Chroma Filters Orientation?

[STEVE333]

Hi All - I have just purchased Chroma Ha and Sii 3nm filters.

Does it matter which side faces the camera?

If the answer is yes, how do I know how to orient the filter?

Steve

[mbocca]

Steve,

I don't know if this applies to Chroma, but this is what I used for the ZWO filters that I use.

https://www.cloudynights.com/topic/6099 ... ientation/

Mike

[STEVE333]

Steve,

I don't know if this applies to Chroma, but this is what I used for the ZWO filters that I use.

https://www.cloudynights.com/topic/6099 ... ientation/

Mike

Thanks Mike - I contacted Chroma and their expert said that they no longer recommend a preferred orientation. Some users find one orientation works best for them and and some find the other orientation works best. Grrrrrrrrrr. Not the answer I wanted to hear!! They asked me if I would let them know which orientation works best. Sigh.........

It is quite a bit of work to dismantle my setup to get to the open filter wheel, and, I hope I guess right for the two filters.

Steve

[JayTee]

I'm sorry Steve for the lack of direction from the manufacturer -- it just shows to go ya, that if it's not one thing, it's another!

Cheers,
JT

[ram]

Hi Steve, I'm not entirely surprised Chroma said what they did but also to answer your first question, yes, it typically does matter. The thread that Mike pointed you to I think tells you how to check for the anti-reflective coating side. I use this guide:

https://www.peterzelinka.com/blog/2020/ ... otography-
filters#:~:text=The%20mounted%20filters%2C%20with%20threads,ll%20always%20install%20them%20correctly.

https://www.cloudynights.com/topic/5911 ... rect-side/

"One of the hardest parts of the installation was determining which side had the anti-reflective coating. One side of the filters has an anti-reflective coating, which should be facing the camera sensor. Unfortunately, I could not tell the difference. Therefore, I probably installed a few filters upside down. "

But others in CN have posted you can reverse it and get better data. So "try it out and see" seems like a fair answer but IMO that advice, the anti-reflecting coating side should be facing camera sensor I think is what you can try first...

--Ram

[yobbo89]

I believe chroma filters aren't double anti reflection coated, so it does matter, yet I had news they work either way but if you're getting some internal reflection then you'll want to have them the correct way. I think only astrodon double coat their filters.

[STEVE333]

Thanks for responding guys. I already have a Chroma 3nm Oiii filter in the filter wheel. It is working well, so, I'll put the Sii and Ha filters in with the same orientation and hope for the best. I'll try to remember to report how things work out.

The filters just arrived this afternoon. I'll probably put them in tomorrow and then generate some new Flats. The skies are expected to be clouded (or fogged) over for at least tonight and tomorrow night, so, no hurry. However, with the new flats I will be ready when the clouds/smoke do finally clear.

Cheers,
Steve