[HN Gopher] Roll Your Own All-Sky, Raspberry Pi Camera
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Roll Your Own All-Sky, Raspberry Pi Camera
Author : sundarurfriend
Score : 257 points
Date : 2023-10-11 21:28 UTC (23 hours ago)
(HTM) web link (spectrum.ieee.org)
(TXT) w3m dump (spectrum.ieee.org)
| malfist wrote:
| I've been in the process of planning a backyard observatory some
| and have been looking at all sky cameras to measure clouds,
| seeing and sky glow.
|
| This project looks really promising, especially if it has an
| ascom driver
| teamonkey wrote:
| https://github.com/IanCassTwo/rpicam-ascom-alpaca
| destitude wrote:
| https://github.com/aaronwmorris/indi-allsky has INDI drivers.
| ShadowBanThis01 wrote:
| Is there a MIPI camera that doesn't suck?
|
| I have every official Pi camera, and they are all just terrible.
| I would never use them for anything artistic, when it's easy to
| get far-superior results from even a cheap regular camera or used
| SLR.
|
| I'm just curious if there's a very-high-quality camera with a
| MIPI interface. Thinking it through... I only really care about
| video. Even if it's only HD resolution, something with excellent
| light sensitivity & low noise would be great.
| blacksmith_tb wrote:
| There are some pretty fancy-looking industrial cameras that
| support MIPI, like the Alvium line[1] - but I suspect they are
| spendy...
|
| 1: https://www.alliedvision.com/en/products/camera-
| series/alviu...
| ShadowBanThis01 wrote:
| Thanks. I guess at some point the value proposition is
| antithetical to that of the Pi itself...
| geerlingguy wrote:
| Yeah the problem is optics (the more important part of
| getting really good images) are expensive, and few
| companies make decent lenses that target tiny sensors.
|
| So you're stuck with the little optics included with the
| tiny hobby cameras from Pi or ArduCam (et all). They're
| okay for some purposes but a lot worse than even a cheap
| SLR/Mirrorless lens.
|
| The best results I've gotten are with the C-mount camera
| module, an adapter, and a wide angle Sony, Nikon, or Canon
| lens--all of which cost in the hundreds :)
| giantrobot wrote:
| Thrift/antique stores are a place to look for old lenses
| on the cheap. If you've got a C-mount adapter for your
| sensor you can mount the lens on it. Then you can
| manually focus it and epoxy it on the right point.
| ShadowBanThis01 wrote:
| I have the C-mount module and a Canon security-camera
| lens with zoom, focus, and aperture settings.
| Disappointingly, it still sucks.
|
| I know there are excellent C-mount lenses, because I shot
| a great-looking movie on a Bolex with them.
| casylum wrote:
| Often it's the lens that results in poor quality images. You
| can get a RPi sensor with CS mount and add your own lens of
| your choosing. It's been a huge upgrade in quality and is
| relatively easy to do.
| JKCalhoun wrote:
| There is also a lot of "secret sauce" that Apple and others
| do to the raw image data that comes off the sensor. I don't
| doubt much better quality could be eked out of the RPi
| cameras if there was a determined effort to do so.
| wkat4242 wrote:
| They suck at video. Take stills and they do a lot better.
| Roark66 wrote:
| >Is there a MIPI camera that doesn't suck?
|
| No there isn't. Sorry. I've tried them all and their dynamic
| range sucks so bad....
|
| Anyway, who thinks otherwise, I recommend you see the same non-
| ideally lit scene with for example a modern "analog" fpv camera
| like Foxeer Nano Toothless 2 (a starlight 0.1lux camera that
| maintains it's great dynamic range in full sun).
|
| The only mipi camera that has a shred of a chance to compete is
| starvis IMX327LQR. On paper it should be pretty good. I'm
| planning to test one at some point.
|
| Also, the cameras built into various Cctv Ip cameras one can
| buy from China are pretty good, but good luck getting them to
| work with anything other than the original equipment.
| ShadowBanThis01 wrote:
| Ha, thanks for the reply.
|
| Tangent to your IP-camera comment: I replaced all my old SD,
| composite household security cameras with cheap-O TVI
| cameras, and I am impressed at how well this oddball HD
| format works over the same coax cables.
| teamonkey wrote:
| For light sensitivity there's an Arducam IMX482 MIPI module.
