Clear the view through the wood

1 · Turn the filter

Beginner

The logo behind the sheet is blurred. Which way do you turn the polarizing filter to sharpen it?

Along the fibres Across the fibres Any way at all

2 · Change the colour

The filter stays across the fibres. Now for the spectrum lamp, tunable from violet (400 nm) to red (800 nm).

Intermediate

Across the fibres, haze follows H = 0.08 + C/⁠λ² and is 21% at 800 nm. What is it at 400 nm?

About 60% About 84% About 34%

3 · Read the slope

Expert

Across the fibres, from 800 to 400 nm, the colour-dependent part of the haze is multiplied by 4. What does that tell you about what deflects the light?

Finite-size specks, weakly contrasting Specks vanishingly small next to the wavelength Thin air gaps between plastic and wall

4 · Aim for wooden glass

Expert

Practical wooden glass needs at least ten times less haze than the best published results, around 50%. Across the fibres, can the law H = 0.08 + C/⁠λ² get there?

Yes, by going far enough towards red No, never below its constant term No, but it gets close near 800 nm

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