Dynamic Perception Motion Control

In my last blog entry I gave an overview of my homemade time-lapse motion system called VEGA-T. After spending time with it and learning a lot, I decided to upgrade to a Stage Zero system by Dynamic Perception. In doing so I was going to gain a lot of features and hopefully eliminate a few issues I had on my own.

The requirements I had when I built VEGA-T were still necessary for the Stage Zero system though, Four feet sections, expandable to 8 feet and being travel/hiking friendly. I also wanted some more functionality though, the ability to traverse steep angles with the dolly and the ability to do a shoot-move-shoot sequence (SMS). This allows for the cart to stop moving to take long exposure shots at night, then move again until the next programmed stop and shoot.

Dynamic Perception’s standard Stage Zero Kit comes with a six foot 80/20 #1030 T-slotted rail. This was too long for traveling for my situation so after talking with them I decided to buy two four feet sections of rail from Amazon. It’s the exact same as they sell, just a different color and length. To join the two pieces together I also purchased some joining plates to go on top/bottom of the rail to keep it secured as shown below. These are easily removed for traveling.


Joining Plates

Since I was not getting the full bundle from Dynamic Perception I decided to just get the bare hardware setup and assemble my own MX2, the brains behind their system. This saved me a bit of money that I ended up spending on their Limit Switch Kit which you can plug into the MX2 to program different options for when the dolly hits the end of the rail, such as stop the time-lapse, another nice feature to have that I didn’t have before.

Fully assembled MX2 without enclosure.

Once getting the setup up and running I did run into a few hurdles that I’ve had to work around. Although the join between the two pieces of rail is fairly smooth, a noticeable jump or twitch can often be seen in playback of the time-lapse. With patience and know-how this can be mostly corrected in post but it’s still frustrating to deal with when you are hoping for pixel perfect shots. I can’t fault Dynamic Perception for this though as doing a two piece setup isn’t their preferred setup.


Time-lapse at Ice Lakes in Colorado

This is probably my biggest problem with the Stage Zero, controlling the speed of the dolly across the track. The speed is set by specifying the movement in inches per minute. Originally it sounded like a really simple and good way to control how long it should take to traverse the rail. After hours of testing it never comes out right. There is a calibration setup to run on the system but I’ve seen little change in results afterward. Sometimes it’s slow, sometimes it’s fast. I’m not talking a difference of seconds either. I regularly experience a major difference of 10 minutes end to end vs. 20 minutes when only adjusting the speed by +/- 0.02 inches per minute. This can be very disheartening when you have a great shot and it only shoots for half the time you were hoping for and you end up with a very short time-lapse. There are many factors that can greatly change the real speed that it moves including battery levels, weight, angle, direction of travel, tension of the belt, etc. I’ve made my own conversion table that I keep on hand when we shoot to give myself a better idea of how long the shot actually will last for.  With practice it’s close but really it comes down to a guesstimate.


Time-lapse at Ice Lakes Trail in Colorado

One other thing worth mentioning is that for whatever reason, it seems the guide pulley bearings aren’t designed well enough to handle the belt slack. Without tightening the belt to the point where the motor is heavily strained, the belt will often drift up or down and cause binding and attempt to jump off the main pulley. As it does this the dolly slows with the added tension and ruins the shot. I’ve had to modify my dolly to guide the belt better to keep this from happening. I don’t believe this problem to be caused by my longer rail as I often see much longer custom setups by Stage Zero users.


Time-lapse at Voas Nature Area in Iowa

Overall though, the system works well once you have a handle on it. I plan on purchasing a 6 foot rail section from Amazon soon to use when I’m not planning a long hike to avoid the center joining issues. I am also going to work on a better guidance system for the belt to prevent it from binding on the pulley.

Pro : Any angle & direction you can think of
Pro : Shoot Move Shoot (SMS) for long exposures
Pro : Ability to purchase parts from other sources

Con : Unpredictable speeds
Con : Lacks proper belt guidance
Con : Cost, for what you get its pricey

Below are a couple samples and tests of what we shot on the Dynamic Perception Stage Zero system this spring. We shot a lot of time-lapse footage on this setup over the summer in southern Colorado. We are hoping to put everything together into a reel later this Fall.

Sunset testing with vertical setup on Stage Zero
Forest Floor with Stage Zero

We also should be receiving the next investment into our time-lapse equipment, the eMotimo TB3 Black. I’ll write something up on it as well once we’ve gone through it.

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