First Aerial Shoot (aka I'm freakin' out)

James Leonzio · July 16, 2012

So I've been contracted to do a few basic aerial shots of skylines and a few approaches of a particular skyscraper in the downtown Houston area. We'll be keeping it really simple camera-wise, just a 5D mkiii with a zoom and zoom control.

After all the horror stories of Helicopter shoots gone wrong, I'm trying to reach out to as many sources as I can, before I get up in the air. I am currently working with the following company, trying to work out all the details of the particular mount we would be using (a custom gyro stabilized mount they designed)

http://www.paradigmhelicopters.com/aerial-photography.php

If anyone has any insight on who to talk to, and what questions to ask when it comes to aerial work, I would really appreciate it. Safety is my number one concern here, so please, whatever help you can offer...

Nicolas Gomez · September 19, 2012

We´ve seen a lot of tragedy going on with those rigs... We rather use a standar RC helicpter with a nice Gopro for budget production, if anything goes wrong a Gopro will survive! If you need it on 35 then best of luck with the adventure!

http://www.elsotano.com.co/videos.php

Tom Jensen · September 19, 2012

Stay wide to lessen the shaking. keep it level

Brian Drysdale · September 19, 2012

A lot of the helicopter incidents happen with low level shots, if you're doing skylines with pretty standard manoeuvres you'll be safe enough. You'll probably be best doing this early in the day, the light is more interesting plus you'll have less turbulence from the heat.

Tom Jensen · September 19, 2012

Morning light is beautiful but sunsets last a lot longer.

Edited September 19, 2012 by Tom Jensen

Phil Rhodes · September 20, 2012

What I don't get is how you can afford a helicopter, but you can't afford a better camera than a DSLR!

Mathew Rudenberg · September 21, 2012

What I don't get is how you can afford a helicopter, but you can't afford a better camera than a DSLR!

Seriously, DSLRs are reasonably good when you're on a longer lens and throwing the background out of focus but they are notorious for having a fairly low measured resolution (just under 720p), which means on wide angle shots where everything is in focus it frequently looks like nothing is.

Also you're going to get a lot of repetitive details (like windows on a skyscraper) that are prone to causing moire.

Finally, if there is vibration the image will wobble due to the rolling shutter and you won't be able to stabilize it.

Wouldn't you be better off putting a couple of extra bucks in for an F3 or a C300, or failing that even an EX3?

Chris Millar · September 21, 2012

which means on wide angle shots where everything is in focus it frequently looks like nothing is.

True ;)

Different but same same ... reminds me of old (old) trick of Dallmeyer Petzval type lenses - they purposefully reduced the sharpness of the image on the focal plane, and by doing so creating a larger band that was equivalently in (or out of) focus - i.e. a 'larger' DOF

Phil Rhodes · September 21, 2012

F3 and C300 are both rolling shutter as well. Almost all modern cinema cameras are, right up to Alexa, although the effect is microscopically subtle in that case.

Stuart Brereton · September 21, 2012

F3 and C300 are both rolling shutter as well. Almost all modern cinema cameras are, right up to Alexa, although the effect is microscopically subtle in that case.

The rig appears to be gyro stabilized, so rolling shutter artifacts from engine vibration shouldn't be an issue.

As far as operating goes, remember that the pilot does 80% of the camera work for you. it's all about communicating properly to him how you want to be positioned in relation to the subject. If he's experienced enough, he probably won't even need to be told.

Richard Brooks · September 26, 2012

Hi,

I've been doing some research into this as well for the project we are running here.

You'll get the jello effect from a CMOS camera due to the rolling shutter. Better to get a CCD cam like a Z1 and use that.

Richard

Stuart Brereton · September 26, 2012

You'll get the jello effect from a CMOS camera due to the rolling shutter.

Not if the rig is properly gyro stabilized.

Jaron Berman · September 30, 2012

The rig appears to be gyro stabilized, so rolling shutter artifacts from engine vibration shouldn't be an issue.

As far as operating goes, remember that the pilot does 80% of the camera work for you. it's all about communicating properly to him how you want to be positioned in relation to the subject. If he's experienced enough, he probably won't even need to be told.

From the picture, it looks like an aerial exposures mount - not custom at all. Although perhaps they swapped out bungees or something and slapped their stickers on it? The performance of an AE mount is very dependent on the weight of the camera payload and also how balanced you can make it.

