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Built a DSLR zoomer/time lapse focus control

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mvf
Posts: 786 - Karma: 1,581
For a year long project for my 4th year of engineering physics at UBC, I decided to build a motorized controller for the zoom ring of DSLR cameras. The goal was to also be able to use it for racking the focus and zoom through out time lapses (used an Arduino microprocessor to take tiny steps between shutters).

The zoom control still has some issues, as there is some play in the mechanism that results in jerky zooms. Hoping to get it worked out in the next month, although school is out for the summer.

The time lapse control seems to work beautifully.
Here's my first test for racking the focus through a time lapse, let me know what you think:
Apr 20 2013 7:36PM
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lamppost
Posts: 277 - Karma: 201
not even kidding, that was one of the coolest things ive seen in videography
Apr 20 2013 7:47PM
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mvf
Posts: 786 - Karma: 1,581
Stoked you think so


Here's the actual first test I did, but we were actuating the focus ring every 8 pictures because we had not figured out how to make our servo take micro-steps yet. Since then we did some sneaky coding to take smaller steps and are now able to actuate the focus ring after each picture is taken.
Apr 20 2013 7:58PM
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loganimlach
Posts: 5132 - Karma: 14,061
sick!
Apr 20 2013 8:00PM
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erikK
Posts: 3245 - Karma: 2,328
awesome! can we see some photos of it?
Apr 20 2013 8:16PM
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mvf
Posts: 786 - Karma: 1,581
Sure:

Click for larger image

Laser cut gear on the motor, and a ring gear on the lens that was originally designed to be used with a follow focus unit. The motor is a special type of servo that can turn 2.5 full rotations.

A servo is just a DC motor that knows its position, so you can tell it to go to, say, 120 degrees. Normal DC motors you just say GO at some speed, not go to some place. However standard RC servos usually only rotate 180 degrees. I needed one that would turn more rotations so we could gear down its rotations and turn each step of the servo into a much smaller step of the focus/zoom ring.



Click for larger image

We put slots in the base plate of the device so we could:
a) Use this on lenses of multiple lenses and
b) Move the motor forward or backward depending on if we wanted to actuate the zoom or focus ring


Apr 20 2013 8:27PM
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Mkvackay
Posts: 1903 - Karma: 5,465
that was pretty cool
Apr 20 2013 8:34PM
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speedin
Posts: 731 - Karma: 131
Dude really colol man. For time lapse autofocus lens seem the way to go, but for video, manual focus lenses are much better. (From my research)
There are better rc servos for this application, including 360 degree servos. Check this out.
http://m.instructables.com/id/Arduino-Lens-Controller-Synchronized-ZoomFocus-/
This guy has it perfected pretty well. Notice how he also uses a servo for the focus as well. He sets ur end points on the wii controller for the zoom and focus. He looks to have all the coding done for the arduino. I would take a solid look at this build.
Apr 21 2013 2:15AM
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Mag
Posts: 8155 - Karma: 14,809
Threads, sounds awesome
Apr 21 2013 7:05AM
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De-Clan
Posts: 1920 - Karma: 3,696
That was dope
Apr 21 2013 10:11AM
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mvf
Posts: 786 - Karma: 1,581
My servos do 900 degrees of rotation.

I originally tried to build a design that could attach ONLY on the lens, not to the body at all.
This took months of fucking up and finally I resorted to building the final design in about a week (deadline for the class was coming up).

The design you posted is a copy of this:
https://www.youtube.com/watch?v=cCFjkqwq-Xk

I was going to copy this design as well but wanted to build something that did not require tripod rails.
Apr 21 2013 2:26PM
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brian.walker
Posts: 885 - Karma: 1,160
That was really sick! Great job!
Apr 23 2013 2:03AM
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speedin
Posts: 731 - Karma: 131
Actually, the design is not a copy of what you posted. If you read through the build, you will see that the whole controller is controled by a arduino micro controller. This eliminates all the massive bulky equipment needed in your reference.
The build is actually quite impressive. You could easily modify the design to attach it to the lens instead of the tripod rails. It is all in the ardunio, and open source coding. Even if you don't change your design you check out his coding, he did a spectacular job.


Apr 23 2013 11:54AM
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speedin
Posts: 731 - Karma: 131
After look at the video of the varizoom, I have come to the conclusion that it is very very very over engineered, huge controllers, all very bulky. Not to mention that like most pro cinema gear, is very over priced.
They took a simple concept, and tried to make it into something that is way over enginered, in hopes of justifying the price tag.


Apr 23 2013 11:58AM
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mvf
Posts: 786 - Karma: 1,581
Believe me, I tried. It has nothing to do with the Arduino. The Arduino just controls the motor speed.

The coding was easy, it was was making a mechanical system that could transmit enough torque without stalling. My previous design (to have the entire component attached to the lens) had too much play. I'll upload some pictures of it later.

As for copying the Varizoom, that guys is the exact same but simplified.
Identical idea:
Rotate motor assembly (nearly identical motor assembly) around the rails to engage the pinion (driving gear) teeth with the ring/lens gear.

His was 3-d printed, Varizoom's was machined/molded (so it seems). Fuck they probably run an Arduino too, just have it hidden by all their extra shit.
Apr 23 2013 12:23PM
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Kretzschmar
Posts: 6705 - Karma: 98,258
this is sick!!!
Apr 24 2013 2:04AM
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sveinung
Posts: 105 - Karma: 74
Dope!
Apr 24 2013 1:32PM
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speedin
Posts: 731 - Karma: 131
Many options for torque. Servos, stepper motors, brushless motors...ect
The arduino is cool because its soo small, it really is the definition of microprocessor.


Apr 24 2013 5:30PM
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mvf
Posts: 786 - Karma: 1,581
Yes.

Used a servo because:

a) Easy to communicate with using Arduino
b) Wanted to have smooth zoom motion for zoom control during video mode. This was originally designed to be ONLY for zoom control, not time lapse at all. Just turns out the time lapse control is a sweet function too.
Apr 24 2013 5:33PM
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NMMedia
Posts: 982 - Karma: 1,700
This is really cool, props to you for building this. I wish I had something like this but I dont have the money or the knowhow.
Apr 25 2013 9:07AM
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