4 ms·
The rather shallow angle probably helps a lot. On top of that the camera probably has some form of auto white balance which will counteract the tint the CD will
by simias 6y ago
The rather shallow angle probably helps a lot. On top of that the camera probably has some form of auto white balance which will counteract the tint the CD will give to the image.
Here's a quick proof of concept using a random CD and my phone's camera: https://svkt.org/~simias/up/20200914-000627_psx-cd-reflection.jpeg https://svkt.org/~simias/up/20200914-000627_psx-cd-reflectio...
Note that the color of the reflection is not much different from a normal picture (visible at the bottom). For added difficulty I used an original PlayStation disc, that's dyed black: https://svkt.org/~simias/up/20200914-000836_psx-cd.jpeg https://svkt.org/~simias/up/20200914-000836_psx-cd.jpeg
- jeffbee 6y agoIt's very HN that we've been trolled into debating the irrefutable, widely-known, totally obvious fact that a CD reflects light.
- Xavdidtheshadow 6y agoEverything reflects light, but not everything reflects it clear enough to read documents through. I haven't held a CD in ages, so it it's possible that folks don't remember exactly how reflective they are. ¯\_(ツ)_/¯
- bentpins 6y agoDidn't mean to come across as a troll, this is how I remember CDs, with rainbow diffraction. https://www.google.com/search?tbm=isch&q=cd https://www.google.com/search?tbm=isch&q=cd
- simias 6y agoI think at such shallow angles it's the plastic surface that becomes reflective, not the metal layer with the pits and grooves. Hence the lack of diffraction (and hence why it works with my black PSX disc).
- kevin_thibedeau 6y agoShe's using a CD-RW with blue/purple dye. The reflection is definitely coming off the surface.
- Someone 6y agoAlmost everything reflects light. The discussion is on why it can be used as a mirror.
- gibolt 6y agoThe quarter helping to hold down the CD may also contribute by blocking overhead inbound interference.