Dobsonian and EQ platform test tonight (M45)

[fwm891]

Lots of issues mainly sensor plane tilt. Attached image is 20x 5 sec subs, 800 iso using a Nikon D5100 mono mod camera (DX/APS-C sensor). Processed in PI only.

Comments welcome.

First time I've been out with almost completely clear skies yet it was raining 🌧️ !

 

[RobertI]

Impressive result for short total exposure time.  

[Alan White]

Clear and raining, I thought that only happened to me, clearly it’s a shared experience.

Is this with the 12”?

[fwm891]

On 10/12/2022 at 08:38, Alan White said:

Clear and raining, I thought that only happened to me, clearly it’s a shared experience.

Is this with the 12”?

@Alan White Yes the 12 inch VX12. Tried again on NGC891 still not nailed the PA on the EQ platform. Great for visual but still off for photog.

 

[DSviewer]

Looks great

[bosun21]

Great work 👍 I’m waiting for David Lukehurst to finish my EQ platform for my new 12” dobsonian. It should be sometime in February. I am now going to put some thought into the how I can PA align accurate enough to take photos. Thanks you have given me some inspiration.

[fwm891]

4 hours ago, bosun21 said:

Great work 👍 I’m waiting for David Lukehurst to finish my EQ platform for my new 12” dobsonian. It should be sometime in February. I am now going to put some thought into the how I can PA align accurate enough to take photos. Thanks you have given me some inspiration.

Not sure how David is building his EQ platforms. I've made my south end pivot on a big ball bearing the rear edge of its support I've cut to my latitude angle (52°N) and glued a side piece/fence to act as a shoulder. I have a low power green laser that I tape against the shoulder piece/fence. I do a rough ish eyeball to get my baseboard pointing North, then I level east/west and finally north/south with a bubble level. Then I switch on the laser and make finer adjustments until I get the laser pointing at my guess to the rotational pole. There may be some iterations to the levelling depending on the ground level I'm working off.

A previous version held a raci finder in a little cradle but I can't get down that low these days to look through it. The laser's much easier to see without breaking your neck! Make sure you can't see any aircraft when using the laser.

Francis

 

Edited January 29, 2023 by fwm891

[bosun21]

6 hours ago, fwm891 said:

Not sure how David is building his EQ platforms. I've made my south end pivot on a big ball bearing the rear edge of its support I've cut to my latitude angle (52°N) and glued a side piece/fence to act as a shoulder. I have a low power green laser that I tape against the shoulder piece/fence. I do a rough ish eyeball to get my baseboard pointing North, then I level east/west and finally north/south with a bubble level. Then I switch on the laser and make finer adjustments until I get the laser pointing at my guess to the rotational pole. There may be some iterations to the levelling depending on the ground level I'm working off.

A previous version held a raci finder in a little cradle but I can't get down that low these days to look through it. The laser's much easier to see without breaking your neck! Make sure you can't see any aircraft when using the laser.

Francis

 

I have no idea how he’s making them, or to what design. I trust his woodworking and mechanical skills as he has sold about 50 of them and there’s been no complaints. I have already bought my 1 meter spirt level. Which camera are you using with your dobsonian? And are you using a coma corrector? Thanks 

[fwm891]

10 hours ago, bosun21 said:

I have no idea how he’s making them, or to what design. I trust his woodworking and mechanical skills as he has sold about 50 of them and there’s been no complaints. I have already bought my 1 meter spirt level. Which camera are you using with your dobsonian? And are you using a coma corrector? Thanks 

I've been using a Nikon D5100 with a Baader MPCC Mk 3 coma corrector mainly becuse it's a light weight (physical) body and I have a intervalometer with it to take a number of or single frames. I've yet to try with a astro camera. The small chips on mine I'm guessing will make object location a pain. At least ther nikon is DX/APS-C format so finding things isn't too bad.