Mixing unmounted and mounted filters in wheel

[morls (Stephen)]

Hello everyone,

I've got a set of Baader LRGB filters in 31mm unmounted format. I also have a Baader H-alpha 31mm unmounted. I haven't been able to find the Baader O-III or S-II in the unmounted format, only mounted. I don't think they produce 31mm unmounted versions

In light of this, I've bought an Optolong O-III 31mm unmounted, but am still undecided whether to go for a Baader SII 1.25" or look for a 31mm unmounted version.

Would there be any issues with using a mix of mounted and unmounted filters in my wheel? I have a ZWO 8-position EFW, which takes both formats.

Cheers
Stephen

[morls (Stephen)]

I might not have been clear...
What I'm wondering is whether this would cause any issues with focus? Does the filter surface sit further back in the imaging path with mounted filters vs unmounted?

[Don Pensack]

Originally Posted by morls

I might not have been clear...
What I'm wondering is whether this would cause any issues with focus? Does the filter surface sit further back in the imaging path with mounted filters vs unmounted?

Yes, and they won't be parfocal.