el-cheapo sky camera

[DaveL59]

so, something I had thought about for some time, but got new inspiration from reading Gina's all sky camera revisited thread, I decided I'd have a go at re-purposing one of the mini IP CCTV units I have laying around. It's a tiny mini cube with Sony IMX291 starvis sensor with WiFi and micro-SD capabiity and HikVision compatible, sourced from AliExpress a year or more ago. I had a few of these but replaced now with Annke HikVision cube types for the main CCTV system.

I will say that these mini cams are not weatherproof so I'd need some means of housing it if I want it aiming up at the sky and that's one reason I'd not got around to it so far. I do have one of these outside as a hedgehog cam, under a makeshift rain shield (an old ready meal container lol) and looking downward, all I did with that one was to cover any ingress points with silicone dielectric grease and 6 months down the road its still working great 🙂

So, how to test this sky cam idea. Well I purchased a dummy CCTV dome off ebay for a couple £ with the plan to install one of these mini cubes into it which has a 2.8mm starlight lens with IRcut filter afixed (no auto IRcut in these tiny cams).  Didn't think to take any piccies as I did this, but easy to figure out. I used a metal bracket under one of the securing screws inside so the camera is held central and coiled the cables under it in the housing. Hole drilled in the lower section to feed the LAN cable in and then dielectric grease in the connectors just in case. Add a silica gel pack and duct tape over the hole, then clear RTV around the clear dome and the top plate and there you have it, a cheapo test rig...

Now I will say that the dummy dome is pretty poor optically, its not nicely smooth so there are ripples in the view and more so at the very top of the dome. But this is a test rig to see if this might work. Wasn't expecting something fantastic at that price, my expectations are low in terms of this "project" at this stage 🙂

The other issues I have to deal with are:
   A large oak tree that will obscure the view to the SW and could well add a sap drip issue over time;
   IR lighting for the security CCTV setup, can't shift those either so need to try shielding some of the impact to the sky image;
   Camera limitations: 1/25s slowest exposure, for example

The garden is reasonably dark so in theory this may work ok, unless folk turn their garden floodlights on of course, time will tell...
 

[DaveL59]

Not sure how you in-line the pics so they're all at the end 🙂

Anyhoo, initial testing shows that the clarity thru the cheapo dome is variable, with wobblies that can be seen in the focus of the oak tree. Still, an image of the sky can be had which is the aim of the game 🙂 Focus could do with a tweak too but not so easy now its set up.

At the moment, with the moon so bright only a few bright stars show but that's not too bad and about what I was expecting to achieve tbh. I had a play with manually setting exposure etc and can get the sky dark, but likely that'd mess the day image quality so have for now left it set to auto exposure, white balance and turned off stuff like BLC, DNR, WDR etc. The old Mk-1 eyeball showed a lot more but no surprise there, plus the moon glow was masking a lot of the sky even to the naked eye, so a fair result with this cam I think.

Not having a spare micro-SD to use I didn't leave it recording (only live watching at the mo)  so no idea if things improved once the moon had set, will have to give that a go at some stage, but can't easily install the SD now the casing is sealed up so would have to record on the PC directly. A handy reason for going the IP route really as I have a switch in the shed linked back into the house for the CCTV systems tho the hog and sky cams are not linked into the CCTV recorder as its already at the full compliment of cameras.

I'm not expecting this would be a great observing rig for imaging etc, just a bit of fun for the moment...

[DaveL59]

Next steps will be:

Upgrade the lens to a wider 2.1mm or 1.7mm to get a wider FoV - on order from Treeye so hopefully 10 days or so I can try those. These are M12 types so I don't expect DSLR or video camera quality images, light grasp of such a small lens will be limited but these will be F2 so might give some useful image (current is I think 2.8mm F1.4)

Upgrade the housing so it has a better dome and makes opening for tweaks more viable. Yeah I plan to pull the internals of this one and replace with the IP one, bit wasteful maybe tho can possible lob that onto the older video feed DVR if I need it later.

Am also considering maybe updating the starvis module to a 5MP one, tho this won't have SD on board, but want to do a bit of research on the sensitivity of the new IMX335 vs the IMX291 I already have. One for the futre at the mo I think 🙂

 

[DaveL59]

ok so looks like the IMX335 might be good, smaller pixels than the 291 but good sensitivity from what I've found. So decided I'd purchase one and have a play. Pretty good price for the module with a 1.7mm lens supplied 🙂

[DaveL59]

hmmm, been looking again at the mk-1 setup and I'm not so sure the filter on the lens really is IRcut, or not effective at least. The tree should be showing green leaves now and they're more purple which makes me think that one had the supposed IR filters I'd ordered separately and fitted but they are only UV. Oh well, too late to mess with it now given its silicone sealed and weather outside is a little damp. One to sort when the better housing arrives and the Mk-1a setup is ready to go...

