Olll filter stopping filter wheel to close.

[Taff]

Hi' For the first time today i placed a CLS' filter, a light pollution filter, into the filter wheel they fitted fine.But when i placed the Olll filter into the filter wheel the back of the filter wheel would not close to screw together.The only way the filter wheel would close is when i placed the Olll filter up side down in the hole.What i like to know can i still use the Olll filter when it is the wrong way up in the filter wheel Thanks for looking.Mark

[Jannis]

From what I've understood the filtering effect itself remains when flipped, but it could cause issues with internal reflections.

Sounds odd that it only fit upside down though, i thought most wheels were designed so they would be at it's lowest when facing the correct way? May i ask what filter and wheel is this?

[Taff]

Hi Jannis' It is called a Skywatcher 5 position filter wheel.Mark

[Adam J]

Unfortunately in so far as I know while broad band filters are generally non directional so the CLS or a UHC, Narrow band filters are not and must be placed in the correct direction to function correctly.

[Taff]

Hi Adam' Thanks for the information on the filters'.Mark