Attack of the Panoramic Robots! or, The Search for a Motorised Panohead

For several years now, I've wanted to be able to shoot remotely-operated panoramas. Specifically panos from elevated positions, say 4-6 metres above the ground.

'Wait', I hear you say - 'what about pole panoramas where you stick a camera on the top of a long pole and turn it around?'. A great idea, but it doesn't work in small spaces due to positional difficulties. And I often shoot in the evening, with shutter speeds in the seconds - a challenge when it comes to poles that tend to, um, wobble a bit...

The unlikely solution? LEGO Mindstorms NXT.

First steps towards a Panobot

The ideal requirements:

• Motorised panorama head capable of shooting multi-row spherical panos.
• Remotely operated for use on tall stands or in confined spaces.
• Capable of carrying a dSLR and large lens.
• Flexible programming.
• Tethered control from a laptop so that I can control both camera and head at the same time. Oh, make that a Mac laptop as I couldn't afford an extra laptop as well.
• Relatively affordable - the PixOrb from Peace River Studios is a great piece of kit, but when I was looking a couple of years ago the Dollar was stronger against the Pound, and it would have cost in the region of £5000...

Given the price of the PixOrb (which fills all the other criteria) and being a keen tinkerer, I looked at building something myself. Either from scratch using aluminium profile, stepper motors and a BASIC stamp controller, or hacking one of those motorised telescope mounts. Further investigation proved both routes to be far from ideal, though. A big enough telescope mount such as one of the larger Meade scopes was looking a bit expensive given the extra work involved, plus all the u-frame models had huge bases which would obscure a large area of the nadir. Scratch-building was out due to the amount of time involved in learning about stepper motor controls and programming stamps.

Hope Looms...?

Then a new product from Germany hit the market: the Karline Rodeon Pro, distributed by Marc Kairies. It could (just about) take my favoured combo of a Canon 10D plus Sigma 12-24mm lens, could be programmed for different lens set-ups and had an option for a radio remote to set it going. After looking at the time and money involved in building or converting something myself the Karline Rodeon actually worked out cheaper, even at a couple of thousand Pounds Sterling.
As I had a major architectural commission on the way, I ordered one.

Note the aerial on the top.

Unfortunately the early version of the head that I received wasn't impressive, with a lot of slack and poorly thought out controls. It wasn't possible to program in zenith or nadir shots, or to control exact angles for columns or rows, and as I already knew before buying, there was no option for tethered operation. So it went back to Marc after the commission, who kindly agreed to change it from a purchase to a rental period.

One of the resulting panoramas, shot from about 4 metres up. Due to the lack of zenith or nadir shots, this is made up from three rows of nine images, rather than my standard 2x8 plus up and down.

So plans went on the back-burner - I had other fish to fry in the meantime with a series of busy commissions.

The newer modular version of the Karline Rodeon is much better than the one I used, and uses Bluetooth communication from either a PDA or a Windows PC.

New Ideas

Fast-forward to this Spring. I'd already come across LEGO Mindstorms kits for building LEGO robots, but had heard about the new all-singing all-dancing new version which was on the way later in the year. After some idle curiosity lead me to read through the specs, I realised that it would be perfect for building my own motorised panohead:

• Powerful servo motors with built-in position sensors - the older versions required both a motor AND a sensor for each axis of movement.
• Bluetooth connection, both from a computer and eventually from a PDA or mobile phone.
• PC and Mac compatible programming software.
• LEGO's legendary speed of construction when building a prototype.

After some thought, I decided to dig out the old plans for a self-made head and pre-ordered a Mindstorms NXT kit. Along with a bunch of Technic LEGO going cheap on eBay.

Then I waited impatiently for the shipping date - it was due to turn up during the PanoTools meeting in Bath. As it was, the shipping date slipped a few times, but it eventually turned up. A couple of evenings later, and I'd built and programmed the first prototype.

The NXT Panobot mk.0

This is not truly functional as the frame is not strong enough to take a decent size camera (maybe a compact). But it works well as a test bed for testing the programming side of things. Currently it has a single 'static' program - take a row of six shots and then the zenith. One motor for yaw, one for pitch and the third will fire a remote release for the camera. It already has a few more sophisticated aspects programmed in - ease in and out on the movements so that it doesn't jerk too much, pauses between moving and firing, and it returns to the starting position afterwards.

Panobot mk.0 in action (5MB MPEG4 movie)
Note that the third motor (shutter release) currently just spins in mid-air.

Back to the Future...

• Build a robust U-in-U structure using aluminium profile with a big bearing underneath.
• Geared down LEGO motors will move the main structure via toothed belts and pulleys - LEGO axles just aren't up to the punishment inflicted by a couple of kilos of offcentre camera gear...
• Look at some form of counterweight to the camera, so that the pitch motor doesn't have to work so hard.
• Bluetooth will currently connect to either a computer or another NXT set, so one can control it 'manually' by downloading a new program for each movement. Coming soon, however, is software that will allow you to interact with the NXT brick via your mobile phone - hopefully this will mean that you can set parameters and trigger events via the joystick and keypad.
• Dig into the Bluetooth SDK that is freely available, to see if I can directly contact the running program - then it would be relatively easy to build a nice control interface for full control - maybe even integrating a live viewfinder feed via a webcam.

'Bye for now,

Ian

P.S. LEGO®, Mindstorms and NXT are registered trademarks of The LEGO Group.