We
had been set to record HDCAM aerials over Italy using the
stabilised Cineflex HD camera and judging by previous
shoots results would be stunning. The
problem with HDCAM is that it isn't the ideal format in
the back of an aircraft if you want to record 24p or 25p
as one needs a heavy studio recorder that runs on
mains. So
when Getty Images expressed a preference for 4:2:2 and
the new SRW1 became available momma mia, a smaller
lighter less power hungry, higher quality alternative to
HDCAM‚ don't we love Moore's law! the production
company Skyworks jumped at the chance. The
HDCAM deck would remain a backup as ballast in the boot
of the production van rather than sacrificing its weight
for fuel in the helicopter. The
SR field recorder is comprised of two parts. The SRWI
recorder and the SPC processor The
combo is being called the SRW1 field recorder by
most. We
can assume that the SRW does most of the work; it
contains the tape drive and is considerably heavier and
more power hungry than the SPC processor. The
form factor is novel and bizarre, in looks at least. The
SRW clamps onto the top of the SPC.However despite
looking like a double storey ghetto blaster its
functionality reverts to the familiar Sony field
recorders of a top tape loading slot with inputs and
outputs down one side and a big handle across the
top. However
there is one difference in previous field recorders which
is the lack of inbuilt controls, other than eject, on the
unit. A cool looking remote control is provided which can
be extended from the recorder by cable. It displays
timecode, audio levels for 12 channels, warnings, channel
condition time frame rate, conventional vtr buttons a
mini jog push button and curious large wheel which didn't
seem to do much on the preproduction model we were
using. The
remote can be secured to the top of the srw one with a
hot shoe. I'd prefer a set of emergency use buttons
somewhere as the remote control or its cable could be
damaged in the field. Without the remote it's the end of
the shoot! If
the first impression is bizarre looks the second
impression is its sound. The cooling fans were on
continuously and made considerable noise. Interior sound
recording within a distance of 6 feet of the unit would
be troublesome. For dramas I imagine well ventilated
soundproof box may be needed or a longer extension cable
for the remote so the unit can be operated off set but
monitored on the remote on set. However
as the unit itself did not get too warm there may be room
for reducing the airflow and the power management is
often handled in software so I would hope that the fans
would become a little quieter in production models. Part
of the reason for the noise is that the combined power
drain is 95watts so there is a lot of heat to dissipate
by fans, The SRW1 draws 60 watts and the processor 35
watts Careful
attention must be made that the power supply and cable is
capable of providing at least 8 amps.The most recently
built field equipment is designed for 50 to 70 watt
maximum and so will be struggling with 95 watts. A trusty
old AC500 can cope with 120 watts as can some selected
new power supplies. I also enlisted the help of the Black
Box Video battery box, ‚ "The Big One" capable of
running the recorder for almost two hours if we blew a
fuse in the aircraft and useful for checking back
recordings on the ground without derigging the
aircraft. About
the only trap I found and was warned about in advance,
occurs when changing frame rates, as one must adopt the
f500 routine of ejecting the tape and rebooting. In fact
the tape must be ejected before the new frame rate is
selected in the menu otherwise, even if you reboot the
frame rate will not change. 12
channels of audio are available in the SR format, however
the SRW has only 4 canon 3 pin inputs. There is ASEBU
digital input and output to access the other
channels.Video inputs are split into A and B channels.
When recording 4:4:4 two channels of video are required
from the camera (dual stream). When recording 4:2:2 the A
channel is the default input. Monitoring
outputs are clean HDSDI for A and B channels and a second
monitoring HDSDI output with switchable character
generator overlay. When inputting 4:4:4 the HDSDI output
provides a useful means of monitoring as the processor
converts RGB to Y PB PR. A
SDI output, is available and can be configured for
squeeze, crop or letterbox. The SDI output cannot be
switched to composite. It creates 2:3 pull down when
shooting at 23.98p Timecode
in and out are positioned on the SRW1. HD reference is on
the SPC. There
is one power switch for each unit, with the SPC having
the master power switch. The
new menu isn't too bad, but allow 30 minutes for
familiarisation to reduce the likely hood of panic
attacks. Selecting format and frame rates is
straightforward and both options are on the same page in
the menu. There is a line of buttons on the remote that
jump the menu to Time code, video, audio, system and
home. This is very helpful but time code is adjusted by
jog wheel and is some what buried in the menu and with
Italian flight time costing 26 Euros a minute the wasted
seconds add up. Recording
is within 1/2 second from pause mode. Colour bars and
black can be generated, a very useful feature, a wider
choice of colour bars would be welcome. The machine
accepts small cassettes only. A 40 minute will run 48
minutes at 25p 50 minutes at 24p when recording 4:2:2.
When recording 4:4:4 or stereo recording times are
reduced. Sony
say that they have improved tape technology this is born
out by the tape length being longer, however as the tape
travels faster there is no significant change in running
time over HDCAM tapes. The cassette shell is a beige
white reminiscent of the colour of the first floppy disks
and has improved finger grips to help open the
case. A
modified SRW sits atop the Genesis camera. The question
is whether the Genesis has an internal MPEG processor or
if all the signal processing is housed in the SRW. The
likely hood is that most of the processing takes place in
the SRW1. You may question then the size of the SPC.
