Cumulus Support

I'm thinking of re-installing and setting up my webcam, and some advice would be appreciated.

Where we live most of our "weather" comes from the south and west, and in the past I had it facing north as I was worried about the sun's radiation damaging the lens or sensor if it faced south.

Any thoughts and advice on setting it up, whether to go for an indoor or outdoor model would be appreciated!

From a CCTV point of view (as that's my background), if you use an internal camera, it obviously has to be mounted inside, and as result, you will get internal reflection from any windows it sit's behind.
If using an external camera, try to pick a view of the sky that sits below the arc that the sun actually follows, so the sun is not directly in the field of view.
If the sun is in the image, this will cause the iris to close fully, but even in this state, some light comes through and it has the potential to burn the sensor.
Choosing a camera with wide dynamic range will reduce the impact of silhouetting of anything in the foreground.

jon_iz wrote: ↑Tue 23 Jun 2020 12:00 pm Choosing a camera with wide dynamic range will reduce the impact of silhouetting of anything in the foreground.

@jon_iz: As this is your area, are you able to recommend a particular camera, or maybe a detailed spec? My interest is in capturing the sky and distant hills rather than close-up detail.

This is a bit of an open ended reply, i'm afraid, as price ranges are huge new or second hand.

So I'll try and give a bit of a potted history / guidance.
Historically up until probably about 5 years ago, the mainstream production of cameras were all analogue composite video output.
Modern cameras now typically are "IP Cameras" and deliver video usually, via standard format of mjpeg or h.264 compressed video streams requested as an HTTP or RTSP request.
To use with CumulusMX, you need to be able to get it to generate a still and save it some where useful, or FTP it somewhere.
With analogue cameras, the easiest way to do this is use a separate video encoder - this is the method i used, basically as i had both lying around. (My bullet camera is attached to a port on an Axis M7104 encoder, which is able to ftp a jpeg image upto my web host on a schedule).
Many IP cameras would be able to do the same - but if you have one in mind, try and search out a manual and look at the options - good luck if you try this is an unknown Chinese brand!
Many IP cameras will also support 12VDC and PoE - so you don't have to run external power if you have a PoE switch or PoE injector (probably unusual at "home").

So, what sort of camera?
This depends what you are wanting to capture, so i'll just put a list of thoughts, that you can apply to analogue or IP cameras.
Avoid cameras that do no have an auto iris lens (often called a DC lens) - they vary the shutter speed to reduce exposure levels and do not work well externally. Typically auto iris lenses are also vari-focal, meaning you can adjust the field of view. For a 1/3" chipset, a range of 3~9mm (approx 60° to 30°horizontally) will do - anything longer than 9mm will start to restrict the useful field of view. At wide angles, expect some softening of focus at the edges of the image.
Try and look for something with a Wide Dynamic Range or High Dynamic Range chipset - the camera will stand a better chance of exposing the sky.
Standard definition (D1 / 4CIF) and 720p resolutions are probably adequate. 1080p(2MP) and beyond will just generate large images, and you aren't going to use that detail with a "sky" view).
For External use, you want IP65, IP66 perhaps IP68 - increasing cost with numbers - but any will do for the purposes here - but don't pressure wash any of them!

Cameras come in a number of physical flavours:
1.Dome (self contained small dome, camera in fixed attitude, with polycarbonate bubble over the camera and lens assemble. Sometimes called Vandal Domes. These need careful cleaning as they will attract more surface deposits with time and will scratch if rubbed with a cloth)
2.Bullet (self contained, cylindrical or square bodied, often with sunshield and a flat window over the lens assembly, camera usually has an integral bracket to set the attitude of the camera)
3."Box" - discreet lens, camera, housing and bracket as separate components - unusual these days and large!
4. PTZ - usually in a dome format these days.
For this application, i'd discount 3 on cost and size and 4 on cost and not suiting the purpose - 4, as really you just want a static view and often these don't look more than 5~10° above horizon anyway.

So, 1& 2 - you can find them with and without IR LEDs. Typically anything designed for external use will delivery good lowlight, but the images will get noisy below 0.5Lux and they tend to lose sensitivity as the light level drops. Most will switch to monochrome under these conditions.
Cameras with IR LEDs enhance performance in low light by supplementing the available visible (or zero ) light with infrared - typically a covert 800~900nm wavelength, which will assist the camera in resolving some detail over 10~30m, depending on the number of LEDs, their diffusion angle and age (they degrade over time). If you are looking only at the sky, IR LEDs will serve no benefit.

Most dome or or bullet cameras with IR will suffer some internal reflection when the IR is active or with high incident light in the day. (The old thing i have put up does this in the day - you can see a series of dots in the image, this is caused by internal refection of sunlight in the LED diffusers). The exception to this is where the IR is a does not use the same "window" as the lens, so on a bullet camera, it's a two piece window with a physical barrier between the two pieces and this stops the internal reflection from the LEDs. Split windows are expensive and rare.

The biggest challenge for most people will be adjusting the focus, as usually you need a monitor available to do this, but you can do it with a laptop connected to the video stream for an encoder solution or IP camera - for an old analogue camera, a TV with CVBS video input can be used. When you focus the camera - do it at night or close to - you will be able to see the monitor, and the aperture is wide open on the camera lens giving a minimum "depth of field", looking at something with a defined "edge" at >10m away. When focused under these conditions, it will also be focused in the day.

