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Re: 'All Sky' Camera

Mon Oct 16, 2017 10:56 pm

A few new developments - all in the software. I discovered a way to annotate the image with information without doing it across the image. The four corners can be used for that purpose. I've also overlayed a dark blue background, and brown border to the lens. I've also taken off extraneous light from the camera itself, and sources of light pollution by subtracting a 'dark frame'. This is all done using a image library for Python.

Last edited by Aratus on Fri Jun 15, 2018 10:55 pm, edited 2 times in total.

Re: 'All Sky' Camera

Mon Dec 11, 2017 5:53 pm

Further developments. The camera has been replaced by an earlier PiCamera 'modded' with a proper all-sky lens. (modmypi) The camera unit has now been elevated above the observatory dome, and due to some forestry work to my west, I can now see the sunset! The camera continues to be useful in monitoring the skies. :D

The only problem now is that it takes a step ladder to bring it down, and wiping/cleaning the transparent dome is a major operation. Tip-toes with a paper towel no longer does it. :(
Last edited by Aratus on Fri Jun 15, 2018 11:04 pm, edited 1 time in total.

Re: 'All Sky' Camera

Wed Dec 13, 2017 12:13 pm

I admire people who try different things but i don't think I will bother

Re: 'All Sky' Camera

Wed Dec 13, 2017 6:03 pm

EIZO wrote:I admire people who try different things but i don't think I will bother

Thank you. For me it is great help, and well worth the effort in making it work. I can monitor when the sky clears from inside the house, and get outside at the first opportunity. It beats having to get up, go outside and check the sky every so often. This way I can see tell the very moment the cloud has cleared from the comfort of a desk or even my armchair. We get precious little clear sky time, and this way I can maximise every minute.

While I'm in the observatory I can see little of the sky, and this camera warns me when cloud is approaching. For instance, it enables me to decide if it is worth doing a long series of exposures, or not. If it does cloud over, I can go inside and check what happens next while I do something else. It beats standing outside in the cold waiting for the cloud to clear.

As an added bonus it will record a bright meteor or bright satellite/ ISS passing over. Also various atmospheric phenomena like sun arcs, moon arcs/rings, alpen-glow and good old rainbows and even lightening.

There is also the satisfaction of constructing something yourself, and learning new skills.

Re: 'All Sky' Camera

Fri Jun 15, 2018 11:19 pm

A few new developments.

The software now automatically works out whether the sun has set or not and changes the parameters of the camera accordingly. So the camera now operates fully automatically.

Next, the 'light shield' is now incorporated into the camera unit, meaning the housing can come straight off without any wires or anything getting in the way. The other improvement is a fan to cool the Raspberry Pi down in hot weather. That transparent dome acts as a bit of a greenhouse. The fan is automatically controlled by the Raspberry Pi using a spare relay on the 'piface'.


Another development is that the software now takes full size photos (1200 x 900) of the sky at dawn and dusk, and copies them. It should be interesting to compare them throughout the year.

Re: 'All Sky' Camera

Fri Oct 12, 2018 11:54 am

I really like this project idea and how you have documented it with these posts. It's great!
I was thinking about creating something similar myself, do you have a website that collates the build that you have done, with equipment and software used?
I'm a software engineer, so it should help if coding is required.
How's it coming along?

Re: 'All Sky' Camera

Fri Oct 12, 2018 6:07 pm

I haven't got a web site or anything that describes building an All Sky Camera from scratch. As you can see , it is mostly from bits of scrap. Using a Raspberry Pi and a PiCamera does have its limitations, but I've recently used image manipulation in Python to add 5 images together which brings out all the 1st magnitude stars.

Basically it uses a Raspberry Pi - and an adapted PiCamera. The one I used eventually was this one
The temperature in the transparent plastic dome is measured by the simple DS18B20 Temperature Sensor.
To provide control of the heating element (to stop dew formation), and to give the poor enclosed Raspberry Pi some cooling with a fan, I use the PiFace https://www.modmypi.com/raspberry-pi/relays-and-home-automation-1032/relay-boards-1033/piface-digital-2-io-expansion-board-model-b-plus There are other boards with relays which would do just as well.
Eventually I fed a 12v supply to the housing, and used a cheap car USB socket which gives out 5v for the Raspberry Pi, and 12v for the fan and heater. The latest Raspberry Pi 3 uses a little bit too much power for the USB socket, so I use an old Raspberry Pi 2. Another alternative is to use a Raspberry Pi Zero, which as well as using less power is cheaper and smaller. The images it produces are kept on the Pi memory and read by a PC on the same wifi network.

The housing is an inverted plastic paint container. The dome is a cheap one used for an underwater camera.

I just use Python to program a routine to take the photo, control the fan, and heater. I'm just learning to use it as I go along. All the documentation for the camera is here, along with examples of python code. https://picamera.readthedocs.io/en/release-1.13/install.html

If you would like to build something similar then start with getting the Raspberry Pi (zero?) and the camera, and learn to take photos using python. Then you can build it into a container fitting the temperature probe, heater and fan. You need some kind of relay board for the fan and heater, but the probe connects straight to the Pi. Some nichrome wire on a piece of oven seal cloth for the heater.

If you have any questions, don't hesitate to ask. Your questions and my answers will help others who want to give it a go. The chances are that you could come up with different or better solutions than me.
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