The underlying issue is that the lens accepts a cone of light from every point on the subject. That means it is seeing light that travels through the glass at different angles. When the glass is slanted with respect to the optical axis, the light on the "high" side of the cone spends more time inside the glass than the light on the "low" side of the cone.kaleun96 wrote: ↑Wed Jan 04, 2023 2:39 pmin my case with the slanted glass the light would be travelling through the same amount of glass regardless of where it hits along its surface - assuming the light is hitting it a 45 degree angle relative to the surface.
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I'm likely missing something obvious as I have a long way to go before being able to keep up with many members here when it comes to the behaviour of light and optics.
Here is a diagram to illustrate. This is a ridiculously wide aperture compared to what you'll be using, but hopefully it gets the point across. Compare the lengths of the bold lines. They represent the amount of glass to be traversed by light on the "high" and "low" sides of the cone. It's that difference in time inside the glass that causes the aberration.
--Rik