Will be less of an issue with the 5MP unit is that has switchable IRcut, should be possible to force it into colour/B&W or auto as desired too 🙂

[DaveL59]

So today the postie brought the new dome camera, wow it was a LOT smaller than I thought but...

Stripped it down and its a mini sphere containing the camera unit. Removed the original single-board mini camera module, stripped down the mini-cube and thankfully same board size but mine is a 2.2 board module. But it does all fit with just enough room for the cable connections - I swapped the cable over too since mine is LAN and not AVI. Of course you then realise you shoulda threaded the module end through the base and spring BEFORE closing up the camera sphere... DOH!

Once completed, fitted it to the shed roof just below the peak and drilled a 19mm hole into the shed just below the edge of the roof. Oh no! the LAN end won't quite fit grrrr. So stripped the camera down again and fed the module end out from the inside and reassembled it all once again, not fun up a ladder with tiny screws but made life so much simpler. 

Nice thing is I only need to undo a small allen set screw to unscrew the outer ring and remove the dome so I can get to the camera to tweak focus and angle of view. Plus it should be rain-proof with the o-ring seal around the dome and under the dome edge.

So there it is, SkyCam_1a 🙂

 

[DaveL59]

ok so with the right lens with IRcut filter, doesn't seem too aflicted by the IR lighting 🙂

thinks the focus will need tweaking tho as I think I've over-reached the infinity focus but wasn't anything useful to fix to with the dull cloudy skies today, but in principle its not too bad. Just missed a bat crossing the camera as I screen grabbed, there's a couple of them that flit around which is nice to see.

So now its just a wait for the wider lenses and the 5MP module...

Edited May 18, 2019 by DaveL59
add second pic

[DaveL59]

ahh I wondered when the kitties would investigate...

I guess the next obstruction will be lookup up a birds behind lol

[MarsG76]

Very nice project... are you having any issues with dew fogging things up?

[DaveL59]

not so far, but then the camera board modules do generate heat and run quite warm, so I guess that'd keep the dome above ambient. Hog cam is exposed direct to atmosphere and never had a problem over winter so hopefully the dome will be the same. Forgot to wipe it over with rain-x when I fitted it so will get around to doing that when I next open it to adjust focus or fit the 5MP board, just to hopefully keep the dome clearer in the rain.

 

[DaveL59]

hmm so as the sky is clearing, the focus might not be soo bad as the v high cloud looks reasonably sharp compared to the dark low clouds when I first fitted this version up. Some flare from the sun hitting the lens plus a reflection off the lens onto the dome but there's not a lot that can be done there - not like I can fit a lens hood on a v wide angle lens under the dome after all 🙂

No doubt the flare and reflection might worsen once the wider 150-180 lenses arrive which may well be later this week as they're in the country already and the 5MP board is imminently departing china on its way here too.

Light rain earlier hasn't affected the rig and so far being toasted by the sun its still working fine too. The black dome structure the module fits to is metal so could be a double-edged sword tho, shunting heat away from the module but also getting hot from direct sun and cooking it. hmmm will have to see how that goes over summer as temps rise...

 

[DaveL59]

hmmm so now is dark and clearer, I can see a couple stars, but as little circles not points, so pretty much confirms focus needs tweaking. Oh well, can wait till the new lenses arrive as it'll be fiddly dismantling atop a ladder and opening up the unit in the dark. I can tho make out ursa major and another bright star, and noted a few planes traverse overhead too

[Gina]

That's not bad considering your equipment   The moon has just risen over yonder hill here.  A lovely deep orange colour.

[DaveL59]

thanks Gina 🙂

For what is in fact a mini CCTV with a 1/2.7-in sensor and a lens that's 15mm across I wasn't expecting planetarium grade images, tho was hoping there'd be a little more. But then the setup is geared at closer objects and day or IR illuminated use really, with the smarts for H264/5+ encoding and motion detection etc sapping power from processing abilities. I don't seriously expect the 5MP will be a big step improvement either, same issues and although a bigger lens its still tiny compared to the C/CS mount lenses or the fab lens you're using, nor a "proper" camera like my Fuji S100FS. The latter I may try piggy-back on the 130EQ2 at some stage when I want to try some imaging as I do have a timer controller so would be able to do long exposure or video and try the lens set from 28-400mm to see how well it copes, the R/A motor on the mount should help it track reasonably well, maybe.

