'All Sky' Camera

'All Sky' Camera

Postby Aratus » Sat Jan 21, 2017 5:52 pm

Having seen some interesting applications of 'all sky' cameras, I thought I would give it a go myself.
The base is simply an old plastic paint container. I put in a solid wood disc at the bottom to give it some weight, and to keep the spiders out. There is also plenty of room to put in electronics, batteries etc, in the future if I want a more self supporting unit.
The dome is a 6" diameter sold as a replacement for an underwater camera housing.
The camera is a ZWO ASI120MM USB 2.0 Mono Camera with a 'so called 150 degree lens (it is more like 120 degrees)
Image

My initial experiments failed dramatically as condension, sooner or later, obscures the dome. My solution was a home made heater. I got hold of some glass fibre tape, (the sort used to seal oven doors!) and made a circle of it on the floor of the base unit. I then took 18 inches of 32 gauge nichrome wire and threaded it through the tape at various places to hold it in place. Using a 12 volt system it heats the wire to a temperature of 250C, and required 9.2W on maximum load.
Image
Now, that seems to keep the condension off even when the temperature drops to below freezing. A 10 second exposure seems to show all the stars you can see with the eye. Even the Milky Way shows up.
Image
Leaving it to capture the sky all night shows star trails, aircraft, bright satellites and bright meteors.

Image

This isn't a permanent set up - yet. I simply plug in the 12v supply to my Anti-dew controller, and the camera output to the USB in a laptop. Possible upgrades might be to use a Raspberry Pi and transmit the images to my computer network, and use an internal battery. I can then put the unit anywhere I like.
Last edited by Aratus on Fri Jun 15, 2018 10:59 pm, edited 1 time in total.
I use an 11" reflector (Celestron CPC 1100) and a 3" refractor, (Sky-Watcher ST80) mounted on an equatorial wedge, housed in a 2.2m Pulsar observatory. I use a ZWO ASI 120MM, ZWO ASI1600MC and Canon 1300D for imaging.
Aratus
 
Posts: 870
Joined: Tue Jan 12, 2016 2:17 pm
Location: East Lincolnshire

Re: 'All Sky' Camera

Postby Aratus » Sat Sep 02, 2017 7:08 pm

Time to update this thread.
I've managed to replace the old 'photobucket' images above, which were rendered useless by photobucket.

The main problem with the all-sky camera above is the very expensive astronomical camera which is tied up in the transparent dome. Also that it requires a Windows laptop to run it, and to be affective it needs to be switched on all the time. That not only ties up the laptop which can't be used for anything else, but it is expensive to run, and takes up a lot of room. As I hinted at earlier, one solution is to use a 'Raspberry Pi', which is a tiny computer used for education and projects. The cost about £35. I did try to connect the Zwo camera to the Pi, but I could never get it to work. I felt I was on much safer ground trying to use the Pi's own camera. It only costs £25, but it is not designed for astronomy, and nothing like as sensitive as the Zwo. Anyhow I removed the Zwo and placed the PiCamera in its place. I am using a £7 fish eye lens designed for 'smart phones'. The Pi computer is placed inside the 'bucket'. When it is switched on I've installed the program, 'Samba' on the Pi, and 'Putty' on the laptop in the house. This enables them to communicate with each other. (The Pi has its own wifi.) This means I can operate the Pi remotely from a window on the laptop. The camera is operated by a little program I've made using the Python language, which comes free on the Pi. No problems getting an image in daylight. . . Image
The white ring is a reflection of a silver ring on the lens. I will eventually paint it black. The big problem is going to get an image at night. I'm going to have to really thrash it just to get images of clouds. I think very few stars will be visible.
I use an 11" reflector (Celestron CPC 1100) and a 3" refractor, (Sky-Watcher ST80) mounted on an equatorial wedge, housed in a 2.2m Pulsar observatory. I use a ZWO ASI 120MM, ZWO ASI1600MC and Canon 1300D for imaging.
Aratus
 
Posts: 870
Joined: Tue Jan 12, 2016 2:17 pm
Location: East Lincolnshire

Re: 'All Sky' Camera

Postby Aratus » Sun Sep 03, 2017 2:41 pm

A 3/4 moon lighting the sky didn't help test the new camera, but the result are not too bad. The moon itself was behind the observatory as I took these images. I 'averaged' 10 x 10sec exposures. The resulting image shows Altair, Deneb and Vega - the summer triangle, with Altair above the dome, and Vega being the bright star. I think stacking images is going to be the way forward with this, but doing that automatically using 'Python' is a bit unknown territory for me. I'll have to wait until the moon is out of the way to do any more tests.

Image

One possible improvement would be to remove the Pi's lens, and use a CCTV fish-eye lens to project the image directly on the sensor.
Last edited by Aratus on Fri Jun 15, 2018 11:00 pm, edited 1 time in total.
I use an 11" reflector (Celestron CPC 1100) and a 3" refractor, (Sky-Watcher ST80) mounted on an equatorial wedge, housed in a 2.2m Pulsar observatory. I use a ZWO ASI 120MM, ZWO ASI1600MC and Canon 1300D for imaging.
Aratus
 
Posts: 870
Joined: Tue Jan 12, 2016 2:17 pm
Location: East Lincolnshire

Re: 'All Sky' Camera

Postby Aratus » Wed Sep 06, 2017 4:07 pm

If anyone is interested, this is a photo of the 'Raspberry Pi' computer board, and the PiCamera inside the 'bucket' Both are powered by a single 5v source. Either a mains adapter or a battery.
Image
The computer is set up so it doesn't need a screen or keyboard. The photos are stored on its own memory. The built in wifi means it can be part of a home network. The photos can then be viewed on another computer on the network.
I use an 11" reflector (Celestron CPC 1100) and a 3" refractor, (Sky-Watcher ST80) mounted on an equatorial wedge, housed in a 2.2m Pulsar observatory. I use a ZWO ASI 120MM, ZWO ASI1600MC and Canon 1300D for imaging.
Aratus
 
