Retro Reflection Vs. Flash Photography...

[Joe Johnson]

Has anyone seen the pictured of the goals when they are shot with a flash camera?

The retro-reflective tape puts some ghostly images on the screen.

I wonder if this will cause TV crews any problems.

Joe J.

P.S. I KNOW I saw flash photos from some mini-competition held this past weekend somewhere, but I could not find the photos again so that I could link to them. Anybody know where I could have seen them? Do tell... JJ

[Matt Leese]

You may be talking about these two:
http://www.chiefdelphi.com/forums/pi...rrow=4&trows=3
http://www.chiefdelphi.com/forums/pi...rrow=4&trows=3

All I know is that the pictures were taken with a digital camera with flash. I can find out what model if anyone's really interested

Matt

[Clark Gilbert]

Here is a pic of the goal "glowing".

I believe this picture was taken with a flash while using a disposable camera, then my friend had them put on a disk.


(If anyone is wondering whats the pic of, its something we do at TechnoKats every year to get a feel for the game..normally we just call it the "Human or People Game", pretty darn fun if u ask me )

[RebAl]

It will not be a problem for video because it does not use a flash nor a light near the lens so it wont reflect directly back, as for professional cameras - the flashes they use are much further away from the lens then the cameras we have, thereby increasing the angle of the flash and not having the flash thrown back as bad to a camera like that.

[Anthony X.]

You have to admit the glow looks cool though!

[WakeZero]

Hehe, I think it looks better that way

[Joe Johnson]

I think pretty much any flash photography (disposable camera or pro set up) is going to have the ghosting on it.

Also, I don't think that distance is going to matter much. That is the thing about retro-reflective surfaces. Think about how easy it is to make a stop sign glow. Same thing here I think.

As to video crews, I think if they use a light source they will have problems. Not all use an additional light source if they do, I think it will show the ghosts.

Anybody able to confirm or refute these claims?

Joe J.

[Jason Rudolph]

Well, as far as photographers go, I think they will have a problem no metter what. The thing is, that many proffesional flashes, while further away from the lens, also zoom with the camera itself. And, as Woddie pointed out, the thing about retroflective tape is that it reflects at all angles. So, while helping in reduce red-eye, having the flash further away wont help much in preventing the reflection of the tape.

As far as video goes, it might not be as much of an issue, as the lights used as external sources are not as bright as a flash is. It might be an issue, but I am sure that the proffesionals know ways around it.

I would be more worried about your amateur pictures by people on your team than by the proffesionals.

[ahecht]

Originally posted by Joe Johnson
Also, I don't think that distance is going to matter much. That is the thing about retro-reflective surfaces. Think about how easy it is to make a stop sign glow. Same thing here I think.

Distance to the goal doesn't matter much, but distance between the flash and the lens (or observer) matters, since retroreflectors focus the light at the point that it originated from. A professional photographer with a remote flash would not have any trouble at all.

[Joe Johnson]

It depends somewhat on the angle between the incoming flash and the camera lens but if the distance is great enough to get the angle high enough, a remote flash should cause no problems at all.


Joe J.

[Tom Fairchild]

I watched the kickoff on NASA TV and the tape was no problem at all. Wouldn't think that it would be any different given the fact that the fields are VERY well lighted and TV cameras do not need much extra light anyways.

~Tom Fairchild~

[XRaVeNX]

Ya. I love the glowing. Looks very very cool. The reason this happens is that the reflective tape reflects light directly back at it's source. So, when the flash goes off, all the light bounces off the tape and back into the shutter.

We have some pictures of this glowing.... it's in our photoalbum... go to our website. I'm too lazy to sort it out and post it here

[Stephanie]

just a thot, but i don't think photoquality is going to be the main problem.

could a flash from a camera screw up a robot's sensors (is anyone even using sensors?) ? if the light reflects off of the tape during a match, could it trip up the robot?

oh, duh, no it wouldn't, because it would still tell the bot where the goal is. Okay, disregard this post

[Greg Ross]

Originally posted by Stephanie
oh, duh, no it wouldn't, because it would still tell the bot where the goal is. Okay, disregard this post

Not only that, but remember they're RETRO-reflectors. The light from the flash (at least a high percentage) gets reflected directly back at the source!

Also, the sensors only detect a narrow range of infrared light. I don't know how much of that wavelength is emitted by the flashes.