Diffuser/Opal Glass in Australia?

[Poita]

I need a 50mm diameter opal glass or similar diffuser to give a near lambertian diffusion from a LED COB.

I have found them at Knight Optical and Edmund Optics, but the postage is around $100 or more.

Does anyone know where to source such a thing locally in Oz?

[DavidU]

Just get a 50mm camera lens filter, remove the glass and then wet sand it with #800 wet and dry sandpaper, works a treat and would be very cheap.

[Hemi]

Pardon the ignorance, can I ask what you use a lambertian diffuser for? Im guessing for flats but am a relative newbie so no laughing.

Cheers

Hemi

[Poita]

To be honest, it isn't for Astronomy, but I thought I'd ask in here as there are so many optics gurus.

[JohnF]

I have a German Lietz microscope ground glass projection screen in holder for sale. It has ground opal glass in it, but is about 8 inches in diameter.

I live 12km north of Nimbin in NNSW.

It will be cheap -- make me an offer. Would swap for some telescope Eyepieces.

This is not it, but similar to give you an idea of what I mean. Microscope is not included.

http://www.radicalmicroscope.com/student-projection-microscope-1224566.html

[Exfso]

I use Opal perspex for my light box diffusers, dont suppose that helps much if you specifically want glass.