| Unfortunately you don't have a lot of control over it and can't
| take long exposures, but it's probably fine for HD video. Every
| other cheap low-light module I've seen is hobbled in some
| crucial way, either at the hardware level or drivers.
| dekhn wrote:
| I haven't found any decent MIPI cameras. Instead, I buy machine
| vision cameras from Mindvision. USB3 or GigE connectors.
| porphyra wrote:
| How do you prevent the sun from damaging the sensor over time?
| wkat4242 wrote:
| I've had a pi 1 camera looking out at the horizon for many
| years and it didn't really get damaged.
|
| Don't forget the default lens is tiny. It doesn't really
| capture a ton of light.
| TheSpiceIsLife wrote:
| If you know the diameter of the lens, and your areas
| insolation, you could work out it's annual solar energy
| exposure in watts yeah.
| jws wrote:
| I had one pointed east at the horizon the show a lighthouse a
| mile away using an old spotting scope. Worked ok until the
| sun made its way around to rise in frame. Now everything is
| greenish. I think with sufficient magnification you can cook
| your color filters or maybe the sensor wells under the
| filters.
| gmiller123456 wrote:
| I have had an all sky camera out for about two years now
| without issue, also never heard of anyone having an issue. The
| first I've heard is the comment above about using a spotting
| scope, which would have a much larger objective than a typical
| all sky camera, and sounds like the Bayer array (the filter for
| color imaging) was damaged. I imagine most sensor manufacturers
| know their sensors will get pointed at the Sun and some point,
| and are designed to account for it. Especially since pictures
| of Sunsets/Sunrises are pretty popular.
|
| The Sun is actually pretty small (1/2 a degree), and the image
| of the Sun will only occupy a given pixel for about 2 minutes.
| The next day, the declination of the Sun will change, there may
| be some overlap in the pixels it falls on. But over the course
| of a year, the amount of time a given pixel will see the actual
| image of the sun is pretty short, likely less than 10 minutes
| for the worst case near the solstice. And the pixels getting it
| near the equinox will probably only get hit for 4 minutes a
| year, and some not at all. So they're not really taking the
| beating it may seem.
| mathgaron wrote:
| I helped build a similar setup a "long" time ago to build a sky
| HDR database. We had over 40k images across hundreds of days.
| The longer exposures definitely did not help (even with a ND
| filter) and by the end the camera had some broken pixels along
| the sun trail. Nothing noticeable visually, but likely not good
| for computer vision purpose. If we were to redo this it would
| be definitely a valid concern to address.
| destitude wrote:
| Mine has been going on 4 years now with zero issues with the
| camera (ZWO 178MC). The acrylic domes however are a hot mess.
| Frequently have to replace them. Really need to find high
| quality glass domes preferably with anti-reflective coating.
| aiunboxed wrote:
| How does your image / video processing pipeline look like ?
| jws wrote:
| Having done this...
|
| - don't make your camera the highest thing around. My dome was
| showing scratches. Eventually I got a nice photo of the inside of
| a juvenile bald eagle's talon. A bird's gonna perch where a
| bird's gonna perch. Sacrifice some sky and put a better perch
| next to it.
|
| - the manual focus cameras seem to be temperature dependent.
| Maybe get something that can be auto focused or add a heater to
| control night time lows.
|
| - for long exposure low light work, you may find you get much
| better pictures in very cold weather. This relates to charge
| leakage in the sensor. If you decide to try keeping your sensor
| cold, consider condensation. Maybe have something in there that
| is colder.
|
| - also for long exposures, the noise in the image from leakage
| tends to be device pixel specific. You can make a dark view map
| at a given temperature and use it to denoise your images. You'll
| need a shutter though, or do something clever with multiple
| frames as stars move around to get "darkest sample" or something
| fludlight wrote:
| > Maybe have something in there that is colder
|
| Such as?
| smilespray wrote:
| John Riccitiello's heart?
| car wrote:
| Peltier element
| Renaud wrote:
| I would guess a Pelletier element?
| andruby wrote:
| there are astro specific cameras with a cooler. Peltier +
| heatsink.
