A question about filters

[pmrid (Peter)]

I have just loaded up a new FW with an old set of 7 Baaders I’ve had for some time but not used. The NBs are not the new ultra-narrow ones but are 7, 8 and 8.5 nm bandpass. I notice however that the packaging boasts “no halos, no reflections”. But I also notice - most apparent on the NBs - that one side has a very reflective surface and the other does not.

It seems a silly question to be asking but is there a particular orientation for these filters - reflections outwards or towards the ccd?

[JoelRed (Joel)]

Originally Posted by pmrid

I have just loaded up a new FW with an old set of 7 Baaders I’ve had for some time but not used. The NBs are not the new ultra-narrow ones but are 7, 8 and 8.5 nm bandpass. I notice however that the packaging boasts “no halos, no reflections”. But I also notice - most apparent on the NBs - that one side has a very reflective surface and the other does not.

It seems a silly question to be asking but is there a particular orientation for these filters - reflections outwards or towards the ccd?

Hey, usually you put coated surface away from the camera.

Antlia has an explanation of how to mount their filters, I would assume it would be similar for Baaders.

http://www.antliafilter.com/nd.jsp?id=20

Hope it helps!

[pmrid (Peter)]

Thanks Joel. It does help. I had the filters right about 4 to 3.
That double shadow trick is a good test.

P.