Lighting up the vison targets?
 

This is my first year using the camera tracking software. I recently purchased this as was suggested by this thread. Upon receiving it and turning it on, it seems to be too wide of a viewing angle to light up the targets enough.

Have teams need to light up the targets in prior years? If so, was that amount of light enough? If it isn't, is there an easy way of focusing the light?

Any general suggestions for camera tracking?

Thanks a ton!

Re: Lighting up the vison targets?
 

I'm using the one from first choice (which I think is the one you bought), and it works fine at long distance (field length) for me

Re: Lighting up the vison targets?
 

You don't really want to focus the light to tightly in one direction. It needs to illuminate the entire field of view of the camera in order to be most useful. The spread from the LED chips on those light rings is just about right for our application.

Re: Lighting up the vison targets?
 

What leads you to determine that it is not enough light? Did you look through the center of it or mount it around the camera lens?

Greg McKaskle

Re: Lighting up the vison targets?
 

I have not done any work with the camera with the light mounted yet, but I plugged it in, and it only gives the tape a dim green (color I bought) rather than the bright color I expected. I didn't know that it is enough for the NI software.

Re: Lighting up the vison targets?
 

The targets are made of retroreflective tape. When viewed from an angle, it doesn't look like the LEDs are putting out much light. But try looking through the hole in the center and you will find the targets light up like Christmas trees.

Re: Lighting up the vison targets?
 

We also bought the FIRST choice green LED ring. At first we thought it wasn't bright enough because the target only looked a little brighter with the LEDs on, but when we extracted the green color plane from the image the target was well illuminated and easy to find (with a vision algorithm). Don't write off the green LEDs until you've done that.

Re: Lighting up the vison targets?
 

Micah,
The LED ring is intended to mount around the lens of the camera. The reflected light from retro-reflective tape is pretty impressive.

Re: Lighting up the vison targets?
 

We did a little test to see how far off axis you could be and still see the light being reflected back to the source. We wanted to know if the color could be polluted by a robot right next to yours with a different color light. We found that as little as 6 inches off axis was enough to SIGNIFICANTLY reduce the reflection. By 12 inches, it was gone!
Look through the center of the ring, where your lens should be, and you will see the light!

Re: Lighting up the vison targets?
 

Wow! That makes a big difference! I didn't even think about looking through the center.

Re: Lighting up the vison targets?
 

Well our team bought a strip of led light that is flexible, the problem we had was the light source has to be as close to directly inline with the camera as possible, the retro reflective reflect directly back from where it is shined, so the close to your lens the better results youll get, so our team has the leds rapped right around the camera

Re: Lighting up the vison targets?
 

I was confused by this, because I initially thought that this tape would reflect in a broad bell-curve-shaped distribution centered around the angle of reflection of the light source. This came from a poor understanding of the meaning of retro-reflectivity.

Then I read this writeup about the construction and physics of retro-reflective tape: http://dr650.zenseeker.net/ReflectiveTape.htm

Re: Lighting up the vison targets?
 

Our team (78) was able to secure, from ebay, some surplus green traffic light LEDs. They provide tons of light, (don't look at them...) but you may have to contend with an overheating problem... we almost melted through a camera... Its about 9 lights on a square panel, VERY USEFUL!!!:) :) :) :)

Re: Lighting up the vison targets?
 

You may have an issue with blinding your alliance partners. Remember this...
[R08]
Robot parts shall not be made from hazardous materials, be unsafe, cause an unsafe condition, or interfere with the operation of other Robots.
Examples of items that will violate this rule include (but are not limited to):
A. Shields, curtains, or any other devices or materials designed or used to obstruct or limit the vision of any drivers and/or coaches and/or interfere with their ability to safely control their Robot
B. Speakers, sirens, air horns, or other audio devices that generate sound at a level sufficient to be a distraction
C. Any devices or decorations specifically intended to jam or interfere with the remote sensing capabilities of another Robot, including vision systems, acoustic range finders, sonars, infra-red proximity detectors, etc.(e.g. including imagery on your Robot that, to a reasonably astute observer, mimics the Vision Target)

Re: Lighting up the vison targets?
 

We refuse to put an ugly green light on our red and black robot, so we went with the amber light and it is working very well for us.

-Brando