[Zuts]

Hi,

I have a TV85 with a FL of 600mm. I use a 0.8 reducer which gives me a 480mm FL.


Bearing in mind ZWO cameras require a 55 mm backfocus I have spacers screwed into the camera so that there is 55 mm between the top of the reducer to the chip.

When I measure with a tape there is 480 mm from the front lens of the scope to the lens of the reducer when everything is in focus.

You have an ED80 which has the same FL, but a 0.85 reducer. So I would do roughly the same to get a rough focus, i.e camera with 55 mm of spacing to the chip, then reducer, then roughly 510mm to front of telescope lens and you should see stars when you take a photo. Then you need to fine focus from there.