to true digital cinematography capabilities!

Depth-of-Field
However, an outstanding issue for many users of these cameras has been their depth of field, with HD based cameras having 2/3" CCD sensors, so having a deeper depth of field than 35mm film (akin to 16mm film). For many this means the digital images are still too 'video-esk' when compared to 35mm film's shallower depth of field.

But, over the past year the digital cinematography market place has grown significantly, with a number of new cameras being introduced that really can be considered as being Digital Cinematography rather than re-purposed HD video.

High latitude, high dynamic range, low contrast capture has become comparatively commonplace, and many cameras are now using full 35mm aperture sensors (or larger), answering the final question to enable true Digital Cinematography.

Capture Resolutions
Resolutions have also increased, with new data cameras providing 2K, 4K and beyond resolutions. However, resolution is not actually a major issue for many image capture requirements, and I would strongly recommend dynamic range is viewed as being far more of a requirement. More on this below.

More than one option
This means that today we have two main development strands that contain cameras that could be considered as being digital cinematography capable.

2/3" HD sensor based cameras with extended dynamic range capture capabilities; and data cameras with extended dynamic range, some with 35mm sized sensors.

And in between there a selection of cameras that output a HD image signal (and resolution), but have 35mm sized sensors.

In the HD camp, the cameras output/record via a HD video stream at 1920x1080 or 1280x720 resolutions, usually to in-camera tape decks, or external tape recorders, depending on the output format - single link HD or dual link - although they can record to data recorders too if required.

The HD format and recording technique defines the final image quality, with single link being YUV (YCrCb) 4:2:2, with in-camera recording at 1920x1080 resolution commonly being recorded 1440x1080 through pixel reduction, with reduced bit depth from 10 bits to 8 bits, chroma reduction, plus additional DCT based compression. The result is that there is a limit to the amount of dynamic range that can be captured without the introduction of artifacts and/or banding becoming visible.

Other HD cameras record 1280x720, applying a similar level of pixel and bit depth compression when recording, although no often without colour reduction. As a result the final recorded image quality is very similar to that of 1920 based cameras.

Cameras that record only to external tape decks can record 4:4:4 RGB with minimal compression, much like the following data based cameras. The limitation is the format’s HD resolution of 1920x1080.

Data cameras, as would be expected, record to data recorders, some with compression, some without, although this tends to be a user option depending on shooting techniques and the data format and recorder in use.

True data cameras are gaining a lot of market interest, combined with a range of data recorders.

As an aside, the first feature film to be shot 100% via a data workflow, and posted the same way was Silence Becomes You, with which I was heavily involved, and which used Viper and the S.two data recorder.

What all this means is research cameras and workflows based on your project's requirements.

Compare and contrast
many comparative tests have been performed by many people in recent times, including by Light Illusion and members of Geoff Boyle's Cinematography Mailing List (CML), attempting to compare various cameras capabilities.

One thing that does tend to come to the fore is that while all cameras can be rated to have the same mid-exposure, in practice, none are exactly identical, which can cause problems when attempting to rate a camera for shooting under different lighting conditions. The rating of film stock is well documented and well understood.

Such tests tend to be very technical and don't always tell the real story when shooting in real-life conditions with shadows, bright areas and highlights contained within the image at any one given time.

Personally a simple, and I think preferable, way of testing latitude is to take a high dynamic range image, view it through a print LUT, grade it for nominal exposure and then see how much detail is clearly visible within the shadows and highlights through varying the grade. This tells a lot about the capabilities of a given camera.

Reported issues
During testing, and during actual use, there have been a number of issues reported with digital cameras, with some showing highlight artifacts, such as ringing around bright areas of the image; some showing smearing, again most notable around highlights; others having excessively noisy shadow detail; some showing compression or other 'digital' artifacts within the image.

But then film's not a perfect capture medium either...

Understanding the options
When choosing the camera for a specific project it's not just the camera that is important - the workflow required to get from scene-to-screen is equally important, if not more so.

In-camera tape recording is a very simple workflow, but has potential quality issues as mentioned above.

External tape recording will improve quality, but with the need to be tethered to the external recorder.

Uncompressed data recording also required tethering to the external recorder, but offers the best potential quality.

Compressed data recording workflows tend to use wavelet compression across the entire frame, making the quality potential greater than in-camera tape systems using block based compression.

The camera choice tends to be based on the look required, including depth of field and single Bayer chip vs. three chip sensors, as well as the desired resolution.

Resolution as a requirement
One of the big discussion points, and something I've deliberately left until last, is resolution.

I've left it until last as resolution is nowhere as important as dynamic range and depth of field when it comes to making images that can be truthfully call Digital Cinematography.

With 4K and 5K cameras already being available, discussion on higher resolutions is really a moot subject. The human eye just can't see such resolutions, and using the eyes resolving limit of 1.7 arc minute even viewing images on the largest theatre screen sizes produces a theatrical max resolution of approx. 2K, which is damn close to HD...