thePhotographySite.org

I’ve spent more than a year trying to build a helicopter that can lift a small DLSR and give clean, crisp stills and vibration-free video. I’ve built a variety of aircraft: some single rotor (with collective pitch) and several multi-rotor helicopters. I’ve also experimented with different camera mounts, and different flight control computers.

This is part 1 of a series of posts describing what I’ve found that works best and how you can build your own aerial platform (or what to buy if you want someone else to build it). This information can save you a year of trial-and-error experiments. Better, you can go straight to a solution that will work for you without wasting a lot of time or money.

First, here’s a picture of 6 rotor helicopter, a hexacopter, with a Skyrover camera mount and camera. I finished this one recently and it gives the best results for stills and videos that I’ve been able to get so far. In future posts, I plan to take you through every step of the build process. I’ll explain my choices and the reasons for them.

Hexacopter with Skyrover camera mount, MK electronics and D90

Here’s a view from the top.

Hexacopter with Skyrover camera mount and D90, top view

I’ve found that multicopter configurations with 4, 6, 8 or more rotors (propellers) to be the smoothest, most stable and easiest to fly. On these multicopters the rotor has a fixed pitch. So the only way to cause the multicopter to roll, pitch or yaw is by changing the speed of the motors relative to each other. Translating the joystick movements on a remote control into speed variations of the motors is done by an on-board computer. How stable the multicopter is in flight (especially in the wind) is determined largely by the computer and the quality of its software.

I’ve found that the computers made by www.Mikrokopter.de (sold in the US by www.Mikrokopter.us and by www.quadrocopter.us) to be particularly good and probably among the best available. I’ll discuss the reasons why I think they are a good choice below.

Another contributing factor to stability and smoothness in flight seems to be the number of rotors. Having looked carefully at dozens of videos, I’ve noticed that even with the best multicopters, there’s a little bit of jerkiness, or low amplitude, short duration roll movements. I call these micro-rolls. Usually, they appear as tiny and brief (barely noticeable) jerks rolling to the right or left. These movements are most often caused by sudden stick movements by the pilot. They are also caused by wind. They are subtle and most viewers don’t notice them. But professional videographers notice them. So if you have discriminating clients, you’ll want the smoothest copter you can get.

When comparing videos, my subjective judgement is that octocopters (8 rotors) show the least of these micro-rolls. If carefully flown, you can get very smooth movement with an octocopter sometimes with no visible micro-rolls in the video. It looks like the octocopter is on a pole, not flying through the air. Hexacopters can be reasonably clean too, but they seem to be a bit jerkier. Quadcopters are usually a bit worse. The reason octocopters are immune to these movements is that there is more mass at the ends of the arms. And the arms on octocopters tend to be longer to make room for the propellers. So it takes a lot more energy to roll or pitch an octocopter.

You might think that a properly stabilized camera mount would absorb micro-rolls. I haven’t seen one yet that removes them completely. Please let me know if you find one. The camera mounts tend to be better at removing slow, large amplitude movements. So, my recommendation is that if you’re building a multicopter for aerial photography, go with a 6 or preferably an 8 rotor design.

An actively stabilized camera mount can keep your camera pointed where you want it, even when the multicopter is pitching and rolling in the wind. The camera mount should also absorb vibrations caused by the motors and rotors. The Skyrover camera mount (available at MikroKopter.us) is an inexpensive mount with active stabilization for pitch and roll. It is designed to work with the Mikrokopter computer and software.

The Skyrover doesn’t have gyros or accelerometers itself for stabilization. It comes only with servos. It relies on the Mikrokopter computer (or similar) to provide the right signals to the servos. While this is a good arrangement and works reasonably well, it is possible to improve it. The main reason it’s not perfect is that the gyros, which sense motion, are on the Mikrokopter computer board. So they’re not actually sensing the camera’s motion directly. The camera is not rigidly attached to the multicopter’s frame. There are soft rubber shock absorbers connecting the camera mount to the copter. So a better arrangement would be to have the gyros mounted on the camera mount, so they are sensing the camera’s movement directly. You can set up the Skyrover to work like this (there’s a gyro+computer product called PicLoc you can use for this), but you need to provide the extra gyros and hook them up yourself. Not difficult, but you need to decide whether the effort is worth the slight improvement.

