LED Ring Colour

[MattInAHat]

For vision processing, what would you folks recommend as a colour of LED light/ring?

[engunneer]

Green or white. (violet or orange can be ok)

there is a lot of red and blue around the field, you don't want to accidentally detect signage.

[billbo911]

Honestly, with a properly calibrated camera and vision processing code, any color is "the right color".
I would choose what you have easy access to, and/or what looks best on your robot.

[stingray27]

Originally Posted by billbo911

Honestly, with a properly calibrated camera and vision processing code, any color is "the right color".
I would choose what you have easy access to, and/or what looks best on your robot.

Agreed. Although, choosing white light may be the easiest cause you can filter out all light intensity below pure white light which is what you would get from the bounceback beam of the retroreflective tape.

[Hallry]

Originally Posted by billbo911

Honestly, with a properly calibrated camera and vision processing code, any color is "the right color".
I would choose what you have easy access to, and/or what looks best on your robot.

Emphasis mine. Just remember, functionality > aesthetics

[Steven Donow]

Originally Posted by Hallry

Emphasis mine. Just remember, functionality > aesthetics

I agree.

Those of you that know me personally, know I'm a huge freak when it comes to the visual appearance (nothing looks as awesome as fluorescent orange spiral wrap...), but I don't mess with the vision processing. Knowing that green is one of the best colors, I don't care how much it clashes with red/orange, it works significantly better than other colors, so I say let the green shine!

We purchase our LEDs from superbrightleds.com, specifically using Angel Eyes. These are also what's included on FIRST Choice. We usually use two, 60 mm and 80 mm, but are looking into adding a 100mm this year.

[fovea1959]

we're finding that the orange we had is not popping out as quite so orange all of a sudden...

[Jared Russell]

Keep in mind that many/most digital cameras actually use a Bayer pattern on their CMOS imager. This means that the cameras have twice as many sensing elements for detecting green light than red or blue.

Does it make a significant difference for our application? I am honestly not sure, but that was our thinking behind using a green LED last season.

[Lightfoot26]

We used a ring of 96 IR leds and an IR filter modded onto the Axis Cam last year, it was legal under the custom circutry rules and worked like a charm... White squares against black background.

[Jon Stratis]

Personally, I would stick away from white, just because there's already a lot of "close to white" light in the area, coming from venue lighting that might interfere. Yes, with proper filters you can get rid of it... but you won't be sure how good it is until you're on the field. Using a specific color, like green, should help to eliminate that problem.

[billbo911]

Originally Posted by Jared341

Keep in mind that many/most digital cameras actually use a Bayer pattern on their CMOS imager. This means that the cameras have twice as many sensing elements for detecting green light than red or blue.

Does it make a significant difference for our application? I am honestly not sure, but that was our thinking behind using a green LED last season.

Originally Posted by stevend1994

... Knowing that green is one of the best colors, ...

The reason camera's emphasize green is because the manufacturer is trying to mimic the human eye's sensitivity. Knowing this means green takes less light to reproduce the same signal. Does that make it "best" or "better"? That is debatable.
Again, if you properly calibrate your camera and vision processing, any color is fine. So, just use what you are comfortable with.

[Orion.DeYoe]

Originally Posted by MattInAHat

For vision processing, what would you folks recommend as a colour of LED light/ring?

Green works. Definitely not red or blue. I've heard good things about purple as well. We got our ring lights here: http://www.superbrightleds.com/morei...ent-lights/49/

[JesseK]

I'm not the vision guru on our team, but the vision team is using an Orange LED strip. Not sure why.

[Nick Lawrence]

Originally Posted by Orion.DeYoe

Green works. Definitely not red or blue. I've heard good things about purple as well. We got our ring lights here: http://www.superbrightleds.com/morei...ent-lights/49/

Blue works just fine. See 254's robot last year. Their camera tracking works well.

-Nick

[rl1806]

We used a green LED ring from superbrightleds.com last year. Many teams at the Greater Kansas City regional used green LEDs and some used red or blue LEDs.

I think how the programmers setup the vision system has more to do with how successful the vision system is.