Is optical reflection loss through multiple objects added or compounded? I am taking a solar cell class and came across a question that deals with reflection losses as light passes through multiple materials before it reaches the solar cell. I tried to look up optical properties and laws, but can't seem to find the one that deals with this. This isn't the problem I'm working on, but an example. A solar panel is in a glass case. The glass case reflects 8% of the light. The silicon is reflecting 38% of the light. Is it 100% - 8% - 38% for a total of 54% of the light being transmitted into the cell, or 100% - 8% = 92% - 38% = 57.04% of the light being transmitted into the cell? This is really confusing me.

The process can't be subtractive. Imagine you had three layes with the same reflectance as silicon. A subtractive formula would give

$$100\%-38\%-38\%-38\%=-14\%,$$ which is meaningless.

The process is multiplicative. After the first reflection, what remains passes the next diopters and undergoes other reductions in the same proportion,

$$100\%\to62\%\to62\%\cdot62\%\to62\%\cdot62\%\cdot62\%=23.8\%.$$

Hence

$$(100\%-8\%)\cdot(100\%-38\%)=57.0\%.$$