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Orion HD Camera Rig

orion_front_mattebox_side_battery_small.jpg

The development and evolution of high-quality CMOS camera chips enabled everyone to take pictures digitally (without more operating costs for film & exposure to paper). Today, people show and share millions of images online and a picture can often say more than thousands of words.

As soon as DSLRs started to offer serious 1080p video capabilities (beginning with the Canon 5D), a whole new world opened up, giving independent film producers a relatively “cheap” tool to create high-quality film material. Moviehackers started to embrace the technology and are using Canon 5D/7D and Lumix GH2 in many projects to create free movies out of passion, not for money but for people.

If a single image can say more than thousands of words, how many words can a movie transfer? Videos are probably the most efficient way to transfer knowledge, practical HOWTOs, motivation and of course entertainment to someone else.

Now we have the equipment to capture (create), free open-source software like cinelerra, blender, ffmpeg and gstreamer (edit/process), the internet as a free broadcast channel (distribution) and decentralized/interconnected media delivery systems like MediaGoblin.

Commercially available and production grade cams are very expensive and thereby totally out of the scope of our budget. Luckily, the Panasonic Lumix GH2 and the open and hackable firmware for that cam, made it an ideal alternative. To make the cam a bit more production friendly a modular rig was built to increase the comfort and efficiency of the production process on DSLR/system cams.

Although the Orion HD Camera-Rig was initially built to support the GH2, the rig can also be used to host all kinds of cams, like the Canon 5D or 7D.

Orion, deprived of his sense of vision and cast out onto the dark sea, proceeded east to meet the sun-god, who restored his sight with a beam of light.

Base Rig

orion_side_ff_disp_body_cntr_small.jpg

  • 4 carbon fibre base rods
  • TrusMT Cheeseplate + Quickmount
  • 2 aluminum cage holders + grip
  • Custom built battery holder

Camera Body

orion_side_ff_disp_body_cntr_closeup_small.jpg

  • Panasonic Lumix GH2
  • Hacked firmware: 46 MBit/s AVCHD codec bitrate (1080p@23.978fps cinema mode)

Mattebox & Lenses

orion_front_lens_mattebox_ff_full_small.jpg

TrusMT Mattebox

  • Frenchflags
  • 2 separate, rotatable 4×4 filter frames
  • height-adjustable
  • 4 different donuts

Production

  • Panasonic Kit Lens (MFT)
  • Canon EF 16-35mm L (EF→MFT Adapter)
  • Canon EF 70-200mm L (EF→MFT Adapter)

Effects

  • Schneider & Kreuznach 100mm (CS→MFT Adapter)
  • Lens Baby (EF→MFT Adapter)

Follow-Focus

orion_front_lens_mattebox_ff_small.jpg

  • TrusMT Micro Follow-Focus FF-NF4
  • Hard A/B Stops
  • Versatile mounting options
  • Possibility to add a stepper motor for remote controlled focus

Power Supply

orion_back_battery_ctrl_mattebox_small.jpg

Once the camera was in the rig, changing the original Li-Ion battery became a real challenge. Panasonic's product designer probably never intended it to be more than a consumer device, so the battery can only be accessed from the bottom. Although the cheeseplate comes with a quickmount plate, that makes it easy to remove the camera from the rig, one still has to unscrew the quickmount plate to get to the battery and afterwards realign the quickmount plate and the camera with the rig. Changing the battery took about 15 minutes which was unacceptable, considering the battery had to be changed every 45-60 minutes.

A completely new system had to be created, using cheap & off-the-shelf RC-LiPo battery packs, a very efficient switch-mode power converter, designed for the particular use case, a stable battery mount on the rig and an industrial grade IP67 power/control/charge quick-plug system. In this configuration, the battery needs to be changed only every 5 hours of recording time or 2 hours, if using and powering an external field-monitor as well.

Battery Adapter

Power Supply Unit

Orion's PSU is a state-of-the-art switch mode power supply, designed specifically for the GH2, to always operate above 95% efficiency (standby, idle and recording with higher codec rates than 22MBit/s). This increases battery lifetime and offers stable power output for the camera - to avoid interrupted takes due to power fluctuations.

Specs

Input Voltage 10V - 14.4V DC
Output Voltage 8.45V
Output Current 2A (max continuous)
Output Ripple 10mV P-P
TPD 0.4W
Efficiency 95-96% in typical operating condition

[Power Supply Unit Results]

The GH2 checks the power input and determines if it's a battery or a power supply. If the supply voltage is not coming from a battery and is lower than 8.4V the GH2 will refuse to boot.

