Protective filter for BTX objective lens (2 Viewers)

[andrea86bert]

Hi,
I want to protect the lens from salt and sand.
On Swarovski website i have read M87 x 0,75 and I suppose that I have to self-build the filter.
Do you have any experiences with filter for BTX/ATX objective lens?

Thanks,

Andrea

 

[forent]

https://www.birdforum.net/showpost.php?p=3949123&postcount=3

 

[andrea86bert]

Thank you very much forent!