All Sky Camera Revisited

[Gina]

Unplugged A4988 and applied power - line went to 3.3v.  Plugged in another module and line again at 3.3v.  So A4988 faulty.  Now to test again.

[Gina]

Remote focussing now working but it's too coarse so I'll change the number of steps involved in the driver.

[Gina]

Done that.  Hopefully the fine focus is now fine enough.  Fine is 5 steps and coarse is 50 steps.

The Camera Cooling and Dew Heater controls also work fine so I think I'm now ready to assemble the ASC.  Whether I can get it installed outdoors depends on how the rest goes and the weather - been having lots of heavy hail showers.

[Gina]

This is the compiling and installing sequence.

[Gina]

Have the ASC half assembled and stepper motor connected to the driver module but the motor isn't turning.  I though I'd tested it but evidently not.  Have to replace it.  Not a great problem - only two screws and four soldered joints.  Might leave it until tomorrow now - been a busy day.

Solid cloud tonight anyway and no sign of any clear nights ?

Edited April 2, 2019 by Gina

[Gina]

Focus motor fixed - just a bad connection.

[Gina]

Been testing the remote focussing.  Set the ASC pointing out of the south window, chose ROI covering the far range of hills and tried the focus controls.  They work well and seem about right for the resolution - I can see the difference a few Fine steps makes.  The focus is achieved with the rack roughly in the middle of its range.  The size of the fine steps at the focus ring is a fraction of a degree - that's how sensitive the focussing is and shows why manual focussing is inadequate.  Next to connect up the dew heater and camera cooling.

Edited April 3, 2019 by Gina

[Gina]

Connected up and tested.  Then concentrated on the rest of the assembly of the casing and mounting on the mast tube.  As seems usual with this project it was 3 steps forward and 2 steps back!  The top outer casing parted at the angle between the cylinder and the cone - fixed that temporarily with silicone sealant.  The 3" dome has developed a small crack from the edge to about a cm up.  Whether that will allow any damp in remains to be seen.  I'll probably erect the mast and ASC this afternoon if it's not raining or worse and I should soon know if I have leakage from the colour changing silica gel.  Plenty of rain, sleet and hail in the forecast for the next week!!! 

Edited April 3, 2019 by Gina

[Gina]

With the ASC assembled I tested the focussing again and it's still working.  I was able to fine focus on the far hill and get a sharper image.  It's certainly a lot better than I got manually.  This is with everything still indoors and looking out to the south.

[Gina]

Here's the full image view and a partly zoomed in one to show how small that zoomed in area was.

[JamesF]

That's so zoomed in you can see the flaws in the on-camera demosaic algorithm :D

James

[Gina]

Taken the rig out and erected it, clamping the mast to the bracket on the observatory north wall.  Next is to sort out the electronics.

[Gina]

Electronics connected and ASC working over WiFi.  Exposure 1ms, gain 0.  Camera cooling is working and current temperature is -10°C.

[Yawning Angel]

Good luck!

[Gina]

Wheeeee....  A bit of clear sky - complete with contrail!

[Gina]

Next door have switched their floodlight on but it's not as bad as before because I have the ASC angled to block most of the light.  There is a bit of clear sky and there seems to be a star and it's well focused.

This is an exposure of 60s, gain 0, camera temperature of -20°C.  Water cooling on and Peltier TEC running at 12v which I think is about optimum.

Edited April 3, 2019 by Gina

[Gina]

Oops - it's started raining.

[Gina]

Shower passed over and dome dried so the dew heater is working well ?

Exposure 60s, gain 100, temperature -20°C.

Edited April 3, 2019 by Gina

[Gina]

Light is now off but almost complete cloud cover though some of it quite thin and stars are showing through.

[Gina]

Exposure 60s, gain 300, temperature -20.5°C.

[JamesF]

Are you able to tweak the focus remotely now?

James

[Gina]

Yes.  Assuming it's still working.  I just need a break in the clouds so that I can see the stars clearly. 

Edited April 3, 2019 by Gina

[Gina]

General thin cloud!

[Davey-T]

1 minute ago, Gina said:

General thin cloud!

I've got his commanding officer here Major Black cloud 

Dave

[Gina]

Gain reduced from 300 to 150 everything else the same.  Been outside and there's no sign of any stars to the naked eye.

Edited April 3, 2019 by Gina