Guiding focus

[Hoopla]

Hi,

 

I recently purchased the below from FLO and am really struggling to get good focus on my guide camera and wondering if you can give me any suggestions. It’s consistently losing the star whilst guiding. 

 

I have tried extending the front by unscrewing etc but to get any sort of focus I need to have the red screw piece practically all the way in and the camera on the very extreme outer edge to get any level of stars in view. I just can’t seem to get a decent enough focus so am hoping you can offer some advice / guidance please?

I’m using an ASI AIRPRO for the guiding. 

Edited March 28, 2021 by Hoopla
Wrong wording

[knobby]

Can you try in the day time on a distant object ? Lots of people use this setup so I'm sure it will work 🤞🏻

[Jonny_H]

To get focus with my 120mm mini and 50ed guide scope set-up I have to have my guide camera sticking out of the end of the guide scope a fair bit more than I expected. Have you tried sliding the camera further back and/or screwing on the supplied spacer to the camera etc....?

Alternatively I would suggest focusing on a distant object in the daytime as suggested by knobby. You can then fine tune later in the night.

[Adreneline]

Not that is any consolation or help but I have experienced the same difficulties with the mini guide scope.

I added a 1.25" nose piece extensions to the camera which allowed me to increase the back focus, however, even with a mechanically  "secure" camera I still really struggle to achieve a good level of focus compared with my SW Evo Guide. The FWHM with the mini guide scope is consistently above 4 compared with the Evo Guide which typically achieves better than 3.

It is worth noting that I need to use the same nose piece extension when using the camera with the Evo Guide. Fitting a spare 1.25" UV/IR filter to the camera seemed to help as well.

Adrian

 

[teoria_del_big_bang]

I don't have that guidescope but I do have a zwo mini ccd for the guidescope and also had to pull the camera back a long way in the guidescope to achieve focus.

I would put the focus adjustment on the guidescope back to somewhere about midway so you have fine adjustment both ways.
Then in daytime try to focus on a distant object (something on a distant hill or whatever you can). Then pull camera back by hand  whilst monitoring in real time in some program like ASICap and fiddle with this distance till you get best focus.
You then have the adjustment on the guidescope to get good focus.

To focus on stars the exact focus will be a bit different to the object on earth you focussed on but you will then have a good starting point so should not take too long in the night.
So you can do the same things as this in the night, you can even focus on the moon first if you want and then focus on stars will be not too much different from that and in fact pin point focus not necessary for good guiding but needs t be somewhere close.

Then all that's left is to mark the position of where the mini ccd sits in the clamp in case it is removed. I have 3D printed spacers before but a bit of tape r a black marker pen works well as well.

Steve

Edited March 28, 2021 by teoria_del_big_bang

[Chefgage]

On 28/03/2021 at 07:46, Hoopla said:

Hi,

 

I recently purchased the below from FLO and am really struggling to get good focus on my guide camera and wondering if you can give me any suggestions. It’s consistently losing the star whilst guiding. 

 

I have tried extending the front by unscrewing etc but to get any sort of focus I need to have the red screw piece practically all the way in and the camera on the very extreme outer edge to get any level of stars in view. I just can’t seem to get a decent enough focus so am hoping you can offer some advice / guidance please?

I’m using an ASI AIRPRO for the guiding. 

Take a look at this video. At the 5 minute mark he shows the measurements at which the camera and focuser should be set at. I did this and then I could see stars. A bit of fine tuning and I am nicely focused.

https://youtu.be/2oiTVGA2zIs

[Hoopla]

8 hours ago, Chefgage said:

Take a look at this video. At the 5 minute mark he shows the measurements at which the camera and focuser should be set at. I did this and then I could see stars. A bit of fine tuning and I am nicely focused.

https://youtu.be/2oiTVGA2zIs

Thanks for the comment and I’ve now set mine to the same or near enough values. However the kit seems to be slightly different from what I have so will have to see later tonight.