SOLID STATE HD RECORDERS

 

Solid State HD Recorders

The popularity of the solid state HD recorder has been steadily increasing as form, functionality, recording quality and options have improved, enabling productions to choose from a range of formats and recording Codecs suitable to their projects.

This range of choice extends from Digital Cinema capture devices such as the  Cinedeck, Gemini and CODEX recorders, which can operate in uncompressed and RAW ingests where ultimate quality and maximum data retention is the goal, to the more prosaic PIX 240, NanoFlash and Ki Pro mini units that fulfil minimum broadcast standards whilst maintaining a more pragmatic ‘real world’ approach to file size and subsequent data management. See our complete range of solid state external recorders here.

Given that solid state acquisition is still a ‘leap of faith’ for some producers used to storing their rushes as a physical entity (tape or XDCam disc for example), VMI rigorously examine and test any new device before allowing it to become part of the rental fleet and with no particular affiliations to manufacturers, we are totally impartial in our assessment of the suitability and practicality of any device in a working environment.

Solid State recorders offer a solution to two distinct acquisition requirements:

The first being the ability to record uncompressed (or only loosely compressed) data streams from high-end cameras such as the Arri Alexa to maximise the sensor output and quality for cinema exhibition and  wide colour gamut spacing for CGI green screen applications. Typically, this need to preserve the ultimate quality output is filled by the CODEX, CINEDECK and just arriving, GEMINI units that can operate with a wide range of Codec support- ARRIRAW, UNCOMPRESSED RGB, CINEFORM and PRORES 4:2:2, whilst maintaining support for logarithmic dynamic range encoding such as Arri Log C and Sony S Log. Generally these machines record to SSD drives that are either bespoke to the unit or generic types.

The second fulfils the necessity to raise a natively lower spec camera to broadcast standards by using the 1.5GB or dual link 3GB HDSDI output from the bnc connection (such as the Sony F3). The KIPRO MINI and NANOFLASH are the most popular units for this criteria, typically operating at 50-100Mbps in XDCam 4:2:2 or in ProRes 4:2:2 at 220Mbps. These units utilise the ubiquitous Compact Flash cards that are readily available in any retail outlet, which could of course be invaluable to some productions.

The two other factors in determining the correct device for your project are based on workflow and the physicality/functionality of the unit.

  The higher the recording spec, the greater the data rate and storage needs required both on set and in the post production environment, which will obviously have budget and time implications.

Also, it is the physical connection to the camera that has bearing on unit choice. The more recent machines such as CINEDECK and GEMINI also have built in monitoring and 1st AC visual aids and are designed to be camera mounted, although the GEMINI has a less superior picture then the CINEDECK, it weighs nearly 60% less and has a much smaller form factor. The NANO and KIPRO are a simple rear mount solution on the camera but offer no other functions other than the recording options.

As always when adopting new equipment or a new workflow scenario, VMI recommend a thorough test from acquisition through post in order to determine the suitability of a system for your project. Hopefully the above will begin to assist the decision making process and below we have a small summary of each unit’s specifications.

  1. Cinedeck:  A top of the range external recorder for high end Digital Cinema acquisition.

    Cinema-grade external portable HD recorder with 4:2:2, 4:4:4 and 3D capability with a built-in high quality 7" HD touch control daylight-viewable monitor.  It records to solid state drives (SSDs) for extreme reliability.  As well as uncompressed 4:2:2 or 4:4:4 (10 bit), this recorder is compatible with all of the major top-end Codecs (CINEFORM, PRORES, AVID DNxHD), as well as ARRIRAW (2012 release) and Sony S-Log.  The outstanding display makes this an obvious choice of recorder but the weight of the device (1.8kg) may not be best-suited for productions with lots of shoulder-mount shooting, unless the recorder is tethered by means of a cable to ‘video village’.

  2. Gemini:  The latest external recorder to be released which now also records ARRIRAW when using the ARRI Alexa.  Like the Cinedeck, it records to solid state drives (SSDs) in uncompressed 4:2:2 and 4:4:4 and shares all of the same Codecs and functionality as CINEDECK but the built-in 5” HD monitor is not as high-quality  but at 680g, it is a much lighter device making it more suitable for on-camera operation and capture. Gemini, can offer a parallel record ‘pseudo RAID’ setting, although with SSD drives being particularly robust, it remains to be seen whether this becomes a popular practice.

  3. NanoFlash has become the de-facto external recorder for non-broadcast HD camcorders, such as Sony EX-3 and PMW-F3, allowing them to instantly record in a broadcast-accepted 50Mb/second XDCAM HD 4:2:2 codec, enabling these cameras can shoot for all HD channels worldwide.  It is robust and lightweight at 1.2kg and records to 2 x fast Compact Flash cards of generally 32GB each, permitting 2 hours of HD capture.  Faster bit rates are permissible but these are generally not used, as they entail significant render time in post and most post systems do not allow easy ingest of the higher bit rate codecs compatible with NanoFlash.  The bit depth of 8 bit 4:2:2 can be limiting on  high-end productions. 

