My team was wondering if there were any alternatives for the 3M reflective tape. And does 3M reflective tape have any different qualities compared to other brands that would affect our vision targeting?
I don’t see any reason why this would be sufficiently different than the 3M tape to matter:
My understanding is that the primary characteristic of the 3M tape is that it is specifically retroreflective— that is, it reflects light only in the direction of the origin of that light. Presuming you can find an alternative retroreflective tape to use, I would concur that it likely isn’t terribly different.
I just went to Home Depot and bought some, and put it side-by-side with some 3M retroreflective tape I got from AndyMark in (IIRC) summer 2016. It is slightly whiter in color in room lighting than the 3M, but definitely retroreflective under green LEDs, though slightly less so than the 3M tape. If you get your code working with the HD tape, you should be in really good shape for the field tape.
In both cases below, the top strip of tape is the 3M, the lower is from Home Depot.
If there are significant differences, every event I’ve been to has an hour on Wednesday to let teams on the field to calibrate their vision tracking. You could always get “close enough” with the cheap tape and then readjust when you get to competition.
Any retroreflective tape will be fine. If you are wondering about a tape, take a picture of it (from any angle) with a camera (your phone) with the flash on. If the tape shows up bright white, it is going to work.
We were able to buy the 3M tape easily from Identi-Tape:
I wouldn’t go quite that far. There are two main types of retroreflective tape, prismatic and glass bead. The two have somewhat different behaviors, meaning you’re probably substantially better off testing with a glass bead tape (that’s what the 3M tape is).
The Home Depot tape referenced above looks like glass bead, prismatic usually looks much shinier with a visible crosshatching pattern on it.
If you test with an alternative like the Home Depot tape, understand what parameters you would need to tune if the reflection gets dimmer or brighter when you calibrate at the event, and have a procedure for how to do that, you should be in good shape.
The Home Depot tape is also “glass bead” variety. Using a loupe, it looks to have about half the density of glass beads as the 3M, and a wider variation in bead sizes. While the 3M has a rough surface (like an over-used piece of 220+ grit sandpaper or starched woven fabric) which makes me think that the glass beads are sprinkled onto an adhesive, the HD tape has a smooth glossy surface, as though it has a layer of packing tape on top of the glass beads. As I said before, the 3M tape is definitely more retroreflective, so if you can get your system working with the HD tape, you should be able to adapt to the 3M tape much better than the reverse, especially given that the actual field will have a more reflective surface adjacent to the RR tape (polycarbonate) than most team fields (plywood).
Our team has used the silver parts of this Safety Reflective tape: https://www.amazon.com/X4yard-Waterproof-self-adhesive-tape-reflective-Conspicuity-reflectante/dp/B01MU2LLIF/ before we got some of the official 3M tape. We’re testing with a limelight and both the silver safety tape and the official 3M tape look identical to our camera. At least with the limelight settings we are using.
That’s prismatic tape. In general it is likely to be brighter (though this particular material may not be) on-axis and dimmer off-axis than glass bead tape.
Can someone direct me to where reflective tape is on the field I seem to be overlooking the area on the manual
Section 3.7, Vision Targets.