| dylan604 wrote:
| I've definitely run into the long exposure heat issues. In my
| hemisphere, the central part of the Milky Way is best viewed
| during the summer. In my local part of the hemisphere, its
| ridiculously hot at that time. Even 20s exposures will be
| noisy. I have a smaller pelican case that I've punched a hole
| in for the lens to sit outside the case, and then rigged a
| bunch of those reusable freezer packs for coolers inside. Then
| covid happened, and I now no longer have a car. To this day, I
| haven't taken it anywhere to test it out. Now, I'm really sad
| that I just realized how long it's actually been since I've
| imaged the sky. <wipesAwayTears>
| Yhippa wrote:
| Do you have your pictures or videos posted anywhere? Trying to
| decide if the juice is worth the squeeze.
| destitude wrote:
| I've had zero issues with ZWO cameras that have a manual focus
| lens attached to it and have had air temps from 95F to -45F.
| tecleandor wrote:
| Regardiing condensation, if you can make the case kind of air
| tight, maybe you can either fill it with nitrogen, make a light
| vacuum, or pre-dry the air inside (I remember some tricks to
| avoid condensation in underwater cameras that consisted in
| storing it open in the fridge for some hours or something like
| that, to have drier air inside, I'll look for that again...)
| mchanson wrote:
| Throw desiccant in there if it's pretty airtight.
| gmiller123456 wrote:
| The Pi cameras might seem like a good choice because they're
| cheap, and might be a good way to start. But with all of the work
| required to build, install, and maintain one, the cost of the
| camera is a drop in the bucket. I used a much better camera from
| ZWO (ASI462MC) for about $300 (I actually ended up building a
| second one with the ASI462MM (monochrome)). It even comes with an
| all sky lens. IMHO it doesn't make a lot of sense to cheap out on
| the camera with all the effort involved in building one. I also
| needed to add a short length of Nichrome wire (1amp at 12v) to
| fight condensation.
|
| I started with the color camera, but had to give up on any real
| meteor detection due to the amount of light pollution, and the
| fact that I live directly in line with the airport in Louisville.
| I built the second monochrome version, since the monochrome
| versions are roughly 3x as sensitive, hoping it'd be better at
| detecting meteors at shorter exposure lengths. But it still
| required exposures of a few seconds, much longer that you're
| typical meteor. So, now I just have two all sky cameras doing 20
| second exposures. The monochrome one will still pull out the
| Milky Way from my Bortle 7/8 skies, so I just like the pictures
| it takes and don't plan to change it.
| malfist wrote:
| You're doing astophotography is Louisville? I'm doing it in
| Lexington! We should chat
| bloopernova wrote:
| I'm definitely late to this thread, but I wanted to ask: do you
| know how much of the world is covered by sky cameras? I was
| just envisioning a google maps kind of interface where you
| could grab shots from people who share their images.
| gpt5 wrote:
| Anyone knows how did they make the beautiful diagrams?
| asynchronous wrote:
| This, diagrams and imagery were top notch.
| interloxia wrote:
| The images are credited to James Provost, a technical
| illustrator.
|
| https://jamesprovost.com/
|
| He has a bunch of interviews at
| https://technicalillustrators.org/ (which he co-founded) but I
| didn't find an interview of him.
|
| On his blog in 2014 he notes in passing some of the tools he
| uses. https://jamesprovost.com/blog/surface-pro-3-for-
| illustrators
| dheera wrote:
| I really wish RPi would come out with a truly HQ camera.
|
| Their "HQ" camera is really a LOW quality camera with a shitty
| sensor that isn't even micro-four-thirds. The lens choices are
| abysmal. I want to see at LEAST APS-C or better yet full frame.
| Considering a full-blown mirrorless full frame camera costs $2400
| it shouldn't cost more than $1000 for sensor only, and I'm 1000%
| willing to pay for a hackable, programmable full frame sensor
| especially for night sky photography that can accept the vast
| variety of full frame lenses already available.
|
| There's the Sony QX1 which comes close to what I want but sadly
| they didn't continue that or produce them anymore.
| Tepix wrote:
| The camera is good for its price. If you want a MFT sensor, why
| don't you use something like a Lumix G9 and connect it to the
| RPi via USB? It's a lot less than $1000 these days.
| teamonkey wrote:
| I do think the HQ camera is due an upgrade, though I'd prefer a
| proper low-light camera, ideally Sony Starvis.
