Focusing the ZWO mini guide scope

[Cornelius Varley]

3 minutes ago, amartinwest said:

I am having problems focusing this device, wish I read this before buying 😞

The focal point seems to about 30 cm behind where it should be. I took this picture ...

 

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Please upload photos in either .jpg or .png format so that they can be viewed within the browser.

[AstroMuni]

1 hour ago, amartinwest said:

I am having problems focusing this device, wish I read this before buying 😞

The focal point seems to about 30 cm behind where it should be. I took this picture ...

What is the spec of this? Presuming we are seeing the rear end of a guidescope?

[amartinwest]

1 hour ago, Cornelius Varley said:

Please upload photos in either .jpg or .png format so that they can be viewed within the browser.

I did replace it but must have omitted to save the edit, sorry.

[amartinwest]

Its the ZWO 30F4 - supposedly 120mm focal length.

[amartinwest]

6 minutes ago, amartinwest said:

I did replace it but must have omitted to save the edit, sorry.

Actually it is replaced, you must have picked it up before I was able to replace ir.

[amartinwest]

1 hour ago, AstroMuni said:

What is the spec of this? Presuming we are seeing the rear end of a guidescope?

So just as an experiment I put a celestron T barlow on the back of the scope and the camera onto that and I can now focus on a distant object, oh my brain hurts

[StevieDvd]

1 hour ago, amartinwest said:

So just as an experiment I put a celestron T barlow on the back of the scope and the camera onto that and I can now focus on a distant object, oh my brain hurts

You focus this finderscope by loosening the red locking ring which then lets you screw/unscrew the front to change the focus.

Look at the last image on the ZWO page here.

HTH

Steve

[AstroMuni]

2 hours ago, amartinwest said:

Its the ZWO 30F4 - supposedly 120mm focal length.

If its anything like my Astro Essentials one you need to unscrew a lot before you achieve focus. 12cm is measured from the rear surface of the lens system in the front, so can be a bit tricky to figure out true distance.

[amartinwest]

34 minutes ago, StevieDvd said:

You focus this finderscope by loosening the red locking ring which then lets you screw/unscrew the front to change the focus.

Look at the last image on the ZWO page here.

HTH

Steve

Yes, have tried that but its probably not clear from my photo but the focal point is about 30cm back from the end of the scope. It works with T barlow and I can focus it as you state. I can only suppose that it has the wrong lens. I bought it some time ago but have only just got around to using it. Thanks

[StevieDvd]

1 hour ago, amartinwest said:

Yes, have tried that but its probably not clear from my photo but the focal point is about 30cm back from the end of the scope. It works with T barlow and I can focus it as you state. I can only suppose that it has the wrong lens. I bought it some time ago but have only just got around to using it. Thanks

It is tricky to focus, needed to be screwed almost until it comes off at the front and has a ZWO camera with the longest 1.25" nose piece to get some focus in my case. I used a parfocal ring to save the depth the camera is focused in.