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Review: Blackmagic Design Decklink HD Pro, HDLink and Apple 23" Cinema Display


November, 2004


Blackmagic Design Decklink HD Pro, HDLink and Apple 23" Cinema Display


Review by Graeme Nattress

Monitoring solutions for high definition (HD) video, wether it be for 720p or 1080i can get very expensive. CRT based monitoring solutions are pricey indeed, especially when you look at the extreme costs for the optional HD SDI input card. CRT monitors have been the professional choice for monitoring video. However, as the world is moving from standard definition (SD) to high definition, the rules are beginning to change. CRT based HD monitoring solutions are expensive, large, heavy, and don't show the full 1920x1080 pixel resolution of HD (due to the physical limits of CRT technology). One of the great advantages of an HD picture is that you can view it at a much larger size (for instance with a home cinema projector) than you can an SD picture and still have it look great. Making a large CRT is not just prohibitively expensive, but after a certain size, becomes impossible. CRT monitors can display a wider range of colours, but this is not as adventageous as it might appear. For all the reasons above, home HD viewers rarely choose a CRT based solution. Instead, they have the choice of plasma or LCD screens and DLP, LCD or LCOS projection, among others. If you monitor your HD using a CRT monitor, you are most likely not seeing what your audience sees.

The Blackmagic Design ( Decklink HD Pro, HDLink and Apple 23" Cinema Display, work together to provide a relatively affordable LCD monitoring solution that, most importantly, displays the full 1920x1080 HD resolution.

For my work I need to be able to view full resolution HD video in real time. During a collaberative HD project with Panavision we had used a special prototype Sony CRT HD monitor to view 1080p24 HD video. The picture quality was excellent, but I could not see some of the finer details of my work. Even if I could afford a CRT solution, it would not be ideal.

At NAB 2004, Blackmagic Design launched a new box of tricks, the HDLink, which converts HD SDI video into DVI, and was designed with the Apple 23" Cinema Display in mind. Blackmagic Design claim that there is "no higher resolution HDTV monitoring possible". To use the HDLink a HD deck or capture card with HD SDI output is needed. Blackmagic Design make a whole range of Decklink cards which are suitable for use with the HDLink. Since NAB 2004, Apple have updated their Cinema Display LCD monitor lineup to coordinate with the G5's brushed aluminium look. The Cinema Display LCD monitor's connections were also updated to make it much easier to connect to anything other than a Powermac G5 by giving it it's own power supply and hydra-headed umbilical for power, DVI, USB and Firewire, rather than the all-in-one connector from the previous model.

The US$1,999 Apple 23" Cinema Display comes well packaged in a large protective black box. Previous generation Cinema Displays were designed to take their power directly from the Mac. To connect one to a HDLink you need to get a special power supply from Apple. The separate power supply noted above, is therefore a significant advantage for when the new design Cinema Display is to be connected to an HDLink. The new Cinema Display also feels a bit lighter than the original 23" Cinema Display, and has 2 USB and 2 Firewire ports. On the right hand side of the monitor are soft touch buttons for power and brightness. The new brightness controls are particularly useful as they can give an extra degree of calibration for when the monitor is used with a HDLink.

The US$1,995 Decklink HD Pro comes in a small box, barely bigger than a VHS tape. Also in the box is a CD with the driver software and PDF manuals, and a neatly labeled breakout cable. The breakout cable has connectors for serial deck control, world clock out, SPDIF / AES in and out, reference in and three cables for RGB / Y, B-Y & R-Y. All the connectors are black, so some colour wouldn't go amiss here in helping you distinguish which is which, but then again, how often are you going to be changing these connections? The connectors on the Decklink HD Pro card are four BNCs for the 2 dual channel SDI inputs and 2 dual channel SDI outputs, and the multi-pin connector for the breakout cable. The card works for both SD and HD over SDI.

Decklink HD Pro box

HDLink Box

Decklink breakout cable

The US$695 HDLink came in an old style Decklink card box, with stickers to signify that it's really an HDLink inside, and a sticker on the back to tell you to download the latest drivers from the Blackmagic Design website. In an extra box, there was the small power supply for the HDLink. The power supply connected to the HDLink but there was no power cable to plug the power supply into the wall. Given that Blackmagic Design is an Australian company it is perhaps understandable that they would not be able to supply a North American power cord. Fortunately, finding a spare was easy.The HDLink has inputs for single or dual channel SDI, USB to allow the computer to control it, power, DVI out and two RCA connectors for stereo audio. The USB cable needed was not supplied, but again, I quickly found a spare in my cables drawer.