But even with the standard arrangement of the Skyrover and Mikrokopter, the Skyrover is amazing at absorbing vibrations and stabilizing the camera. I’ve shot stills at dusk at 1/125 second and got results that were consistently tack sharp. Can’t do better even on a tripod.

For video, the results are also quite good. The Skyrover mount compensates for helicopter movement quickly, smoothly (important for video) and with lots of torque for heavier cameras. The current version of the mount will accomodate a camera body that is 5.75 inches wide. This is wide enough for most small and medium size DSLR’s. Though it’s not quite wide enough for a Canon 5DII. My understanding is that a wider carriage version of the mount will be available to handle larger cameras (Spring 2011 time frame).

Equally important, the Skyrover is mostly made of aluminum. It can withstand hard landings and outright crashes, often protecting the camera from damage. At 600 grams, you can lift it easily with an octocopter or hexacopter suitably powered (we’ll explain what this means later as well). I prefer aluminum to carbon fiber. Carbon fiber can shatter in a crash. Aluminum bends. So, you can bend the aluminum back and (hopefully) keep flying.

To be continued…

What’s It Really Take?

Back in November 2009, I posted an article about choosing (radio controlled) helicopters for aerial photography. At the time, I was looking for the cheapest way to get professional quality results for both still and video. Back then,  you’d need about $3k worth of helicopter (or more). You’d also need to hire a pilot, or spend a year or more likely two years learning to fly it yourself.

Well, all that’s changed. There are new helicopter designs with ever more sophisticated electronics. The new designs are cheaper, more stable, easier to fly, stay in the air longer, and are safer and easier to repair than “conventional” helicopters. And as digital cameras get smaller and lighter, the loads placed on these helicopters are reduced. This makes it possible to use smaller, less powerful helicopters to get the job done. Sound good? Here are the details… read more »

The Vision

This is a story that I find inspiring.  Since it’s also about photography and space, I find it even more inspiring. It’s about two MIT students who wanted to photograph the “edge of space.”

It started when Oliver Yeh had a vision. He wanted to see the curvature of the earth and the blackness of space from high up in the stratosphere.  Many of his friends thought he was crazy.  Not Justin Lee. Lee accepted the vision and made it his own.  So together they set out to accomplish the task.

The Ingenuity

Like others before them, Yeh and Lee decided to use a weather balloon  filled with helium  to lift a small camera up into the stratosphere.  They bought a 300 gram latex balloon online.  Balloons are capable of reaching altitudes of 20 miles or more. Unlike others before them, read more »

Too Many Tools, Too Few Buttons

With each release of Photoshop, new tools and filters are added, as you would expect from a product that is continually being refined and improved.   Sometimes the consequences of this growth are changes to the user interface that actually make Photoshop a little harder to use for those of us who were used to the previous version.

For example, in CS3 the tool palette has 24 buttons for 59 tools.  That’s a lot of tools that aren’t in plain view.  So if you are a casual user of Photoshop or you’ve just upgraded to a new version, you’ve got some hunting to do.

Exploded View of All Tools

To make it easier to find the tool you want, we’ve created a summary sheet read more »

Problems with MP4 Importing

In a previous post, I discussed difficulties I encountered while exporting MP4 files with Final Cut Express 4.0.  In this post, I will discuss difficulties I encountered while importing MP4 files with Final Cut Express. In particular, I noticed that FCE sometimes truncates mp4 clips during import.  I found that I could import 20 megabyte mp4 clips just fine.  But clips just over 30 megabytes in length were shortened.  They were truncated so that they terminated early.  I couldn’t find a setting in the user or system preferences that would allow me to import longer mp4 clips without truncation.

MPEG Streamclip to the Rescue

The solution I found is to split long mp4 clips into shorter clips, each of which can be imported into FCE successfully.  You can put the clips back together once they are inside FCE by dropping them into the same sequence.  The tool I used to split a clip is a very nice freeware conversion and editing utiliy called “MPEG Streamclip.”  You can download MPEG Streamclip at www.squared5.com.  It is available for either Macs or PCs.

