Looking for a supplier for a customized glass filter:
material: glass (no plastics) sorted float glass might be OK
aprox size: 20x14 inches, 3mm thick
coatings: face1: AR, Magnesium Fluoride as the more likely candidate face2: ND, 60% transmission (aprox).
wavelength: visible range
s/d: 60/40
The ND portion could be done with ND glass, such as Schott S4020 (which doesn't come in large enough sizes).
The size seems to be the main stubling block. I'm finding out that a great deal of optics companies can't work with pieces that large.
Most companies I've contacted in the US seem to prefer to do high-dollar government-military work. I've been quoted $1K to $3K for this filter, which I think is entirely too much.
Any leads would be appreciated,