Archive notice: This article was originally published on 18 November 2020 and has been translated into English as part of Digital Production’s archive project.
This article originally appeared in the 01 : 2013 issue of Digital Production.
First and foremost, the video glasses brought onto the market by several manufacturers at favourable prices are intended for entertainment or are recommended for augmented reality. However, the relatively lightweight and versatile model from Zeiss can also be useful for camera operators, and not just for stereo 3D.
The spectrum of possibilities for video glasses ranges from military applications to use in technology (e.g. for repair instructions) to the pure entertainment sector. A distinction must be made between glasses that superimpose additional information on external reality (augmented reality) and those that more or less completely fill the field of vision with film images or computer games. Google has announced the first type of glasses with data overlay under the name “Project Glass” for the mass market as an accessory for smartphones, but these glasses will not be available to developers until early 2013.
At present, the market for low-cost devices is still manageable: glasses are primarily offered for gamers or mobile film enjoyment. However, this report is not about immersion in virtual reality, but about use in film production. This already rules out all glasses that rely on a computer or smartphone for operation, such as the expensive Brother Airscouter or Epson Moverio. We consider glasses that only accept analogue video signals to be outdated. This leaves Sony’s “Personal 3D Viewer” and the “Cinemizer OLED” from Zeiss as far as currently available models are concerned, as the supposedly full HD resolution ST1080 glasses from Silicon Micro Display, which were announced for May 2012, are still not available.
The Sony model offers a high resolution of 1280 x 720 pixels and is supplied with video signals via HDMI. However, it is more of a helmet than a pair of glasses, weighing in at 325 grams, is quite heavy and uncomfortable and also relies on a control unit with a mains power supply, which weighs a further 600 grams. For this reason alone, it is extremely unsuitable for film use and also shields the field of vision so much to the side that you would practically be flying blind. The field of view of the HMD T2 is 45 degrees horizontally and is therefore quite immersive, but unfortunately the edges always remain somewhat blurred even with the best possible (and very critical) positioning of the glasses. The new Cinemizer OLED is a further development of the relatively hapless Cinemizer Plus, which was not very attractive with its flat LCD picture, purely analogue feed and NTSC resolution. Weighing around 120 grams, the glasses can be worn for long periods of time and the control unit with its own rechargeable battery weighs around 90 grams, making it easy to put in your pocket. The field of vision is 30 degrees, which is far too little for immersive experiences, but leaves enough of the surroundings visible for other uses. In addition, the glasses themselves do not shield the field of vision too much; you can still squint quite well next to and especially under the Cinemizer and keep an eye on where you are stepping. For cameramen, there are three main areas of application: controlling stereo 3D during recording, image composition with unusual perspectives in motion and, in general, image control in very bright surroundings.
In stereo 3D mode, the glasses are completely sufficient for use with semi-professional equipment such as the Panasonic AG-3DA1; for complex stereo rigs from the professional sector, it ultimately depends on the needs of the user: The Cinemizer OLED only has a resolution of 870 x 500 pixels. But before you write the device off as inadequate, you have to realise that viewers didn’t get to see much more with previous 3D reproduction methods. Stereo 3D was usually transmitted either side-by-side, top-bottom or line interleaved, and in each case the resolution of the HD format of 1920 x 1080 was halved in one of the two dimensions. Only the new frame-packing process (available with HDMI 1.4) avoids resolution losses. Apart from this, many camera monitors in the professional sector do not have a better resolution, even the touchscreen of a Red in the standard 5-inch version only has 800 x 480 pixels.
The Zeiss glasses process all versions of the 3D signals and display them with very good, albeit somewhat warm colours and brilliant contrasts. The OLED displays represent a huge improvement over the previous model. The visibility of the pixel structure is also reduced compared to an LCD of the same resolution due to the better fill level of OLED. The 3D effect is – within the limits of the limited resolution – excellent, as such glasses naturally achieve a perfect separation of the images without any double contours. The picture quality is not only suitable for assessing the picture composition, but also allows acceptable sharpness control. However, a switchable sharpness display with contour enhancement, as offered by many cameras today, is helpful. In typical applications with a very mobile camera, you will not usually be aiming for too narrow a depth of field anyway.
As you would expect from a leading optical manufacturer, the separate, high-quality eyepieces with a range of -5 to 2 dioptres allow most spectacle wearers to adjust to their own correction values. This is where the advantage of the smaller field of view becomes apparent, as the image is sharp right to the edges and covers an interpupillary distance of between 59 and 69 mm when correctly adjusted. For optimum visualisation, you also need to ensure that the glasses are positioned very precisely vertically. This can usually be achieved with the additional adapters for the nose pad – otherwise there will be annoying colour edges on high-contrast surfaces. The adjustable earpieces allow the correct position to be reliably secured and the glasses do not fall down even when looking downwards. However, they are quite hard and can be a little tight over time. Nevertheless, the wearing comfort is far superior to that of the Sony glasses, which can become downright painful after a while.
Sound control is possible via the supplied earphones, which sound quite usable. When not in use, these can also be removed so that they don’t dangle around annoyingly (there is a clever magnetic holder for this, but it is a little too weak). Professionals will usually work with separate sound recording and control anyway. The video signal is fed to the control and power supply box via a mini HDMI connection, for which an adapter to large plugs is included. However, as this can ultimately be an additional source of errors, it is better to buy a cable that is as flexible as possible with a suitable plug on both sides – the permanently connected cable to the glasses themselves is soft enough. A small belt holder would also be useful. Zeiss does not offer this desirable accessory, but a smartphone case should fit.
Analogue video signals in SD can be processed, resulting in a runtime of around six hours. Digital operation via HDMI consumes significantly more power than analogue operation – around two and a half hours of runtime can be expected, after which a break of around the same duration is required, as the battery cannot be changed by the user (after all, it is only screwed in internally, not glued). Charging is easy via USB. The glasses also accept signals via HDMI, which proved to be problematic in some combinations when we tested digital recorders. All output formats work with the Sony FS-100, as well as almost all progressive formats with the Red Epic and Scarlet, with the exception of the rare 720p24 or -25. However, if you want to use a camera suspended (e.g. close to the ground), you will miss an image reversal function, which is logically not required for the use intended by Zeiss. This means that only cameras with internal image reversal can be considered – unless the manufacturer retrofits this via firmware in order to attract a new target group…
Conclusion
While the limited resolution, narrow field of view and lack of shielding from the environment are unlikely to make games and private cinema on trains or planes entirely happy, the latter in particular is an advantage of the Cinemizer when working with the camera. For direct 3D image control or an untethered camera, there is currently no alternative that requires so little space and weight. The relatively low resolution is largely compensated for by the good eyepieces.