I knew that the Blackmagic Design products don't come supplied with SDI cables, so I had pre-ordered some from my local pro video dealer. Before installing the card I downloaded and installed the latest (4.6) drivers from the Blackmagic Design website.

To say that the install of the Decklink card was tricky is somewhat of an understatement. If you're at all unhappy about working inside your computer, I'd advise getting someone to help you. I've worked inside many Macs and Powermacs over the years, from the "painful to add memory" Quadra 840AV, through to the "how do I get the cover off to add an internal zip drive" Performa 6400. Recently I added a fibre channel card to slot 3 (one of the pair of 100mhz slots) of the G5 dual 2Ghz that forms the centre of my edit suite so that I could connect a 3.5TB Xserve RAID (striped RAID 50). The G5 design is very easy to open up and work inside. Both the instructions and support pages for the Decklink card say it's a touch tricky to install in the top slot - the PCI-X (133mhz) slot of a G5, and it is, but my problems extended beyond that as the metal outer face of the card kept getting stuck behind some of the metallic shielding on the inside of the G5. So what should have taken a few minutes ended up taking nearer an hour, but I can say, that if followed correctly, the instructions do work and the card does fit.


Before installation the G5 is opened up and layed down on it's side  


The Fibre Channel card is already installed in slot 3, and you can clearly see slot 4, where the Decklink will go.  


This is the Decklink HD Pro card itself. It's a compact card for what it does, and looks very well made.  


The Decklink card is in place, but it's stuck on the metal shielding.  


Taking the card back out, you can now see the black plastic connector that has to be slightly bent out of the way for the card to fit, and the metal shielding that was causing the card to not fit correctly.  


The card installed quite easily once I'd got around the shielding. Now, from the outside you can see the Fibre Channel connections to the Xserve RAID and the 4 HD SDI connectors of the Decklink card, and the connector for the breakout cable.  


With everything plugged in, the two fibre channel cables and an HD SDI cable to the HDLink. The main monitor is also a 23" Cinema Display, here connected to the ATI 9800 card in the AGP slot.  


The HDLink, here set up for Dual Link HD SDI. You can also see the power supply for the new style 23" Cinema Display.  


Everything working!  

Once the card was installed, I connected an SDI cable from the Decklink to the HDLink, the DVI connector from the Cinema Display to the HDLink, and the USB from the HDLink to the G5. I plugged in the power for the monitor and the HDLink, switched on the G5, and a short time later the new Cinema Display sprung to life with an extension of the OS X desktop. Firing up FCP HD with the Apple / Panasonic DVCProHD demo footage (distributed at NAB 2004 and included in boxed copies of FCP HD), and setting the video out to the appropriate Decklink setting, the Cinema Display and HDLink presented me with a wonderful, bright, vivid picture. Everything had worked first time - just as it should. Connecting the Cinema Display's USB and Firewire ports to the G5 was a little more tricky given the less than generous length of cable after it splits into it's various connectors, so although it works, it's hard to make it look tidy (see picture 8).

HDLink Control Application

The HDLink's firmware asked to be updated when I launched it's control application. A short time later after the HDLink had been power-cycled I had control over the colour look-up tables that the HDLink uses to convert video to the 10bit RGB values used by the monitor to display the image. The application is simple, but interactive, and allows you to load in custom look-up tables for specialist uses. In use, the HDLink gets a little warm - which is not surprising given the little PowerPC processor in there! The audio outputs worked great, and will ensure that any SDI video monitored through the HDLink will remain in sync with the picture. As well as converting HD SDI to DVI, it will also convert PAL and NTSC SD too - with the option to show pixel for pixel as with the HD inputs, or doubled so that the image fills the screen a little better. The HDLink currently does not support anamorphic SD, so you will see the image appear squashed, rather than stretched to it's proper 16:9 shape.1920x1080 HD nearly fills the Cinema Display leaving only a small black bar top and bottom. 720p footage is left sitting in the middle of the display with a large black area surrounding it. From an accuracy point of view, this is totally correct as the HD is mapped pixel for pixel, but it would be nice to be able to ask the HDLink to "fit-to-frame" for presentation purposes. If you only need 720p HD, it therefore might make more sense to buy the 20" Cinema Display instead for an even more cost effective approach to HD monitoring.

