DaveL59

ok, another dry spell so was able to go adjust things, kinda. Had to swivel Cam1 around as it was obscuring and can still see the base, oh well I can move that later. Canted the 5MP camera on its gimbal so its tilted toward SE, so it should hopefully be able to pick up the moon etc as they transit and hopefully will still see Ursa Maj above. Now just need a clear dark night to see what can be seen. Doesn't have full sky view now compared to the 1.7mm lens before but am hoping the little bit extra aperture will improve what it sees, time will tell... Noticed too that Cam1 had some condensation under the dome. Looks like moisture seeped by the seal under the dome edge where it isn't smooth. Pasted some dielectric grease under the edge after drying it out and will see how that fairs. These CCTV domes really aren't designed to be used upside down but heck they seem to work reasonably well 😄 Left cam1 with the previous lens since the CS ones won't fit into that tiny housing unless I file the lens opening a long way wider. So the new dome (cam2 IMX335) is aimed toward SE and the mini dome (cam1 IMX291) toward EW in terms of widest part of the view which looking at it means it'll catch my IR lighting, such is life.

at least focus looks good 🙂

ugh bleedin british weather! so after lots of rain sky went nice and blue and clear. OK thinks I, ladder out and fit the new dome housing. So just as I'm putting in the camera module sky goes dark and spits of rain. managed to bolt the module base in and just got the dome on before it started heavier, phew! Still need to open it up again tho to adjust the aim and drop a silica gel pack in, plus a dab of silicone around the dome screws. Oh well, its up with the 2.1mm F1.8 CS lens so if it doesn't get drowned I can at least see if there's any improvement 🙂 Had to switch the IRcut trigger too as it was working the wrong way with the CS filter, thankfully the camera module has an option for that 🙂

just don't go with the cheap CCA cables, they ain't Cat anything even tho they claim to be. They do work but exposed to big temp changes they aren't reliable long-term and not so good if you want to use PoE

so true. I recall a few years back when I lived in Essex, the then other half and I drove right out into the country to find a very dark spot so we could watch the meteor shower as we'd not have seen much where we lived by the river, with lights all around to illuminate the walkways.

Welcome Simon 🙂 I'm Kent also, medway area and like you only recently started with telescopes. Am reasonably lucky that I'm pretty much atop a hill and a fair bit of woods around the area, the back garden is fairly dark and not too much light intrusion unless neighbours have their garden lights on. No doubt a darker site would improve the viewing so may look at doing that later down the road too.

hi Pete, yeah getting a lens to give the whole circle isn't easy, the 1.7mm I have clips top and bottom but isn't bad otherwise, except the f2.0 meant a drop in what stars show compared to the previous 2.8mm F1.4 which wasn't bad at all, hence looking for faster. Looks like to get below F2 at 1.7mm means a jump into the £90-200 price bracket tho which I might think about once I've an income again, but I think te ones I've found this far are aimed at larger sensors so may not be worth trying as that'd be a similar result, full screen and losing the full wide view. Just tested the new CS 2.5mm F1.2 and 2.1mm F1.8 indoors on a spare IMX291 camera module, will be a step backward to a more full-chip image rather than the fisheye circular view. When I get a chance I'll pull the 5MP IMX335 module from skycam-2 and rebuild that into a different enclosure with the CS lenses and see if that improves what can be seen. At least then I can have a better idea what's worth spending on regarding a better lens. Agreed they do run warm so with yours having the sensor on a ribbon cable it might be worth increasing the space between the ccd and the rest as the 3516C and similar chips get quite hot on their own. I glued a small heatsink onto the bare board one to shunt some of that away, just superglued direct onto the chip package 🙂 At least the warmth keeps condensation and dew at bay and hopefully will do so during colder months too, the module doubling as a dew heater, maybe. Haven't tried stacking anything from these as yet, with so little being picked up it didn't seem worth the time just yet. Like your image, ursa major is pretty much directly overhead but of late with clouds even on the clearer nights I'm barely seeing more than 2 of its stars where on good nights I might see them all. What I have done on the 5MP was to adjust the max/min shutter speed to the furthest value they'd go to and then set the camera to bias to slow shutter. Does make the sky more washed out (pale rather than deep blue) during the day but that's fine by me.