Posts: 870
Joined: Tue Jan 12, 2016 2:17 pm
Location: East Lincolnshire

Re: 'All Sky' Camera

Postby Aratus » Sat Sep 09, 2017 12:53 pm

The latest developments are an internal battery to run the Pi and camera. Also after much experimenting with different lens' and configuration, I'm back to the original fish-eye lens. So, I've now put in a permanent mount for that lens. It's made out of thick card. I've also painted everything around the lens mounting, black, and I'm blocking the light coming from the various leds on the Pi and battery charger. With less stray light I may be able to add 4 or 5 images together to give a useful image.

Image
Last edited by Aratus on Fri Jun 15, 2018 11:01 pm, edited 1 time in total.
I use an 11" reflector (Celestron CPC 1100) and a 3" refractor, (Sky-Watcher ST80) mounted on an equatorial wedge, housed in a 2.2m Pulsar observatory. I use a ZWO ASI 120MM, ZWO ASI1600MC and Canon 1300D for imaging.
Aratus
 
Posts: 870
Joined: Tue Jan 12, 2016 2:17 pm
Location: East Lincolnshire

Re: 'All Sky' Camera

Postby Aratus » Wed Sep 13, 2017 3:56 pm

After testing the camera, I was still getting reflections from the white base, and some light from the leds. This showed up as a less than dark edge to the image. I've put in some black light baffles to stop the led lights shining up into the dome. I've also taken out one strip of heat resistant glass fibre tape, and re-threaded the nichrome heating wire into the remaining one at the edge. I've painted the base nearest the camera black.
Image
Hopefully that will give a blacker sky and give a better contrast with the stars.
Last edited by Aratus on Fri Jun 15, 2018 11:02 pm, edited 1 time in total.
I use an 11" reflector (Celestron CPC 1100) and a 3" refractor, (Sky-Watcher ST80) mounted on an equatorial wedge, housed in a 2.2m Pulsar observatory. I use a ZWO ASI 120MM, ZWO ASI1600MC and Canon 1300D for imaging.
Aratus
 
Posts: 870
Joined: Tue Jan 12, 2016 2:17 pm
Location: East Lincolnshire

Re: 'All Sky' Camera

Postby Aratus » Thu Sep 14, 2017 10:47 pm

This is the latest image. There are 6 images added together. I don't expect to be able to get a better image with this camera. Adding the images together using the software is the next problem.
Image
I use an 11" reflector (Celestron CPC 1100) and a 3" refractor, (Sky-Watcher ST80) mounted on an equatorial wedge, housed in a 2.2m Pulsar observatory. I use a ZWO ASI 120MM, ZWO ASI1600MC and Canon 1300D for imaging.
Aratus
 
Posts: 870
Joined: Tue Jan 12, 2016 2:17 pm
Location: East Lincolnshire

Re: 'All Sky' Camera

Postby Aratus » Sat Sep 23, 2017 9:45 pm

Tweeking the parameters of the camera, I've managed to get the exposure and brightness just right to see both clear sky and cloud. In this case also a passing aircraft.
Image
There is a function for adding text to the image, so it can be time stamped.
I use an 11" reflector (Celestron CPC 1100) and a 3" refractor, (Sky-Watcher ST80) mounted on an equatorial wedge, housed in a 2.2m Pulsar observatory. I use a ZWO ASI 120MM, ZWO ASI1600MC and Canon 1300D for imaging.
Aratus
 
Posts: 870
Joined: Tue Jan 12, 2016 2:17 pm
Location: East Lincolnshire

Re: 'All Sky' Camera

Postby Aratus » Thu Oct 05, 2017 7:48 pm

I've now added a 'piface' to the Pi! That is another little circuit board which makes it easy to control things using the Pi computer. In this case I can now switch the heater on and off remotely with relays. So if it starts to dew up, then I can easily switch it on and clear it. So that I have a better idea of what is happening inside the transparent dome, I've added a thermometer sensor. By keeping the temerature inside the transparant dome higher than the outside temperature I should able to avoid any dew. At the moment I can switch it manually, but it should possible, eventually, for the Pi to switch the heater on automatically if there is likely to be dew. (possibly!) The camera is now permanently fixed up outside.

I've produced a set of exposures to try out. This one caught the International Space Station, just as the moon started to come into view. Some of the brighter stars are visible too.
Image
I use an 11" reflector (Celestron CPC 1100) and a 3" refractor, (Sky-Watcher ST80) mounted on an equatorial wedge, housed in a 2.2m Pulsar observatory. I use a ZWO ASI 120MM, ZWO ASI1600MC and Canon 1300D for imaging.
Aratus
 
Posts: 870
Joined: Tue Jan 12, 2016 2:17 pm
Location: East Lincolnshire

Re: 'All Sky' Camera

Postby Aratus » Sat Oct 07, 2017 1:12 pm

Although the cloud and moonlight are spoiling observing at the moment, I did catch this 'moon ring' on the camera.
Image
Last edited by Aratus on Fri Jun 15, 2018 11:03 pm, edited 1 time in total.
I use an 11" reflector (Celestron CPC 1100) and a 3" refractor, (Sky-Watcher ST80) mounted on an equatorial wedge, housed in a 2.2m Pulsar observatory. I use a ZWO ASI 120MM, ZWO ASI1600MC and Canon 1300D for imaging.
Aratus
 
Posts: 870
Joined: Tue Jan 12, 2016 2:17 pm
Location: East Lincolnshire

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