Hope that helps!

Thanks for such a comprehensive reply, Jon. I have used a ptz dome IP camera in the past (mounted inverted) which gave reasonable results, but invariably the mechanical parts stopped working after 18 months or so. So I will be looking at options 1 & 2 (most likely 2) IP camera with auto iris lens - either poe or separate power.

One question: is the chipset size (you mention 1/3") important?

Thanks,

I've got one of these:

https://www.amazon.co.uk/gp/product/B07 ... UTF8&psc=1

I don't allow it to have a public view though, I just keep my Foscam FI9900P for that.

The PTZ cam is an absolute monster though! I can confirm The 250m night vision though, I would even argue it can manage 300m. Optical zoom during daylight hours is absolutely awesome!

You can also tilt upward, not many PTZ's do that.

freddie wrote: ↑Tue 23 Jun 2020 10:24 pm Thanks for such a comprehensive reply, Jon. I have used a ptz dome IP camera in the past (mounted inverted) which gave reasonable results, but invariably the mechanical parts stopped working after 18 months or so. So I will be looking at options 1 & 2 (most likely 2) IP camera with auto iris lens - either poe or separate power.

One question: is the chipset size (you mention 1/3") important?

Thanks,

1/3" is typically the format used on analogue cameras.

Most IP cameras are probably 1/4", 1/6" or 1/2.8" these days, depending on sensor, and resolution. Check the camera specs, if they use and integrated lens, to establish the fields of view.
However, a larger sensor, with lower resolution will generally be more sensitive as the photo-transistors are bigger, which means they can accumulate a greater charge for a given exposure. The more you pixel cram into a small area, they less sensitive they get. Sensor technology is improving rapidly, allowing more low light sensitivity by longer exposure.
(Though that can't be used in the environment I work in, as objects move too fast)

Some really useful advice for someone buying a camera, many thanks, but what about siting it and getting a good wide angled view of the sky without the sun blasting the sensor?

Geoff

Mapantz wrote: ↑Tue 23 Jun 2020 10:30 pm I've got one of these:

https://www.amazon.co.uk/gp/product/B07 ... UTF8&psc=1

I don't allow it to have a public view though, I just keep my Foscam FI9900P for that.

The PTZ cam is an absolute monster though! I can confirm The 250m night vision though, I would even argue it can manage 300m. Optical zoom during daylight hours is absolutely awesome!

You can also tilt upward, not many PTZ's do that.

Yes, not unusual to see 30:1 on some of the starlight camera blocks now. Though heat haze tends to become a problem at long ratios on a hot day, as does vibration, if the mounting is not completely static. This is an inverted PTZ camera, rather than a PTZ dome.
250m is not unusual, for long range IR - interesting techniques need to be employed to try and manage the "hot spot" if you are looking at something close to the camera under IR though.
The stuff i am generally working with now has to deliver images with enough contrast to pick out a human at 500m in zero visible light applications, so IR needs to work beyond this comfortably - typically 750~1000m, so a often supplementary arrays to what is on the camera are added. I can guarantee you will have seen these travelling around the country....

geoffw wrote: ↑Tue 23 Jun 2020 11:00 pm Some really useful advice for someone buying a camera, many thanks, but what about siting it and getting a good wide angled view of the sky without the sun blasting the sensor?

Geoff

Either pointing north in the northern hemisphere, or if you wish to point south-ish, keep it below the arc that the sun follows.
As the sun becomes lower in the sky in winter, the intensity is less, so cameras are more tolerant if you catch it at the extremes of the day. I've seen direct summer sun leave burns on sensors after prolonged focused exposure.

North is no problem but the most interesting weather here usually comes from the south or south west! Never mind I think I win invest (not really the best word!) spend some cash on a wireless camera, and give up poking my little USB camera at the window!

If pointing south is one option to accept that you will eventually get some sun damage (fading of colour, or worse) to the camera and so buy a cheaper one that you replace more often?

That a good idea!

I've got 1 cheap IP cams facing East & West. Probably been up for about 4 years now.

Both are angled up at about 30°, and certainly the sensor gets direct sun.
I found that aiming them any lower simply didn't get a decent sky & cloud view.
All I would get is a birds eye view of the neighbors yards.

Despite this there's no obvious sensor burning visible on the images.

They are both managed by iSpy software, which does the FTP uploads & also creates Time lapse MP4's.

Static cams viewable here:- http://weather.inverellit.com/webcams.htm

And a couple of time lapse's here...
http://weather.inverellit.com/video/1_T ... -24-16.mp4
http://weather.inverellit.com/video/2_T ... -00-06.mp4
http://weather.inverellit.com/video/2_T ... -00-09.mp4

The second has the Sun within the frame, & the reflection rays are from Spider Webs that I haven't got to removing yet.
The third is the same cam after the sun is out of view. No sensor damage visible, just the blur of some web in the bottom left.

These are cheap cameras, circa under $100.
My security run 14 Hikvision cameras & would say as far as cost/value & suitability for task I'm pretty impressed with these cheapies.

Cheers.

Cheers Phil and all,

This has been really interesting. With my original camera (internal USB pointed out of a window) I used Yawcam to run it. I think it is time I updated my kit.