HDSLR Custom Gamma Curve
The Canon EOS software package includes a utility called Picture File Editor that allows fine manipulation of the 5D/7D/… color and gamma curves, way beyond what’s available in-camera. Two screenshots below show my specific changes in order to add a distinct look and correct for some of my own pet peeves about the camera’s color and contrast out of the box. This curve is obviously intended for low-contrast scenes.
- crush blacks just a hair to give perception of graded contrast
- raise highs and mids to compensate for a consistent half stop of underexposure, which I do for maintaining highlights
- remove some of the ‘reddish orange’ in skin tones
- shift a little bit of green to blue, to correct for my specific non-Canon lenses
Review: Top Gear America, Episode 1
Good traction out of the gate, but several misfires suggest a slow first lap.
I was invited to attend the taping of the first episode today and here is my honest review. Sorry in advance if any feathers get ruffled.
When the cast list was first announced, I was convinced the program would be a dreadful exercise in self-deprecating agony. Turns out I was mostly wrong. Adam Ferrara’s standup comedy is not my cup of tea, but he is a charming cohost, bringing a lively jubilance to contrast the zombie state that embodies Tanner Foust. The third musketeer, Rutledge, of whom I hadn’t heard, is my favorite despite his constant grin of stupidity. The trick is when you put them all together, the individual weaknesses fade and the group forms into a rather pleasant, fun dynamic. Except for Tanner. He is an amazing driver and a solid race commentator, but simply dull as a talking head.
The whole Top Gear America experience is rough around the edges, resembling a poorly cast intake manifold that can only holds its pressure with double beads of sealant. It flows though, there is a pulse. The producers definitely know what they are doing, but my biggest fear is an expiring supply of material. They probably won’t talk much about car modding, since that’s out of style. They probably won’t talk much about car racing circuits, since nobody cares about those. Thus the remaining raisons d’etre are car reviews and comparisons, both already an oversaturated market of brand bias. Even stylistic vignettes and manufactured challenges may not be enough to hold the audience’s attention in this country. To keep me watching, the crew will need to go out, find some stories, and then tell them.
The segments are neat, but somewhat inconsistent in quality. Lots of influence from the BBC version with occasional low-budget camerawork; some of the stuff you can find on youtube is just as good, if not better. However, the personalities, especially Rutledge, humanize the challenges and make them fun to watch and experience, even when the pace slows.
Perhaps my words have been harsh so I must reiterate that there is a lot of potential here. This country needs more light-hearted family-friendly programming and Top Gear America shows that there is a glimmer of hope for the variety format, especially when it incorporates our favorite pastime: cars. Let’s keep the motor running on this one.
And here’s a review from my friends over at The Smoking Tire: http://www.thesmokingtire.com/2010/review-top-gear-usa-live-studio-taping/#more-4634
Homemade Gyro Power Supply
Bought a Kenyon KS-4 gyro stabilizer in good condition but missing the power supply. Got a great, amazing, killer deal. Unfortunately, Kenyon wanted $350 for a power supply. Not wanting to lose the sweetness of my deal, I decided to investigate why this unit was so expensive.
On the gyro cylinder, the inscription commands 120VAC @400Hz. 400Hz is an odd cycle I thought, but turns out to be quite standard for avionics. Kenyon’s documentation alluded to that power being readily available in most helicopters. However, I intended to use it on the ground and ideally from standard 12-15V battery bricks. I didn’t want to have to carry a helicopter in my bag.
12VDC->120VAC is easy, I can use a cheap car power inverter. 60Hz->400Hz, not so sure. An hour of search engine brought up a decade old usenet posting about how to change frequency by adjusting resistance and possibly capacitance. This is probably common knowledge for an electrical engineer.
Took a trip to the local electronics store to buy a $15 power inverter for a car that was rated at 150W. Hopefully it can handle 30W in reality. The gyro is rated around 24W of startup, 8W continuous.
Inside the inverter’s case, three variable resistors were easy to find. After tracing the circuit, it became a little obvious that two were not relevant to my interests. They were for an LED driver or something separate from the rest of the circuit. That left a single pot to tweak.
I hooked up live power, plugged in the multimeter to measure AC on the output, and began twisting the resistor. 82Hz, 90Hz, 108Hz.. well that was easy enough. After measuring the resistor to see how much each change in ohms affected my final variable, the frequeny, I collected a couple data points and approximated an equation.
I ended up using another resistor in parallel, got to 401Hz, and packaged it all up with electrical tape. To make the compact rig even more versatile, I wired in both a little battery connector and a cigarette lighter plug to feed the power supply.
That’s how you build a gyro (or avionic) power supply in two hours with $15. Been working well for 3 years in smoke, rain, snow, on the water, in the air, and up to 200mph on the ground. Another battle tested, battle proven hack.
Wireless HDSLR Video Trigger Handle
There is presently a lack of remote triggering options for the Canon HDSLR platform. But I had a need for ergonomics’ sake, so I built a solution: a trigger button and signal emitter embedded into a comfortable grip, and wireless.
The handle attaches to a quick release plate to which we occasionally mount a gyro stabilizer. This solution works very well and no longer requires the operator to touch the camera to trigger video recording. Instead, just a small thumb press and the camera blinks to life.
This was built specifically for a Canon T2i, but would also work with a 7D and 5Dmk2. Total parts cost about $10.
T2i Integrated Video Transmitter
fabricating the battery
power requirements of transmitter
video receivers