Click by Click Solution read more »

New to Final Cut Express

I’ve been teaching Photoshop to photography students for about 12 years.  When a recent student asked for training videos to supplement the instruction, I decided it was time to make some.  Not knowing what I was getting myself into, I went out and got a copy of Final Cut Express 4.0.  And so the fun begins.

Final Cut Blurries

After reading a few sections of the manual that comes with FCE, I was able to assemble a few mp4 video clips into a sequence.  However, when I tried to export the sequence to get a final video result (also an mp4), I hit a roadblock.  The resulting video was quite blurry and in a dynamic way.   That is, text in the video would sometimes be crisp and sometimes become a blur.  It was as if someone was pouring water over freshly painted watercolor. The blurriness would flow around the image.   I assumed that this was some kind of compression artifact, so I tried using different parameter settings during the export to fix the problem. No luck.  I finally concluded that there must be a bug in FCE’s processing of mp4 files.  So, I tried a different output format.  When I chose the Quicktime Movie format (an mov file), things started to work much better.  With the right settings, I was able to get clean, crisp output.  In this post, I’ll take you through the settings that I found to work, so you can get high quality exports without a fuss.

Click-by-click Solution read more »

Bad Weather, Good Photos

It’s snowing here today.  Such stormy weather can provide opportunities for beautiful and unusual shots. So, I was very eager to get out and see what I could find.  However, there’s nothing worse for your camera than getting either water or sand inside it.   So as I was getting ready to go out and take some pictures,  I looked around the kitchen for something to protect the camera.  Unfortunately, I discovered that I was out of zip-loc bags.

Zip-loc Raincoat

A large zip-loc bag can make an acceptable raincoat for a DSLR or similar camera.   The camera goes inside the bag, and the lens pokes out the opening of the bag.  You can snug the bag around the lens barrel with a rubber band, or sometimes the zip-loc itself will hold.  But what do you do if there are none around? read more »

Smallest Cameras for Aerial Photography

I’m always on the lookout for simple and inexpensive ways of taking pictures.  The term ‘inexpensive’ usually doesn’t go with aerial photography.  However, I recently came across two new products that are moving in the right direction. They are the HD Hero Camera from GoPro, and the FlyCamOne 3 from the Acme game company.  This is neither a preview nor a review of these two new products.  Rather, this post is a quick announcement with some notes about their capabilities.  I will write full reviews after I’ve had a chance to try them out.

Small, Light Weight and Good Image Quality read more »

Aerial Photography: The Essential How-To Guide by Greg McNair

The Bird’s Eye View

Have you ever wondered what the world looks like from a bird’s perspective?  Have you wondered how you might get a small, or maybe not so small, camera airborn to find out?     The book Aerial Photography: The Essential How-To Guide by Greg McNair shows you how to get started with remote controlled (unmanned) aircraft capable of carrying cameras.    I recently bought a copy, which I ordered from his website www.aerialphotobook.com for $49.95.  This post is a brief review of McNair’s book.

The Dreaded AP Mosquito read more »

Rude Awakening

When my D3 first arrived, I had been using a D2x for 2 years.  I never noticed the D2x’s autofocus because it worked so well.  It faded into the background of my attention.   Expecting to have the same experience with the D3, I took it out of the box and brought it with me to a friend’s wedding.   I was seated among the guests right on the aisle.  It was still daylight, so the chapel had adequate lighting.  When the bridal procession began, I expected to get some great shots for my friend, the groom.   As the procession was moving straight toward me, I had only a few seconds to get a shot.  I confidently picked up the camera, framed and pressed the shutter.  Nothing happened.  I noticed that it was in single shot mode (S on the front switch) and realized that the shutter wouldn’t trip unless the focus was spot on.  I immediately switched it to C.  My last chance.  I reeled off a few frames, but all of them were out of focus.  What had gone wrong?   Of course, I switched to manual focus, but that moment was lost.  Fortunately, I wasn’t the hired photographer that day. read more »