|
| Although you can buy cheap Starvis modules you don't have full
| control over the exposure time and/or can only shoot in a
| compressed format. The HQ camera is well-supported with good
| drivers, like all Raspberry Pi hardware, which is why people
| still use the HQ Camera for cheap astronomy projects despite
| having a small sensor and poor low-light performance.
| dheera wrote:
| Full frame cameras typically perform better than "low light"
| cameras with small sensors. Everything else equal, bigger
| collection area trumps everything else, simply because more
| photons means better SNR under shot noise assumptions. SNR of
| a pixel scales with sqrt(average number of photons
| collected).
|
| When your full frame sensor has 25X the physical area as a
| small sensor, that's hard to beat. You can't easily get a 25X
| increase in number of photons collected on the smaller
| sensor. There are only so many photons that hit it. You can
| engineer the hell out of the silicon, but the fill factor
| multiplied by quantum efficiency of the sensors is already
| much higher than 1/25 so there is no theoretical room for a
| 25X improvement even under ideal assumptions. You can
| increase the number of photons that hit it with bigger,
| larger aperture lenses, but beyond f/2.0 or so you start
| hitting limits with our current optical technology in
| correcting chromatic aberration and other issues, and it will
| take miracles to get a 25X improvement on the latest state-
| of-the-art optics.
|
| Sony's full frame sensors also have the same back-illuminated
| design as their Starvis-branded sensors, by the way, so that
| part is not unique to Starvis.
| justin66 wrote:
| Have the Raspberry Pi people done anything even similar to the
| release of a $1000 part? It doesn't really seem up their alley.
| ianburrell wrote:
| Full frame cameras are below $1000. The sensor is probably
| quarter of that. But your camera module for Raspberry Pi will
| cost more than $1000. You save some by getting rid of the
| camera display and buttons. But you still have to design the
| camera control board, the lens mount or lens, and the housing.
| You are doing it on small scale, while the camera makers on
| doing it at large scale and with lots of expertise.
|
| This is why everyone who wants better sensor buys a camera and
| attaches it to Raspberry Pi.
|
| I am surprised that there isn't a 1" camera module, that is
| natural place for better sensor but still fits on board and
| could use C-mount lenses.
| dekhn wrote:
| The HQ has a C-mount so you can put any C-mount lens on it. And
| there are _plenty_ of options in that space.
|
| In my case, I simply can't stand the raspberry pi's camera
| connector so I buy my own "industrial machine vision" cameras
| with C-mount. In my case I found the Mindvision line to be the
| best, I connect with either USB3 or GigE (both of which are
| much nicer cables than the Pi camera connector) and use the
| Mindvision SDK (it's not a uvc device, instead you write some
| python that interacts with the camera, giving you deep level of
| control).
| omneity wrote:
| Slightly off-topic, but did anyone ever run a sky camera with a
| vision model that recognize what it sees?
|
| Like Meta's SAM.
| teamonkey wrote:
| Plate solving - identifying constellations and deep sky objects
| by the relative positions of stars - is a pretty common part of
| astronomy software and possible on a raspberry pi. For example
| https://github.com/dstndstn/astrometry.net
|
| I'm not aware of anything that can, say, identify a meteor and
| differentiate it from a plane or satellite, but I'm sure it's
| possible.
| destitude wrote:
| https://github.com/aaronwmorris/indi-allsky is far superior all
| sky software. Also supports basically running the software on any
| linux based system not just a pi. Have mine running on an odroid.
| adolph wrote:
| _My next thought was that if I had a bearing on that luminous
| streak, and if at least one other person in my region also had
| such information, we might be able to triangulate on it and
| narrow down where any landing zone might be._
|
| It seems like deploying these in pairs at a minimum would make
| sense. In addition to adding spatial information, it gives you a
| backup for any observations at all.
|
| The illustrations are great. Reminded me of how the storage disk
| from the starhinge in Stephenson's Anathem must have looked.
| tivert wrote:
| It would be neat if someone wrote the software to turn something
| that into an astro-navigation device like
| https://airandspace.si.edu/collection-objects/sr-71-astroine....
| mthoms wrote:
| Canadian checking in; Has anyone ever built a cost-effective
| outdoor camera (pi-based or otherwise) that can withstand extreme
| cold (~ -35c)? Or, are there any off the shelf products that
| don't cost an arm and a leg?
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(page generated 2023-10-12 21:02 UTC)