Wednesday, April 28, 2010

Bizarre video artifact...

Robb's post here led me to this wild video of a turboprop in action. The spinning prop and the iPhone's video recording properties create something that hasn't been seen in the air since Timothy Leary last looked out the window of a puddlejumper. I can see the music!

22 comments:

Alan said...

Trippy

Ted said...

Looked like the prop was feathered. That might be an artifact of the recording because it also looked like it was rotating backwards.

Ted

Tam said...

It may just be the 'shrooms.

Keads said...

And here I am trying to put trippy stuff up too! I guess it's a overload of trip!

Cool video though! There used to be a time where techs used strobes and stuff to balance wheels on cars while they were attached to the car.

Shutter speed and all of that comes into play.

Days long gone!

USCitizen said...

Way cool.

Anonymous said...

You people waste entirely too much time on weird "trips" on the 'toobs!

(watched it three times; better special effects that anything Cameron has done)

AT

Fred said...

I saw that one too... I couldn't watch the whole thing. Way too sober.

Anonymous said...

That seems like it could used as a neat, on-the-cheap special effect in a sci-fi film. Looked very cool.

Kristopher said...

Video cameras with anti blur software also do similar things ... like video tape of Helicopters floating in mid air with apparently non-rotating main rotors.

Accidental stoboscopy caused by the CCD frame capture rate.

Robb Allen said...

Bah, you people and your technical explanations to what is clearly black magic.

reflectoscope said...

Such propellors are a tangible hazard on the ground during startup, because they cause a strong urge to walk toward them.

Jim

Ted said...

:::::Quote
Such propellors are a tangible hazard on the ground during startup, because they cause a strong urge to walk toward them.

Jim
::::::::End Quote

I don't know about that. It is my belief that on loud/busy airport ramps some peoples minds just turn off. I watched a ramper tackle a passenger once who was yelling "that's my plane" while running straight at a 10' dia 1800hp Cuisinart.

Ted

Ed Foster said...

Hamilton-Sunstrand 14RF prop in front of a GE CT-7 turboprop. Looks like the old Fairchild housing or something similar. Maybe a SAAB 340 or a Sukhoi-80.

36 years in yankee job shops, making either guns or airplane parts, and I was a contract engineer at Hamilton for quite a while (it's just over the hill from the house).

I still hit the bar at the Skyline Steakhouse up on Rt. 72 every now and then for afternoon B.S. sessions with the techies.

There is an engineering term called elegance, meaning the simplest answer to a complicated proble. It's usually a trademark of American engineering, although the Frogs are quite good at it too, and the Japanese most often run a good third.

The 14RF dash 19's and 21's did away with all the hydralics and counter weights, and used the airpressure on the hub to balance the blades during pitch change. So simple, so sweet to watch, and only a 10db noise load in the cabin.

Hamilton was fun. They friction weld the big C-130 hubs to their drive (top) shafts. The front of the shaft is cut in a cone, and the rear of the shaft has a matching recess. They would spin the bugger up to 35,000 rpm and mash them together.

Even with all the soundproofing in the world, the vibration passed all through the fabric of the building, and everyone would stop for a moment and grin. We made the best in the world, and each time it happened was like a baby being born.

And Jim@reflectoscope, I don't walk toward them, but there have been moments I stood there stupidly, longer than I should have, as one of them came toward me.

My old man talked about that more than once, whenever somebody walked into a prop out on the flight line at Pensacola or Jax.

Stretch said...

So that's what William Shatner saw.

Anonymous said...

they've got a name for that:

http://en.wikipedia.org/wiki/Rolling_shutter

Kristopher said...

Here is the example ... failblog was kind enough to rerun it today:

http://www.urlesque.com/2010/04/28/magic-helicopter-flies-without-blades/?feedItemId=5939&siteId=73

reflectoscope said...

Ted: There are definitely people who step out of the terminal and go... terminal I guess, but this is as far as I can tell an involuntary thing. I saw it live and up close standing about 10 feet from a King Air B90 that cranked an engine, and I was expecting the start-up, too.

Jim

loren said...

so, how did you get past the commercial for 8 year old girls?

dave@pervasivelight.com said...

It's one of two things;

1. Rolling shutter artifacts

2. Black magic

My money is on option 2.

reflectoscope said...

Loren - Firefox + Adblock Plus + No-Script + Flashblock. I'm not sure exactly which element on that list gave that ad the boot, but I didn't see any ads when I watched it.

Jim

jeff said...

Way too cool.

Geodkyt said...

Rotors can be hypnotic.

I watched a kid walk into the tail rotor of a Huey once. A noise I can't even begin to describe (followed by an even weirder and scarier noise before the pilot go her shut down), a round object flying past the corner of my eye into the woods, and a pair of boots on the ground outstretched on the ground, visible past the body of the aircraft.

Luck SOB had a concussion and a pressure cut across the forehead. His antique, nasty, sweat grimed, half-rotted chinstrap parted and it was his steel pot we saw flaying away.

No one would loan him money after that. . .