[HiroshiSan]

Why don't you like that explanation? Leonardo was obsessed with detail, and he would study things intensely, it's not that much of a stretch.

[anoncake]

Which is why you'd expect an orb painted by Leonardo to have the correct optics.

[HiroshiSan]

Wasn't the orb supposed to symbolize Jesus performing another miracle by not having the light warp the fabric?

[wl]

That's exactly the argument I'm dismissing. It's not much of a miracle for the orb to transmit light as one would naïvely expect. Rather, it suggests that somebody didn't do their homework.