Schematic

[Schematic of PSU]

BOM

Part Number Vendor Component Names # Price Cost
08055C393KAT2AAVXCss1$0.11$0.11
B230A-13-FDiodes Inc.D11$0.58$0.58
C0805C103K5RACTUKemetCbst1$0.07$0.07
C2012Y5V1E105Z/0.85TDKCinx1$0.22$0.22
C3216X5R1C106MTDKCout3$0.42$1.26
C3225X7R1E106MTDKCin2$0.83$1.66
CRCW0805158KFKEAVishay-DaleRt1$0.09$0.09
CRCW08051K00FKEAVishay-DaleRfb11$0.09$0.09
CRCW08055K62FKEAVishay-DaleRfb21$0.09$0.09
LM22680MR-ADJNational SemiconductorU11$5.10$5.10
SRR1280-270MBournsL11$1.01$1.01

Kits

When enough people, who also have a GH2 and want to use cheap external LiPo-Packs, we can create a cost-effective kit. Buying parts in large quantities will lower the price an individual can achieve.

LiPo Battery packs

orion_battery_controller.jpg

The battery-packs are based on a 3S (11.1V) / 5000mAh (Flightmax Zippy 5000 15C was the cheapest at the time) LiPo battery for power storage, enclosed in an IP67 protected alu casing with a heavy-duty quickconnect system. This system makes it possible for other rigs, for example the steady rig (yet to come), to use the weight of the battery-pack as counter-balance weight at the bottom, thereby greatly reducing the overall weight of the rig.

Controller

Basic Control

[Panasonic Lumix GH2 Remote-Control jack schematic]

Reaching the shutter (record start/stop) button inside the rig is not very convenient. In order to make it more reachable, a cheap ($5) shutter remote-control extension was reverse engineered to find out how it's actually implemented. Once the camera is in movie mode, the shutter button (and the remote control) acts as start/stop button and the focus button is a nice addition to leave the manual focus-assist zoom.

Advanced Controller

Workflows & Software

Convert GH2 mts to AVID dnxhd

for i in `ls *.MTS`; \
do ffmpeg -threads 6 -i $i -vcodec dnxhd -b 185M -acodec pcm_s16be $i.mov;\ done

Cinelerra Settings

  • Create cinelerra project with yuv422p
  • Render quicktime (yuv2) - audio 2nd order

Compress & resize for web

The following script makes the task of converting and reordering the headers to allow http pseudostreaming pretty simple:

#!/bin/sh

QUALITY=24
THREADS=6

case $3 in

1080)
  res="1920:1080"
  ;;
720)
  res="1280:720"
  ;;
*)
  echo "ERROR: No output resolution specified"
  exit 1
  ;;

esac

f_date=$(stat --format=%y "$1" | sed "s/ .\+$//")
f_year=$(echo $f_date | sed "s/-.\+$//")

### convert & compress ############################# 

ffmpeg -i $1 -y \
-threads ${THREADS} -loglevel quiet \
-metadata year="${f_year}" \
-metadata date="${f_date}" \
-metadata license="CC-BY-NC-SA-3.0" \
-vf crop=1920:1080:0:0,scale=$res \
-pix_fmt yuv420p -f mp4 -vcodec libx264 -crf ${QUALITY} \
-flags +loop -cmp +chroma \
-deblockalpha -1 -deblockbeta -1 -refs 3 -bf 3 -coder 1 \
-me_method hex -me_range 18 -subq 7 \
-partitions +parti4x4+parti8x8+partp8x8+partb8x8 \
-g 320 -keyint_min 25 -level 41 \
-qmin 10 -qmax 51 -qcomp 0.7 -trellis 1 -sc_threshold 40 \
-i_qfactor 0.71 -flags2 +mixed_refs+dct8x8+wpred+bpyramid \
-acodec libfaac -ab 192000 -ar 48000 -ac 2 $2.tmp 2>/dev/null

### reorder MP4 header for HTTP pseudostreaming ###

# this needs qt-faststart (qt=quicktime) which is part
# of ffmpgeg but some distros don't package it, be advised.

if [ $? == 0 ];
then
   qt-faststart $2.tmp $2
fi

if [ $? == 0 ];
then
    rm $2.tmp 
fi

Usage:

x264_webconvert.sh infile.mov outfile.mp4 720

For Screencast recordings:

RAW: ffmpeg -f x11grab -r 30 -s 1600x1200 -i :0.0 -vcodec rawvideo -pix_fmt uyvy422 -vtag 2vuy -threads 2 output.mov

Future Enhancements & Challenges

  • uC based camera controller (easy)
  • LiPo-Saver (easy)
  • RF-Remote Record/Stop (Advanced)
  • RF-Remote Follow Focus (Advanced)
  • Hack GH2 Firmware to support 1080p24(25) instead of 1080i50 on HDMI (Very Advanced)