very nice Pete, is that a USB camera or IP and what speed is the lens, f2? The limitation I have with the IP ones is slowest shutter is around 80ms hence going after as fast a lens as I can reasonably get hold of. Am wondering too how much light pollution you have, looks nicely dark there 🙂

ha and just after I typed that, the next deluge starts, think there's no chance to fiddle out there today. Last year (?) we had torrential rain for several hours along with lightening, the lot. My desk phone died during one set of lightening but thankfully nothing else affected on the equipment front, only the nice 4ft box bush in the garden, which seems to have drowned as it went yellow in the days following and is now totally dead. Can't be certain why the phone was affected but there's a lot of overhead phone cables around here even tho mine's fed below ground. For info I've now got suppressors on the phone, vdsl, satellite and TV feeds and the LAN cable out to the shed, hopefully will limit future damage, worth considering for external cabling if you've not already.

thanks Gina, yeah has eased but it can wait till things dry a bit more or tomorrow I think. Hope you don't get flooding, for sure the weather put paid to plans to go visit a country house with my daughter in my last week or so of freedom, whenever we've both been free its rained lol

oh well, the new CS lenses and IRcut fittings arrived today, took longer than the last order but they're here and now awaiting install. Of course being the UK, weather is against doing anything today, lots of rain. OK is only 12v DC but no way am I going to be messing about up a ladder opening the current casing to extract the electronics from the temp housing and in case folk aren't aware, 12V DC can be dangerous esp if you're wet. So I guess it'll have to wait till the weekend if its dry. Am back to work again from Monday so was hoping to get that in place before but time will tell...

maybe just remove it and measure it off the board, should be close enough...

was kinds thinking something like an old HP server with hot-swap PSU but not sure the 12V would be at the level you're looking for.

I wouldn't recommend doing that James, not without putting some levels of protection in there. You don't want to be back-feeding power from one into the other if there's any drift in output level and potentially introducing instability in the output regulation. Wonder if an option is gutting an old dual-PSU server as some can be picked up pretty cheap, tho they are more geared toward hi-current 5v rather than 12v which would only be driving the fans and drives. If viable then could hang that off a UPS and the DC output side would auto-switch on failure of one PSU or load-share when both are running. But there's still a SPOF - the UPS unless you feed each PSU from a different UPS... ahh the costs will keep creeping up as you aim for resilience. If you do figure on a UPS, the APC's run with 2x 12V or 4x 12v on the 2200 models. So that's £60 per UPS just on batteries unless you have the XL with external batteries too as I have (14 batteries every few years, ouch). Ideally for the UPS side, don't run it at more than 50% load or when you lose mains feed it'll get pretty warm and could shutdown due to internal temp. At say 20% load I can see 1.5 hours runtime on the standard SUA1000's which is pretty decent. Didn't even realise power went a few months back as the desk gear and TV etc just carried on as if nothing had happened 🙂

UPS power will only be smooth if you get a sine-wave output type, a lot of the cheaper ones are a stepped approximation waveform. Might not cause any issues but in the past switch-mode PSU's didn't always get on with the stepped waveforms. You're also sacrificing some efficiency, perhaps but you do then gain surge protection in exchange. If you do decide the UPS route, the APC smartups range are sine-wave output and pretty good buys used on the bay etc, just needing new batteries in the main, just make sure they have the battery cables included. The APC SUA 1400/1500 will need 2x 17Ah batteries but they also have a fan that can be annoying. The APC SUA1000 uses 2x 12Ah batteries but its an easy upgrade to use 17Ah batteries in them. The XL models use the 17Ah ones tho are harder to find used. I've 5 of the 1000's around the house keeping the tech and security stuff powered 🙂

digital display does make things easier, but bear in mind there'll be some volt drop over the length of the cable so the pier end may see a touch less. How much will depend on length and cable type but I see that was covered in your other thread 🙂 Ability to lock the adjust dial would be good too, to save any accidental large voltage changes. Don't forget to fuse the runs at the feed end too, and if you plan on a battery between the PSU and the piers then fuse either side of the battery, better safe esp if any critters decide to enjoy a wee nibble of the insulation for their dessert...

at 13.8v you're feeding the battery a topping charge voltage level or at least on the cusp of that level, not ideal if its already charged and left connected for extended periods I would think. You really need volts set to be in the float charge range so the battery doesn't warm or gas and reduce lifespan. Depending on the battery type the spec range may vary a bit but typically you'd be looking at 2.25-2.27v per cell so more like 13.6v might be better. That's assuming also that temp is in the low-mid 20C range and that you want the battery at max charge level.

