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Sony PMW-EX3 Colorimetric and Resolution Assessment

By Akley Olton



Introduction

The PMW-EX3 offers the great features of the of many HD cameras of its day, it features an interchangeable lens system, genlock, timecode and remote control capability for real added flexibility, offering a low-cost HD studio solution.It was the first semi-shoulder camcorder to carry the legendary CineAlta 24P brand with multiple frame rate recording capability such as 59.94i, 50i, and native 23.98P, as well being 1080i/720P switchable.


There is also a choice of a 35Mb/s High Quality mode or a 25Mb/s, HDV 1080i compatible mode. To take advantage of this high performance recording capability, the PMW-EX3 uses and imaging system consisting of three ½-inch type CMOS sensors, each with an effective pixel count of 1920×1080. In addition, there’s a purpose-built interchangeable Fujinon Professional HD ½-inch 14x lens and a unique dual focus ring mechanism. Included in the package is a ½-inch lens adaptor to allow use of other ½-inch lenses, plus the ability to use other optional lens adaptors for 2/3rd-inch, cinema-style and digital SLR lenses.


To maximize recording time, the PMW-EX3 has two memory card slots which means with a pair of 16 GB SxS PRO memory cards, it can record up to 140 minutes of HD footage.

The PMW-EX3 HD compact camcorder was the ideal solution for a wide range of customers from broadcasters through to independent videographers and film makers who want exceptional HD picture quality and state-of-the-art workflow from an affordable semi-shoulder camcorder.However, after a life span of 9 years, the camera seems like a typical HD camcorder, but in its time it was the desired revolutionary choice of many. In saturated camera markets of 2017 lets take a look under the hood to see how she holds up.


Dynamic Range

Minimum exposure is claimed to be F/10 at 2000 lux, with about’ 320 and 640 depending on the curve being used .The picture profiles, offers a choice between a wide variety of gamma curves to flexibly handle contrast and give a specific 'look' to an image. With 8 preset Gamma settings four types of STANDARD gamma curves, and four types of CINE Gamma curves (CINE 1, 2, 3, and 4), which are identical to those of other CineAlta camcorders. Operators can select the best-suited preset gamma curve, depending on scenes.

Standard curves are very high contrast out of the box handles highlights and lows are very well but considerable higher than usual level of noise can be seen. However, these presets can be adjusted to created the desired contrast ration.

With the XDCAM EX MPEG-2 Long-GOP codec the Cinema Gamma or “film-look” setting attempts to mimic a film camera with insufficient tonal range that is required for grading and post-production. However the Cine curves responds very nicely in the highlights at best, when the camera is set the so that the exposure range that drops to 7 stops or less. The differences between the Standard and Cine Gammas are seen in the details of the high lights and saturation, especially in the Reds. Moving from Standard 2 to Cine 2 with the Grey 18 remains in the same place, only the signal is compressed from the mid-tones inwards reducing the contrast of the highlights of the generals image.

Over exposition that exceeds 1.5 stops and the highlights are unrecoverable as the XDCAM EX codec gives a usable range of 3 stops above and 3 stops below the normal expositions, after that we begin to loose details, the image deteriorates and noise increases. Which is perhaps not quite as good as can be achieved in ⅔” cameras. The difference in pixel size in the PMW-EX3 are smaller, so sensitivity is maintained at the expense of highlight handling and video noise.


Colour

The full glory of camera´s processing is an image at 4:2:2 10 bit, which can be capture via the camera´s analogue component video outputs, with digits via IEEE1394 Firewire/iLink in HDV format and full 10-bit HDSDI output to a suitable external recording device, but if you shoot to the XDCAM EX codec the camera uses a 4:2:0 8 bit at 35 Mbps to SxS cards in SP & HQ modes.


Attempts at a film looks are compromised by the 8-bit 4:2:0 recording system. The interpretation of colour in the EX·3 has a very ugly saturation in Standard, while in Cine the colours are less saturated and when exposed properly creates great images technically.

In both the Standard and Cine gammas, there were no true “reds”as the yellow and orange patches were a slightly desaturated and hues shifted towards green, but otherwise there was no single colour error large enough to cause a problem. With an exposure of +2 textures begins to distort and the colours begin to desaturated, while when underexposed any attempt to recover details after -3 stops results in noise and colour saturation especial in the Reds.


Resolution

Horizontal TV Lines show aliasing and blurring need the centre of of the image also, but not enough to cause problems.shows the result for setting progressive, but with the same detail control settings as for interlace.

Horizontal resolution has not changed, there is still light aliasing near 1920, but not enough to cause problems. But vertical resolution has changed significantly, there is now the same depth of modulation at 1080 vertically as there is at 1920 vertically. This level of vertical detail will cause “twittering” when viewed on a classical crt monitor, and may cause some problems in MPEG compression, because high frequency content is not expected to have high amplitudes.

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