Can someone explain this please….🤔

[Stuart1971]

So can someone please explain why these unmounted filters are fitted to filter wheels differently for Narrowband and LRGB, surely the anti reflective surface should be the same way round for all filters….it really confuses me, that there fitted the opposite to each other…..

this is from the internet and think it’s from ZWO

 

Edited December 14, 2023 by Stuart1971

[tomato]

I must admit I have always put mounted filters LRGB and NB, onto the same side of the filter wheel carousel, but then the manufacturer could put the filter into the mounting ring the correct way round to enable this.

I await further posts with interest.

[teoria_del_big_bang]

I have never seen instructions like that. Like you say it seems wrong.
I have always used the little arrow on side to orientate them. 
Only other thing I have read, on the Badder website is that if you suffer halos to try them opposite way round and on my Baader OIII I had terrible halos bit the same which ever way round I fitted it.

Steve

[Stuart1971]

1 hour ago, tomato said:

I must admit I have always put mounted filters LRGB and NB, onto the same side of the filter wheel carousel, but then the manufacturer could put the filter into the mounting ring the correct way round to enable this.

I await further posts with interest.

Yes, this is more about unmounted 36mm or other size unmounted filters, the ones in cells, I have always screwed in the same way, as they would never go in any other way…🤔

[Stuart1971]

1 hour ago, teoria_del_big_bang said:

I have never seen instructions like that. Like you say it seems wrong.
I have always used the little arrow on side to orientate them. 
Only other thing I have read, on the Badder website is that if you suffer halos to try them opposite way round and on my Baader OIII I had terrible halos bit the same which ever way round I fitted it.

Steve

No little arrows on the side of any of my 36mm unmounted filters, unfortunately ☹️

[tomato]

3 hours ago, Stuart1971 said:

Yes, this is more about unmounted 36mm or other size unmounted filters, the ones in cells, I have always screwed in the same way, as they would never go in any other way…🤔

Agreed, after I posted I thought about it and realised you can only put them in one way, I don’t think there is sufficient clearance with the FW housing to put them in on the other side of the carousel, even if you wanted to.

Beats me why NB filters would be treated different to LRGB.

[ollypenrice]

4 hours ago, teoria_del_big_bang said:

on my Baader OIII I had terrible halos bit the same which ever way round I fitted it.

Steve

So did mine!! And so did my Astronomik. And so did the Astronomik which they sent me as a replacement for the first one!!!

lly

[Tomatobro]

is it that some have a AR coating and some do not? 

[ollypenrice]

My understanding is that interferomtric filters work by creating a succession of reflective layers spaced so that only a certain wavelength fits between all these layers and so makes it to the exit.

If this is correct (not guaranteed!) then I don't think there is any reason to assume that the first (outer) layer should be reflective. It might be reflective on one filter and not on another...

Thinking out loud so don't shoot me.

Olly

[Stuart1971]

2 hours ago, Tomatobro said:

is it that some have a AR coating and some do not? 

Well according to the above image I posted, both the LRGB and Narrowband have the anti reflective coating, this is why I am confused, my thoughts would be that the Anti reflective coating should always point towards the scope….but this is not the case….depending on the filters used….🤔🤔