Need to use 3 extension rings to reach focus -normal?

[Cliff]

Hi,

This is my situation, I have a Explore Scientific 80ED . My second scope and first refractor .

When using the ZWO 178MC camera with this scope without the diagonal as was suggested to be better I need the two 2" Extensions supplied and an additional one which I am using part of the Bintel Projection adapter to reach focus. If I add a Barlow can't even get focus would need another ring.

I see others setups and this seems a little unusual to have it hanging so far back. Is this a characteristic of this scope ?

Appreciate any ideas,
Cliff

[Merlin66]

Cliff,
Not unusual. You have to compensate for the diagonal, this can require added spacers.

[Wilso]

Hi Cliff,

It depends on the Barlow your using, they do vary a bit.
My Takahashi 2x 2 element Barlow requires inward focuser travel and my parks gold 2x 3element Barlow is pretty much parfocal with the eyepiece.
If you have run out of focuser travel try sliding out the Barlow or eyepiece a little with 1 or 2 extensions to see if it reaches focus.

Good luck :thumbsup:

[Cliff]

The Barlow is just the cheap one supplied in the Meade Eyepiece Case. Don't have another to try it, An Eyepiece alone reaches focus ok.

Cheers,
Cliff

[Cliff]

Thanks Ken,

Pretty new to all this so learning lots. I figured I needed more spaces without the diagonal just not so much.

Cheers
Cliff

[Ukastronomer]

Believe me when I first started two years back, with "new" gear I wondered the same thing it is normal

[Cliff]

Thanks Jeremy,

I guess it seems strange as I can easily get focus without any tubes on my Meade 6" SCT. May need to find another proper extension tube that fits instead of using the Bintel Projection adapter.

Didn't seem to work for me anyway the projection unit is supposed to allow an eyepiece and camera to give higher magnification. Pretty poor results ?

Cliff