There is a future upgrade that will install a fibre optic
connector on the unit so the form factor is about right
for remote recording of a location drama and any studio
programmes. A camera remote control can be connected to
the unit and presumably this signal will be carried over
the optical fibre interface to the camera, turning the
SRW into a HD hub. The
temptation to mount the SRW1 on a Viper will continue,
but a combination of power drain, weight and noise of the
SRW1 makes it a questionable combination in the
foreseeable future. We
paid particular attention to EMI radiation. Computers
control many modern helicopters. A couple of mysterious
engine shutdowns have been blamed on high tech, "carry
on" equipment so it is prudent to check all aircraft
systems with a new recorder. We didn't expect any
problems and there were none. The
other issue is susceptibility of the recorder itself to
RF radiation from aircraft systems. Flying fashionably
low near transmitter masts we had a twenty second RF hit
on tape. This kind of RF interference close to powerful
sources is not unusual. The effect was quite obvious on
the monitor and on replay the interference on tape
occurred at the same time and for the same duration as it
presented itself on the monitor at the time. This
experience suggests that the recorder itself is well
shielded and the rf was being picked up from the camera
head or the two lengths of 6 foot cable between gimbal
and recorder. What
one fears most with a new recorder is exterior RF
interference that goes to tape that is not evident whilst
shooting on a monitor. The
unit can also record two separate HDSDI 4:2:2 streams
from two sources. Rumoured to be prompted by a request by
James Cameron who wants to shoot more 3D using HD, this
feature will be available to all. So
a two camera drama couldn't be be easier to synch up.
However the SRW must be used to digitise the rushes as
the SR5000 studio deck does not support the dual picture
mode. The
most versatile feature of the SRW1 is its ability to
switch compression ratios. In
4:2:2 mode it compresses 2.7/1 for a data rate of
440mbs In
4:4:4 SQ mode it compresses 4.2/1 for a data rate of
440mbs In
4:4:4 HQ mode it compresses 2/1 for a data rate of
880mbs In
stereo 4:2:2 mode two separate 4:2:2 pictures are
recorded at a rate of 880mbs It
achieves the 880mbs rate by running the tape at double
speed, thus halving the maximum recording time to
25minutes. A future upgrade will also enable the SRW to
record 720 60p. Not
only does it switch tape speed it also switches
compression schemes. The SR format uses intra-frame
compression for progressive and intra-field compression
for interlace recording. As
usual with new HD kit there is a need to create your own
terminology, we need a description of stereo recording in
compressed 4:2:2 that is not confused with dual stream
4:4:4. How about stereo 4:2:2? It
may be that 4:2:2 recording will be superior for some
projects due to the higher compression in 4:4:4. The
double speed 4:4:4 recording will be the choice for
bluescreen, normal speed 4:4:4 with 4.2/1 compression
will need to prove itself. It
is useful to have a choice! Up
to three SRW1s can be daisy chained together so duplicate
recording or continuous recording without stopping is
possible from the one SPC. We
chose 4:2:2 due to the increased recording time in
comparison to HQ 4:4:4, this meant less tape changes in
flight, lower dubbing charges and lower stock costs.
Since most aerial footage is not heavily graded it may
well be that 4:2:2 will be a sensible choice for long
form aerial projects. Also TV oriented 4:4:4 post houses
are thin on the ground at the moment. Instead
of 1440x1080 pixels recorded at 8bit as with HDCAM, the
SR records 1920x1080 pixels at 10 bit. Colour sampling in
4:2:2 is 960x1080 pixels rather than 480x1080 pixels of
HDCAM. Although
you would be hard pressed to tell the difference on
standard def TV on a large screen the extra detail of
4:2:2 makes the incredible detail in an aerial shot
really shine. 10 bit rather than 8 bit will ensure
minimal degradation in post. We
flew for 18 hours over 5 days pretty much rolling on take
off and not shutting down until we landed. The shipping
weight of 18 tapes and the SRW1 was less than a typical
hard disk recorder with just 50 minutes of 4:2:2
recording. The trade off is that the SR is more expensive
to dub or digitise. A hard disk simply plugs into the
edit, but taking enough drives abroad for 18 hours of
4:2:2 is still a daunting proposition. In
the past Sony have rolled out low cost players for new
tape formats at their discretion, however now that hard
drives are a viable working alternative to tape there
will be some instances where the cost of digitising will
swing productions away from tape so the SR format may
need a low cost player to be introduced more quickly than
previous formats. Our
solution to the relatively high cost of dubbing any HD
format was to simultaneously record on a DS70AP DV
recorder. This is the only Sony 12volt powered DV deck
with SDI and timecode input. However
if there was a 12volt XDCAM it would also be suitable, as
would a DV drive, but the production company had a DV
capability in their own edit suite so we decided on DV.
This was fed from the SDI output and timecode fed by
cable. Promise
of 1920 x1080 60p recording for slo mo will make this a
versatile machine and possibly the last in a long line of
Sony field portable tape machines? Current
price of the unit is somewhere between 75000 and
¨85000 euroes.Tape stock is currently 75 euros for
40 minutes. Judging from past experience with HDCAM if SR
becomes more popular the price will fall
further. So
George Lucas ‚gave us Progressive scan f900 and
James Cameron a two for-the-price-of-one stereo HD field
recorder. Now
if only Spielberg was as big a fan of HD! Interested
in more
aerial information? This
artical appeared in November 2004 edition of High
Definition Magazine
www.definitionmagazine.com