Flip mirror - how to match focus of eyepiece with camera?

[Splittersplatter]

Hi, does anyone here use a flip mirror? It's a fantastic tool but for the life of me I can't match focus. I've tried extending the camera out, and lifting the eyepiece out of the tube, but it seems the only thing that would work is making the camera recede into the box somehow which obviously you can't do. Clearly I'm being stupid, but how?

[MattJenko]

I thought the idea of these was to help get the target in the center for the camera, not to get it in the center AND in focus.

[PeterCPC]

You could try moving the EP out a bit or a different EP. It doesn't have to be in accurate focus as Matt says.

Peter

[Splittersplatter]

2 hours ago, MattJenko said:

I thought the idea of these was to help get the target in the center for the camera, not to get it in the center AND in focus.

It makes life a lot easier if eyepiece and camera are in focus at the same time. 

[Alien 13]

The light path through the diagonal mirror will be longer by about 50mm so you might need spacers in the straight output to get the camera in focus.

Alan

[michael8554]

Hi Splittersplatter

What brand of flip mirror do you have? The best ones have adjustable path lengths.

This is an adjustment best carried out during the day on a distant terrestrial object.

If your flip mirror doesn't have adjustable path lengths:

Focus with the camera in the straight-through path.

Pop the eyepiece fully into the other port but don't fully tighten.

Then slowly draw the eyepiece out of the port until you have focus. 

Then fix a parfocal ring on the eyepiece so that it always inserts to that depth.

If the eyepiece won't get to focus because peversely it wants to go further into the port, then tighten it in the fully inserted position, but this time  focus the scope for the eyepiece instead of the camera.

Then carefully slide the camera out of its port until it's in focus too.

If the camera nosepiece is long enough to safely fit the parfocal ring on it, fine, if not  fit a spacer of the right length into the camera adapter.

Michael