OAG setup with 585mm lens requires 10mm spacer for proper focus

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Florian Wi avatar

Hey there!

I wanted to try out an OAG with my 585mm and the SV555. Yes I know no need for OAG with this focal length but since I have to carry everything up a ladder to the roof I figured smaller would help

My problem now is that I had to put a spacer between the EFW and the 585 to achieve focus with the OAG and the guide cam

10mm

Now the 585 isn’t screwed into the OAG anymore and has more distance to the filters

Thanks

Florian

Quinn Groessl avatar

https://i.zwoastro.com/wp-content/uploads/2025/03/7545e060197bb1b1d0fe98a18d9a540a.jpg

I don’t really see a question, but the link above is ZWO’s diagram for getting 55mm of spacing with an EFW.

Florian Wi avatar

True there is no question 🤣

The question is will there be a problem if I leave it like that?

This is the only way to get focus on the oag

I know the ZWO diagrams

Cheers

Quinn Groessl avatar

It depends. The further away your filters are from your sensor the more chance there will be vignetting, but with the small sensor of the 585 that might not be an issue. Otherwise if everything else works it’s fine.