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 🙂

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 🙂

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...

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...
 

1 hour ago, skybadger said:

Ooh, where can I get a 5mp starves from, for that price ?. Sounds like you are the man in the know..

 

Aliexpress 😉

I tend to buy my lenses from Treeye as they tend to be good quality and prompt, and aim for the higher MP lens compared to the sensor in the module as they'd be better quality too, so for the 2MP module I go for 5MP lenses. You can also get the starlight lenses but they don't have IRcut filters, tho they will add those if you ask them. The new lenses I've ordered are for 1/2.5 sensors where this module is 1/2.8 so will see what sort of image I end up with, it may truncate but I am at the experimental stage so...

Thinks I should start my own thread on an el-cheapo sky camera tho so Gina's isn't sidetracked too much 🙂

rather than epoxy as was suggested earlier, some loctite blue threadlock may help? At least you'd be able to undo it later if you needed to tho I can't say the mechanical force acting to rock the pin wouldn't also work it loose over time

so this cctv kinda works, tho stars are faint, pretty much expected given its fighting both the IR lighting and the sky lit by the moon behind the tree...

Can just make out the 3 stars in the tail of the plough at the top 1/3 in from the right, looks better with the mk-1 eyeball but hardly surprising given this module only goes down to 1/25s exposure. Was only expecting to get bright objects with this setup so fairly pleased as it goes, be interesting to see if it does any better in darker conditions but for a v low cost test rig, not a total fail 🙂

thanks Gina, I'm currently playing with the spare kit I have, being between jobs means limiting the spend somewhat so an astro camera is a bit out of reach for now 😉

Here my back yard is not that big and with a large oak tree to SW of where I might put the camera plus houses at around 20-30 degrees above the level a 150 wide would likely do for me at the mo. Will see how it plays, I've ordered a 2.1 and 1.7mm lens so will have a play and see how they go. Might try a 5MP starvis module later on as they can be had for under £20 now, assuming that the current play rig turns out to be viable...

Hi Gina

now wanting to hijack your thread, but this inspired me to get around to picking up the idea I had a long while back but had never got around to it. Since I have a couple spare mini-IP cctv cameras with Sony IMX291 starvis sensors, I bought a dummy dome cctv for a couple £ to test the idea. Fitted up the camera into it and sealed with clear RTV since the clear dome just pushes into the body and fixed it to the pergola by the shed.

Not an ideal setup as its only a 2.8mm M12 starlight lens, needs to be 1.7 I think for this to be workable and focus isn't quite right plus the dome isn't optically great hence the abberations in the image, but... it seems to work so far. One concern I've always had is - do you get the sensor burning out with the sun tracking across it? I do have an IRcut filter behind the lens so hopefully that'll help?

I know I'll have a problem with the security IR lighting so masked the facing edge of the dome to hopefully reduce that a bit, can't move the IR illuminators unfortunately, so will see how hazy the image turns out tonight I guess. If this all works out then I'll look to order in a wider M12 lens and a proper CCTV dome housing (or camera and strip it to retrofit this camera module). 

Nothing as professional as your setup but might be a neat cheapo solution for me 🙂