AotPR part 8b - 360 Degree Panning Timelapse

I managed to get out again on Saturday evening. This time the battery didn't run out...


Click to see larger version.

So, this time I managed to get a full 360 degree timelapse movie (plus a bit extra for emergencies):

Click to see video (QT7, 8MB).

There's some odd lightening and darkening going on from the auto-exposure, and the transition at the end of the loop is harsh, but it's got promise.

It's also a bit jerky in places - I think that the current trigger mechanism is a bit unreliable with this many shots:

This design depends on the right tension in the rubber band* - too little and it doesn't trigger the shutter, too much and it never goes below 'half-pressure' which means that you never get a preview on the screen and appears to run down the battery faster than normal. Possibly causing the battery problems during the first attempt...

As a result, I've started redesigning the trigger mechanism so that it works on a simpler rotary motion with no arm on the motor but with stronger rubber bands - normally the rubber bands are under almost no tension (and the camera goes back to normal), after a 180 degree rotation of the motor the bands are under more than enough tension to trip the shutter.

Shutter open - almost zero tension on shutter release.

Shutter closed - high tension on shutter release but almost no tension on motor.

There's an added bonus that the shutter can be held down for long periods without burning out the motor. This will be particularly useful for bracketing - holding down the shutter on a Canon dSLR set to motor-drive and bracketing will take the three shots and then stop shooting until the shutter is released and pressed again.

Ian

P.S. I found some interesting stuff on a Canadian photoblog covering some of the same ground but with single images. The Flash 'object movie' version is nice: http://wvs.topleftpixel.com/archives/photos_landscape/060828_1662.shtml

* If it ain't got a rubber band, it ain't a proper contraption!