Gyros work using "brute force" inertial stabilization. Inertial stabilization also encompasses things like dolly, steadicam, any smooth movement that's not "actively" stabilized. P=MV . Inertia = Mass * Velocity. The more inertia you have, the more stable the shot will be. So to make more inertia you can increase mass (dolly) or velocity (gyro) or both (really fast moving dolly). A gyro as found on the AE mount is made by Kenyon Labs, and they have a lot of different models that can stabilize different payloads. Gyros themselves (kenyon) are very precisely machined and balanced tungsten wheels that spin inside a helium filled envelope. They spin about 14,000rpm if i recall, maybe more - so they whine and also take 20 minutes to get up to speed. Also, they're very sensitive to "caging" - if you're able to forcefully overcome the gyro's desire to stay in one direction, it's not very good for the bearings and shortens the life/kills the gyro. How easy it is to cage the gyro depends on how appropriately you've selected the gyro to the payload, BUT you need to feel-out the maximum speed you can turn a gyro because by design, it wants to fight you from moving it at all. It's a bizarre feeling if you've never held one, but it's a little 5-9lb egg that resists angular motion. So panning, tilting, etc - all must be done slowly and smoothly to prevent caging.

Why all the tech background? Because of exactly what Stuart said - with these mounts, the pilot shoots the shot as much as you do. It's all about inertia of the camera. Inertia - the tendency of an object in motion to stay in motion - is what you're looking to maximize. The other way to make a smooth shot is to minimize other forces - you controls, abrupt helicopter movement, etc. You're basically just gently supporting the camera in an AE mount, not really "pointing" it so much as correcting the direction it wants to point. The helicopter is your most effective pan control. Good communication with the pilot is absolutely critical, because like many specialty types of piloting, he's flying the payload not the aircraft - i.e. the type of maneuvers he performs all relate directly to the task at hand, always flying the shot unless it's unsafe to do so. Helicopters can fly in any direction up to a certain speed, though you'll find that some directions are more comfortable and shielded from wind (another external force acting on the camera mount). You'll be shooting out the side so your speeds "forward" (at the lens) are limited.

And yes - wide angles are easiest to hide vibration. The reason the cineflex costs what it does is because it can effectively stabilize a VERY long lens, longer than any other commercial system I'm aware of. The gyro mount you're going to work with is nowhere near as complex, though it's similar in performance to some of the older Tyler mounts that the vast majority of aerial footage was shot on for cinematic release (if not handheld).

Your best approach is to look at maps, weather, sun charts with your pilot - chances are that company has done this before. And also listen to the pilot about his/her experiences doing exactly this. Plan out the shots you "must get" and the be open to the bonuses or suggestions that he/she may have for additional. Low and slow are dangerous, but otherwise - if it's a reputable company and you're not overflying the aircraft, it'll be fun and safe. Just make sure that with doors off, anything you want to keep (including yourself) is properly secured/strapped in.

Gregg MacPherson · September 30, 2012

..... Inertial stabilization also encompasses things like dolly, steadicam, any smooth movement that's not "actively" stabilized. P=MV . Inertia = Mass * Velocity. The more inertia you have, the more stable the shot will be. So to make more inertia you can increase mass (dolly) or velocity (gyro) or both (really fast moving dolly)..........

Some thoughts on the physics (without the gyros for now).

Mass * Velocity = Momentum. In straight line motion an inertial force F is felt when velocity changes.

F=m*a with "a" being the acceleration. But it normally looks to me that stabilisation rigs like steadicams and the lightweight variants are designed to smooth out the angular rather than linear movement of the camera. The distribution of masses in the rigs look designed to give rotational rather than linear inertial reactions.

Torque = moment of inertia * angular acceleration.

Moment of inertia = Sum of (m * r^2) .... meaning that you take each mass and multiply it by the square of the projected distance to the rotational axis.

It looks like a common feature of steadicams and the lightweight rigs that masses are spread to increase distance r from the rotational axes. The torque required to disturb the camera increases with r^2. And the angular acceleration term. The torque (inertial reaction) being proptional to that means that the more sudden the disturbance the higher the inertial reaction that resist it will be.

Cheers,

Gregg

Edited September 30, 2012 by Gregg MacPherson

Brett Graybill · October 7, 2012

I recently had a similar issue facing aerials. How do I shoot within budget and maintain a stable image? I was freaking out, then a DP told me he knew two DP's who went down in aerial shoots! In my paranoia I found someone with a paraplane and went up for a test. The results were pretty decent on a DSLR and a heavy shoulder rig. If you need long takes or fast traveling shots then I wouldn't recommend it, but it can fly as low as 10ft and high as 15,000+ (on the cheap).