All Sky Camera Revisited

[Gina]

CCTV cameras are not usually sensitive enough to show stars.  As a comparison, I'm using an astro camera and 60s exposures.  CCTV cameras are limited to 1/25th second or maybe 1/50th.  PAL TV standard uses two interlaced frames of 1/50th second each.

[CedricTheBrave]

4 minutes ago, DaveL59 said:

yeah hence am sorta following that route too, I have a thread "El cheapo sky camera" if you can find it, shows what I put together.

I'd say at £96 that one's pretty expensive for what it is, given a cctv IP board camera is in the £24 region with a fisheye lens, would just need the housing. OK you can't pan/zoom but would you need to? Mine stay in a fixed aim unless I decide to adjust that manually and give 150-170 degree view from a 2.5mm or 2.1mm  lens. That lens likely would only go to 120 degree and the extra elements to enable the zoom range would probably not be good for astro, too much loss if nothing else.

If that one is something you think worth a go, factor in swapping out the dome for a clear one if you can find a suitable one, else you'll see almost nothing at night  

i was only really using it as an example i have looked at quite a few that have clear domes so the hardware side of it looks useful. i will checkout your thread as well thanks.

[Gina]

This is a more likely shape for the bottom part.

Edited October 1, 2019 by Gina

[Gina]

The ASC can go on the south side of the ROR at the apex with a hole in the shiplap just to one side of the internal frame members.  This was what I did once before with an earlier version but with just wires going through the shiplap boarding as can be seen in the second photo of the inside of the roof.

Edited October 1, 2019 by Gina

[Gina]

This shows the inside of the roof with the damp-proof membrane pulled down a bit to show the boards.  There is already a gap of about an inch with rubber roofing overlap that provides ventilation.

[Gina]

The TEC1 12703 Peltier TEC has arrived and I am testing it.  I have the current thermal jacket on the camera though this will be changed.  Running off my standard supply of 13.8v.  Camera temperature started at 33°C and has gone down to just 5°C, a drop of 28°C.  I don't think that's too bad for single stage cooling with just air cooling.  TEC is drawing just over 3A.

[Gina]

[Gina]

Gradually working through the design of the various parts and fitting them together.  Here is the assembly as far as I've got.  Camera housing is shown in clear blue, camera, lens and cooler housing in solid white and the fan and heatsink/cooler are not visible.

[Gina]

Cooler made visible and all plastic clear blue.

Edited October 3, 2019 by Gina

[Gina]

Dome added to assembly.  This shows that the dome is quite close to the camera housing extension that accommodates the USB plug but may be alright - just.  There is also the question of the remote focus gears still to be worked out (unless I go for preset focus).  On top of all that I have to sort out how the camera housing id going to be fastened together and to the base part.

Edited October 3, 2019 by Gina

[Gina]

This is an option.

Edited October 3, 2019 by Gina

[Gina]

Lastest...  Beveling and holes for attaching camera casing parts to base with screws up through base.

Edited October 4, 2019 by Gina

[Davey-T]

Looking good Gina where are we now on revisions ? have to come up with a catchy name for the final version the ASC MkV XL Super or some such 

Dave

[Gina]

😁

I've lost count of version numbers!  Have to check but probably 8 or 9.

[Davey-T]

3 minutes ago, Gina said:

😁

I've lost count of version numbers!  Have to check but probably 8 or 9.

Better make it the Mk 10 then 

Dave

[Gina]

Part of outer housing added.

[Gina]

This is individual item.  It isn't finished - there are various holes to be added including the air vents and their hoods.

Edited October 4, 2019 by Gina

[Gina]

Base extended out to the outer housing and screw holes added.  Screw holes also added to outer housing.  That attaches the housing and base.

[Gina]

Camera , lens and camera housing shown as material with outer housing and dome shown in clear blue.  Oops the dome has moved in the assembly - that won't happen in the real thing - it will be screwed in place.  Still need to design the air intake, attachment to ROR and the air vents plus holes/spaces for the wires.  But gradually getting there, I reckon.

Edited October 4, 2019 by Gina

[Gina]

I don't know if there's room for the remote focus stuff - it's pretty cramped.  I could make the outer housing bigger but I might just try it with preset focus.

[Gina]

Two possibilities for the air intake - flexible tubing (I have 2" which matches the fan size) or 3D printed and rigid.  Still have to decide but I think a 3D printed part would probably look better.  The wires/cables can go through the air intake.  I may combine the roof mounting with the air intake if I go for 3D printing.

[Gina]

Been trying to print some of these parts but my printer is playing silly beggars!!

[Gina]

Made channels in the base for wires and cables.  Fan, Peltier TEC and USB cable for the camera.

[Gina]

Air intake and ASC mounting.  The rotation is to allow for the observatory not being aligned east-west.

 

Edited October 4, 2019 by Gina

[Gina]

That bracket & air intake seemed far to big once printed so I've designed a narrower, better looking part.  This will also include a rotating joint so that I can align the ASC to put north at the top of the picture rather than guessing the angle.  I have yet to put the holes in.

Edited October 6, 2019 by Gina