Motion Control Camera

I'm considering getting in to microcontroller programming and have a
project I want to work toward.
Any suggestions on how to build a decent motion control camera rig? I
want to play around a bit with greenscreen model shots, but mostly I
want something to perform smooth repeatable camera moves. I'd start
out with two axis and move up from there.
My concerns are the following.
-Learning (as opposed to programming the move each time as you would a
CNC lathe)
-how to get home position or position feedback
-Memory (Do I store only angle information or angle AND acceleration?)
-physical layout
-Microcontroller power and ease-of-use
Ease of use dictates that the rig be operated by joystics operating the
axis (pan/tilt/up/down/forward travel/reverse travel). I could
probably figure out how to use a Basic Stamp reading pots and operating
some geared-down stepper motors to get this functionality, but how do
you store the information? How fast do you need to poll the joystics
and set the steppers for smooth movement? How much memory is required
for, say, 2 minutes of data?
I think the layout should follow the camera usage as much as possible.
So, no boom and no arm. The camera should probably be on a track with
counterweighted movements up and down a central shaft, or series of
shafts.
Finally, what's a good platform to use for someone who knows a very
little bit about a lot?
Basic Stamps are easy, but I'm concerned about cost and the power of
the Basic programming language. I REALLY like Basic Stamp's
all-inclusive starter kits, though.
Ooopics look better, but cost is a problem (I'd rather fry a $5 pic
than a $70 daughter board) and no nifty starter kits.
Proton Basic looks promising, but is expensive and no all-inclusive
starter kids with books to hand-hold you through the learning process.
And that's just the PIC side. There's Atmel and some Rabbit thing too.
Along with Lego's Mindstorm.
Thanks for your help!
P.S. I HAVE done a motion control scene already! I put my camera on
the rotating platform of a stretch wrapper. The movement slows and
stops in roughly the same place so I videotaped myself three times at
three different locations and composited them together. The result is
the camera panning over one of me, then stopping on two of me sitting
at a table. That was fun!
Reply to
MrMJPEG
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UGH..
1) MoCo Two Modes. Record/edit/playback Moves are taught, editable on a per axis basis Moves can be played back slowly Moves can be smoothed
Keyframe Keyframes are selected 'tweens are calculated lead in/lead out slope is calculated
2) Microcontroller There is a lot to it. maybe you can use the basic stamp as an intelligent LCD controller.
3) Repeatability If you truly want to do mattes, you need frame accurate motion control. You need to play the scene back exactly every time in relationship to the beginning of a captured frame.
4) Memory Lots...
If I were building it, I would use a Gumstix doing user IO on a nice LCD, with an IsoPodX doing motor control and timing.
Reply to
blueeyedpop
Wow! Since I'm looking to learn by doing I think the Gumstix and IsoPodX are beyond my reach (financially and knowledge) just yet.
I hadn't thought about editing. That's a good point. Ideally, it would record the moves to a file on a USB or flash drive which could then be edited on a PC. (or, for real pie-in-the-sky it could output coordinates usable by 3D animation programs for use in virtual sets. But, I realize matching the lens makes this problematic).
Repeatable almost frame-accurate motion is a must. I realize with a home video camera I'm never going to get it exact (although, model shots could be done frame accurately with my EOS digital and long exposure times with some sort of shutter attachement). Ultimately I'm looking to be able to do twin effects with a moving/panning camera.
Reply to
MrMJPEG

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