Yes, thanks for pointing that out. It also mentions being optimized for visual in terms of color correction. And as a comparison I believe you mentioned your GTX is corrected for 400 - 706, and your 16200 chip does not show the halos with that scope. I'd love to hear from someone on whether or not the published color correction wavelengths could be tied somehow to these halos and/or UV light transmission. I'm way out of my element when we start going down that road.
I don't believe it is the scope at all. Microlens diffraction occurs within the sensor itself, only. The microlens array diffracts, that diffracted light bounces off the back of the sensor cover glass and back down to the sensor. The scope is not involved in that at all. Even if a scope is not well-corrected at UV wavelengths, they can still pass them. That is all that the scope needs to do here...pass UV wavelengths down to 360nm.
I believe the issue is simply that the IMX183 AR coating on the cover glass is simply not canceling out UV wavelengths. AR coating has to target specific wavelengths of light to cancel out. It is a multi-layer coating (anywhere from 2 to hundreds, depending on how advanced it is). The more layers, the more distinct wavelengths of light can be targeted to be canceled out. It is rather doubtful that UV rays from 399 down to 360 are going to be covered by the AR coating on the sensor. I would actually be surprised if it had more than just a few layers, and was targeting wavelengths around "red", "green" and "blue" only, thus being an imperfect cancellation of even the visible spectrum.
Since your filters are allowing UV light as deep as 360nm to pass...if the AR coating is indeed NOT canceling those wavelengths, then any microlens diffraction will shine brightly at those wavelengths.
Edited by Jon Rista, 17 March 2019 - 01:18 AM.