2K Monitoring
Posted by Mike McCarthy on November 14th, 2007 filed in Industry StatusThere are much fewer monitoring options if your workflow requires full 2K resolution monitoring. The primary reason for this is that most consumer gear and broadcast equipment all top out at 1920×1080. The HD-SDI and HDMI interfaces are both limited to 1080p in most cases as well. HSDL (High Speed Data Link) is an older standard, developed specifically for transmiting 2K image data over regular BNC cables at HS-SDI frequencies.  AJA’s Xena2Ke and Kona3 cards support HSDL, but HSDL usually runs at 15fps, and is therefore not realtime, and not a useful option for monitoring. Dual link HD-SDI as well as the new 3Gb/s SDI are both capable of 2K, in various forms. Certain products use 3Gb to carry full 1556 line 2K images, but most 2K hardware only supports 2048×1080 resolution over SDI varients.  The other two primary connection options are VGA and Dual Link DVI. VGA has a maximum standard resoultion of 2048×1536, although a fairly rare 2304×1440 is also an option (Sony 24″ CRT). Although perfectly 4×3 (1.33 aspect ratio), 1536 lines of vertical resolution is a little short of the 1556 lines of a standard 4perf full aperture 35mm film scan. For 1.76 and 1.85 aspect ratios (1152 and 1080 vertical), VGA provides full resolution support. Dual-Link DVI supports 2560×1600 when connected to a 30″ LCD, which is more than enough for every variation of 2K. So that leaves us with four ways of driving our display: Dual-Link HD-SDI, 3Gb SDI, VGA, and DL-DVI. Other proprietary methods exist, but will be difficult to incorporate into an Adobe based PC workflow.
Dual-link HD-SDI supports 2K from a variety of sources, specifically the NVidia QuadroFX SDI cards, and Bluefish444 2K|Lust I/O card. The primary display devices that support this signal format are 2K projectors, which makes sense due to the fact that almost all 2K finishing work is targeted towards theatrical projection. Unfortunately a projector precise enough to accurately monitor color at 2K resolution is extremely expensive. Certain high end CRT video monitors also accept this signal, but most of these eventually scale it to their native 1920 maximum horizontal width. Sony’s new BVML230 will accept 2048×1080 inputs, but will scale it to 1920×1080 as well.
3Gb SDI has very little hardware available to support it at this point. The only real solution on the market at this point is to use Blackmagic’s Multibridge to generate it, and Blackmagic’s HDLink Pro to receive it. This solution merely converts it DL-DVI, which we will discuss below. The Multibridge allows fullscreen 2K without depending on the workstation video card. In the future, I expect that this standard will be widely adopted to replace dual-link SDI. This is especially beneficial as we move towards more 4K finishes, which currently require 8 HD-SDI links to support full resolution in realtime.
I am not aware of any solutions allowing 2K to be displayed over VGA besides using software to output the signal from a computer graphics card. Certain older 21-22″ CRT monitors support 2K resolution, but you will need to be able to configure your software and/or your graphics driver to allow you to get fullscreen video output to the monitor.
Dual Link DVI can support 2K, but flat panel LCDs are the only products I am aware of that support this connection interface. This makes it less than ideal for color grading work, but a great solution for visual effects work. The excess resolution removes the need for dedicated full screen output, but that can usually be achieved as well. Both computer graphics cards and the HDLink Pro can output 2K resolution over DL-DVI. Graphics cards are obviously cheaper, and will likely work better in AE, but an HDLink Pro, with the appropriate hardware to drive it, will probably offer better performance in an NLE, like Premiere Pro. It really depends on your budget, but if you can afford dual desktop monitors PLUS a full screen monitor, the HDLink Pro enables this configuration.
So those three interfaces dictate most of your actual display options in that regard. Current 2K projectors are driven by Dual Link SDI, but we will see DL-DVI and 3Gb SDI replacing that in the future. 2K CRT monitors can be driven via VGA connections, and LCD flat panels can support 2K and above using DL-DVI.
Tags: 2K I/O, AJA, Blackmagic, HSDL, Multibridge, Nvidia, Xena
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