    Compatibility with the XDCAM HD and MFX Codecs mean that media can be easily ingested into popular post tools such as AVID and FCP without issue.  It is a solid and reliable tool with a relatively frustrating user interface.

  4. Ki Pro mini like the NanoFlash, records  to 2 x Compact Flash Cards in native ProRes 4:2:2 in either HQ or standard modes.  The 10 bit recording capability means that this is a higher quality capture than Nanoflash but has been seen to have some stability issues when hot-swapping cards, therefore VMI recommend a one card at a time procedure.  As it records native UDF format, it does not allow continuous record to span clips onto new cards when the existing card is full but on the plus side, it is small and compact and shoots on native ProRes , allowing ‘drag and drop’ to external hard drives to be immediately available to Apple FCP.

  5. PIX-240 Portable off-board HD recorder adds Quicktime recording using Apple ProRes or Avid DNxHD to any HDMI or HD-SDI equipped high-definition video camera. The portable PIX 240 records Quicktime files to CompactFlash cards or removable 2.5-inch solid-state hard drives.

Gerard's Verdict on the Gemini

This unit has been developed as a standalone lightweight external recorder without compressed codec integration but more in an uncompressed multiple still frame-by-frame recording device in the form of a DPX file format. The idea behind it is to capture the highest amount of data acquired by a camera and is more effective in conjunction with a logarithmic compression like the Sony S-log or the ARRI log-C capturing mode seeing both dpx and logarithmic capturing requires extensive post production work which could be done simultaneously. It is similar to the old film environment of telecine with regard to a scanned negative in DPX format, then graded and taken to the non linear editing environment. The result is to increase the latitude in post in common with film and reduce the reliance for on-set grading and transcoding, so now pictures are graded in a controlled environment with proper graders and editors.

The DPX file system is a still frame-by-frame environment and transcoding is almost flawless and clients from a film background or stills time-lapse experience would be comfortable with this workflow, as opposed to converting codecs which can be time consuming and adversely affect quality.  The unit will also soon support ARRIRAW for the Alexa camera soon for the ultimate in quality.  The unit is also capable of showing a client a look up table (LUT) output, to apply a graded look during monitoring as opposed to a very unflattering logarithmic look which has a much flatter look and is the way pictures are recorded to increase the latitude.

The unit is very light and supports dual HDSDI input for 444 full colour spectrum recording and takes 2 solid state drives, which have no moving pars and thus little room for error. The drives are also much larger (256GB) than conventional card formats.  The only downside to these drives is that it they are expensive – but think of this as an insurance policy!.

The post production process, whilst fairly straight forward, can be very tricky if you don’t understand the workflow.  High end producers from a film background would find this easy but someone from a a video background must familiarise themselves with the grading process before editing.

The DPX files open natively in Adobe Premier and the higher or later AVID systems but Metafuse may be needed for older avid systems.

Apple Final Cut Users can work in one of two ways.

Firstly, as per the Film World - Grade first, where the DPX files are natively supported in Final Cut’s Color which is free but clunky and difficult to use as it is more of a colourist tool.  Then import and transcode to Final Cut Studio.

The better way is to use Glue plug in tools, so that DPX files can be directly imported to work in Final Cut Studio or Compressor, however the downside is that this is rather expensive.

The Da Vinci Resolve Lite system which is free, also works very well with DPX files but like Colour is very complicated and more of a Colourist tool.

Adobe Premier works flawlessly and offers native support to DPX, allowing you to play back on the timeline with no rendering required.  DPX files are also native in the After Effects program.

The unit has touch-screen interface which is very easy to navigate and quite responsive.  It is a powerful tool and it would need a lot of storage but delivers high data rates capturing logarithmic compression flawlessly for superb latitude. The idea of doing a LUT and future ARRI RAW on such a small machine is clearly a big help on mobile handheld, steadicam and other form of production environments where large recording devices can hinder operation and creativity.  Gerard Botha

VMI Test on External Recorders

VMI In house test on external recorders, using a sony F3 camera with a single to dual stream and eventually the 3G HDSDI uncompressed signal onto various external recorders starting with the low internal recording settings for evaluation purposes.
Recorders used is the convergent design nanoflash, AJA Ki pro mini, cinedeck extreme and the new convergent design Gemini 444 recorder.

The whole sequence was edited on the new Adobe premiere 5.5 with no grading and no transcoding was needed whilst working on a 2k uncompressed 10 bit timeline.
The s-log clips was graded in After Effects.

None of camera settings was touched apart for the external recorders and the feed to them.

This Sequence was Compiled by:
Ian Jackson - Associate BSC, Feature and Drama contact liason
Gerard Botha - Head of cameras.

 

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