The moon glow has been creeping across the sky here too and now just coming into frame, the sky is full of clouds again, always the way huh.

[DaveL59]

yay so the new lenses arrived 🙂

The 2.1 needs a longer m12 mount and I just CBA to swap that over from the original TVI unit I removed from the dome, but the 1.7 does with a turn or so to spare, I use a locking ring so it ain't gonna shift focus or fall off. Had to pull the boards from the sphere as the lens is wider than the hole but sits lower than the rim, more fun with tiny screws while up the ladder. Still, its in and hopefully focused reasonably well and back on the shed roof once more. Not a bad super-wide view I think tho not the complete image disc as it clips on the longer sensor edges. That's ok as otherwise it'd be catching the upper windows and more of the tree, tho upside would've been getting some view of the small planes going to/from the local airport. Other limiting factor is that with the lens sitting lower than the lip on the sphere it cuts the Fov slightly by a few degrees, not bad tho.

So SkyCam v1b is now up and running, at least for a few days till the 5MP board arrives. Might look at how I can run both the IMX291 & IMX335 cameras alongside each other and be able to directly compare on the same sky views, tho one will be hampered by the dud dummy dome casing. I do think that a M12-1/25-inch nosepiece just might make one of these viable as an eyepiece imager further down the road, via video recording and stacking. IP connectivity not a problem to me in the garden as I can just run a cable out and power it via the LAN cable. Might as well re-use the tech I have sitting around than be buying something else, at least till I decide if this is what I want to do and learn a bit more... 

Edited May 21, 2019 by DaveL59

[Gina]

That's a lot better.

[DaveL59]

yep, more sky and in focus too 🙂

Didn't see the point of tweaking the last setup when I knew the lens would be here a day or so later, figuring the odds that the more often I'm taking it to bits the sooner I'll go drop one of the tiny screws lol

[Gina]

I shall be interested to see the night sky (if you have any left this side of the solstice - just 3 nights left here before we lose astronomical darkness altogether).

Edited May 21, 2019 by Gina

[DaveL59]

yeah kinda the wrong time of year to start this project but once done it'll be there for a good while. Plus so far am able to spend the time, at least till the new job starts in a couple weeks, then it'll be eves and weekends only. So far when the sky has been reasonably clear its still bright till midnight and of course the moon phase does impact what this camera can see. That said, last night it was still seeing stars even as the moon crossed into the view so might even get better views now with the wider lens fitted.

Nice too I can full screen this on the second monitor and almost feel like am out in the open air while at my desk 😄

 

[Gina]

Might get back to my ASC soon.  I tend to swap around with my projects, doing a bit on one then getting tired of it and going on to another.  Guess I have a "grasshopper mind" 😁

[DaveL59]

ahh I'm the same tho, have a couple binos that I'd like to finish fixing up and also to investigate a bit more on what blew on the electronic control on the miele hoover, that got parked as my eyes got too tired looking at micro surface mount stuff. Have another working one to take comparative readings but sort of lost the will a bit on that one. Did flock the objective tubes on the old hensolt dialyt's I've been restoring the other day tho, wow such an improvement to the image when the sun isn't far off axis and a fantastic £15 purchase, one of my favourites in the collection.

Am currently  looking at what's best for the wee Tal-M in terms of repaint, downside of spray will be the "mess" as I've not much space to work in, shed's cluttered but likely the best place to work, tho spray paint in enclosed spaces not so good. Might look at getting the metalwork powder coated instead tho.  Too many projects but I'll catch them all up, eventually, kept me from going stir crazy in the long work gap 😉

 

[Gina]

I've definitely got far too many projects but most are just shelved.

[DaveL59]

well one that is parked for now was looking at making a mold to make up new eyecups for some mini binos I have. Lately was thinking hmmm, 3D printing... not that I have one but they're low price nowadays. Not sure how easy it'd be to knock up a design nor how smooth the finish would be on something that's approx 12-20mm diameter and tapered, one day maybe...

[Gina]

Ah yes, 3D printers, very useful but a whole new "can o' worms" 😁

[DaveL59]

yeah I figure that's likely, one day... maybe, but for that one task those eyecups would be mega pricey where I only need to knock up a couple. Fashion a mold and the sugru or thermoplastic would be way cheaper hence that's a long-term back-burner one