My Bahtinov mask has 8 spikes instead of 6

[cuivenion]

As in the title, has anyone any idea what I could be doing wrong?

 

[tooth_dr]

Thanks gonna make it tricky! Have you a photo of your mask? New phenomenon and previously working ok?

[cuivenion]

8 minutes ago, tooth_dr said:

Thanks gonna make it tricky! Have you a photo of your mask? New phenomenon and previously working ok?

Used twice many months apart. Thought I must have done something wrong the the first time  so I gave it another go. Same result both times. I was using it with a 130pds Newtonian.

[tooth_dr]

It doesnt look quite right that mask, well it's not the same as mine.  There should be parallel lines in one half, yours are slanted in both sides.

 

[cuivenion]

It look different, definitely. Looks like I have a duffer then.

[cuivenion]

From looking on the net it looks like it might be a Y mask. Still should have 6 spikes though.

[LeoLion]

I believe that what you have is a Carey Mask  http://www.geoastro.co.uk/careymask.htm . Should work on the basis of the comments in the link including the comments on the diffraction spikes you get with that mask pattern. Hope this info helps.

[cuivenion]

Thanks, that seems to be it. Very annoying, it was sold to me as a bahtinov mask.