SII filter reflections

dansemacabre

I recently obtained a brand new ASI1600 set with EFW and 36mm unmounted LRGB+narrowband filters. All filters works perfectly and more or less parfocal, except the SII which makes a terrible reflections on all stars with magnitude 7 and less. I tried to unscrew EFW and place the filter upside down, but there's no change.

Do anyone else have this experience?

Sam@ZWO

you can try to reverse the order you connect the EFW

dansemacabre

There's no change. Filter orientation apparently doesn't matter. Here are my results with OIII and SII filters - terrible reflection on 7,5mag stars, which is not acceptable for me :( Is it normal or there's a possibility that filters are possibly defect somehow?

Sam@ZWO

actually, it's not very bad from our point of view

if change order won't fix, then there is no way

this reflection is optics related too

dansemacabre

There is no such problem with Ha or LGRB filters. And there is no such problem with other same priced filters from different company (which also causes reflection, but for stars 1,5mag brighter, not for 7,5mag!). Can it be just possible I had a bad luck about this particular pieces?