Image size comparison between 1920x1080 and 1280x720 on the 23" display


Decklink HD Pro Video Controls

Decklink HD Pro 3:2 Pulldown and VANC Controls

The Decklink HD Pro card is controlled from a panel in system preferences, where you can set, for instance, 4:2:2 or dual link 4:4:4 output, or SD down conversion of HD on the SDI outputs. When not being used to view video in, say, FCP, the second monitor can act as a desktop extension with the Decklink's Video Desktop feature. This is great, and adds value to the product for when the G5 is not being used for editing. I also tested the card for viewing composites in Motion and Shake. Motion slows down quite a bit when video monitoring is turned on, and Shake worked fine.

I did have an issue with the iSight camera and iChat, where iChat would claim that the camera is being taken by another application which I should quit before I can video chat. I was not using the camera in another application, and a quick response from Blackmagic Design tech support told me it was a bug in iChat where it grabs the first video source it sees, thinking that it's the iChat camera when often it's not. Removing the Decklink Quicktime drivers from the Quicktime Plugins folder and restarting iChat quickly solved the problem. Apple knows of the problem and will hopefully fix it soon.

Photographs to try and show the comparison between the HDLink picture and that of the Digital Cinema Desktop Preview. The digital photos were taken with a Canon Powershot G3. The pictures are not a scientific test, but I think you can see the degree of difference in colour and detail between them. The HDLink picture looks visibly superior.

Without a CRT HD monitor sitting next to the Cinema Display, it's hard to judge how accurate the colour representation is, but I can say with some confidence that it's a lot better than watching HD video on a Cinema Display connected direct to your G5's graphics card and using the new FCP HD feature of Digital Cinema Desktop Preview. The colours also looked very good when compared with a downconvert to my SD CRT monitor. The image is more dynamic than Digital Cinema Desktop Preview - it literally glows off the screen at you, full of life, with wider range of rich, vibrant colours. White actually looked white! The Digital Cinema Desktop Preview also does not seem to display interlaced video as the HDLink does, perhaps contributing to its soft appearance. One major benefit of using the HDLink for displaying DVCProHD footage is the lack of artifacting that is visible compared to when the footage is viewed inside FCP or via the Digital Cinema Desktop Preview mode. Personally I was quite disappointed at the level of artifacting I saw on Apple's big screen demos of the new DVCProHD features in FCP HD at it's NAB launch, especially in shadowy areas of the picture. When viewing via the HDLink I see very little in the way of DVCProHD artifacting, and in particular the 1080i DVCProHD demo footage is stunning to watch via the HDLink. I don't think that the lack of artifacting has been caused by any softening of the picture though. The picture is supremely sharp and detailed, and normal video noise is visible as a fine grain in the picture, without being exaggerated or softened. If you don't have the Apple / Panasonic NAB demo DVD then Blackmagic Design themselves have some DVCProHD 1080i50 demo footage on their site you can download and check out yourself.

Closeup showing the finer detail of the HDLink and its display of interlacing.

Closeup showing lack of interlace display and lack of the finest of detail on the Desktop Cinema Digital Preview.

Although SD does not have the resolution of HD, it plays back with excellent quality through the Decklink and HDLink. I viewed through the HDLink some animated TV specials that were mastered to Quad 2" in the late 70s that I had just done some restoration work on. The pristine digital display is ideal for spotting all kinds of analogue artifacting in the source material and I can certainly see details that I missed in the restoration that I hadn't seen when viewing through my CRT SD monitor. Pristine 10bit DigiBeta footage plays back superbly, with all it's superior detail and lack of compression artifacting readily visible.

Editing in FCP HD with the Decklink HD Pro and HDLink providing monitoring on a 23" Cinema Display.

It would appear that there is currently no single perfect way to view HD for critical monitoring purposes, but for the reasons outlined above, I think that any critical HD monitoring solution should include a full resolution LCD display. The Decklink HD Pro and HDLink is a vital tool in allowing affordable, high quality LCD displays, like Apple's 23" Cinema Display, to be part of my critical HD monitoring solution.


Graeme Nattress was born and grew up in England, but now lives and works in Ottawa, Canada with his wife and daughter, where he researches and develops new and innovative software for video editors. He can be contacted at and you can check out his software developments at

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