UV supposedly kills the growth, assuming the lens and coatings don't absorb it all of course, so periodic exposure can retard or eliminate fungal growth. Needs more than a quick blast though. Expose to daylight for a few hours, or use a UV light for say 30-60 mins as it'll be more a intense closer located source. Storage-wise, several silica gel sachets is always better than one in a larger space, very available to purchase cheaply in different sachet sizes to suit.

well the "new" dome housing arrived, its a used PTZ unit that no longer functions hence a low price. Downside is its a black casing and tinted dome, was hoping the PT part might power and be useable over IP to steer but nada, totally dead. No prob, so I've stripped it down and removed the original boards and cabling, ready for retro-fit of the 5MP module which I'll use the old camera board as a staging mount to bolt the bracket onto. I left the PT motors and wiring in place to keep the camera mount stable, may find a way to use them later but not too important given the camera will be aimed directly upward. Also painted the main body white to try reduce absorbed heat a touch 🙂 So now the wait for a few parts: CS lenses and mounts Clear dome to replace the smoked one Rubber gasket for the dome ring to body seal as there isn't one, so that'd be a problem with this rig mounted inverted I did pop the dome over the existing camera rigs last night just to see the impact, looks to lose 1/2+ stop given the smoked dome not too surprising, tho the 5MP still showed an OK image resolution suffered a little, all cloud so no ability to check against stars, tho aircraft lights showed fine. For sure a smoked dome is no use at all for night use in my intended application. A wee test of my patience now, till all the bits arrive lol

ideally you need to keep some silica gel sachets in with the optics to reduce the moisture levels, and keep them recharged (dried out in a low heat oven) regularly, which may help slow things down. As to killing off the fungus, exposure to UV would work, either exposed to sunlight for a few hours or using UV light source and do that periodically. Other than that you're looking at dismantling the optics and treating with hydrogen peroxide, ammonia, these articles may give some useful guidance: https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3864060/ https://richardhaw.com/2016/03/27/repair-fungus-cleaning/ I guess the problem with astro gear is its rarely getting to see any sunlight/UV and moisture can build as they're moved from cold night environs into warmer after use. Makes having dessicant sachets even more important. Not found a source here in the UK for the sachets shown in the second article, they look very useful to have for optics in longer term storage, was thinking of those for the bino collection but they all have silica gel packs and I try to give each a cycle under UV every couple months just in case.

ahh Starvis is more branding, just means the sensor is more capable in very low lighting, as in more sensitivity. From past equipment the sony exmoor IMX range are a step change from the OV sensors, low light with IR illumination shows well across a wider field where non-starlight sensors fall to dark/shadow earlier. It always helps to have good aperture also, most of my cctv are running with f1.4-2.0 lenses depending where they are covering and the faster lens means the camera can still be showing colour outside even when its quite dim after the sun has gone down. So I thought why not give this a go and point one at the sky, just never quite got around to it until recently. First shot with the 2.8mm wide lens was surprisingly good, that lens is f1.8 or might be f1.4, I can't exactly recall. If it was 1.4 then the step down to f2 would explain a lot as that's a big drop in aperture. Hence I thought I'd swap to CS lenses and test a little further to see if I can improve the view at low cost. The new 5MP IMX335 seems much sharper in image both day and dark night, less noise and better definition to shapes compared to the IMX290/291 so it might give me something workable with the right lens, we'll see. Shutter speed (exposure) is a limiting factor tho since these cctv units generally cannot do much slower than 1/30s since the firmware is more geared to low-blur motion capture than best low-light still image. That said these might be workable as an eyepiece camera with an M12 eyepiece adaptor and feed video clips into stacking software, esp the IMX291 that has larger pixels, a future project maybe.

that's a possible option down the road, perhaps. Never tried the Pi so far as I've a fair few small HP mini desktops and servers cluttering the place and a couple full size desktops that are kicking their heels as spare doorstops. Thing is temps in the shed can get quite high and isn't the most secure so my pref is to not put anything of value out there even tho it is linked to the alarm. I'll play a little further with the cctv setup and maybe revisit depending on the results with CS lenses, just gotta be sensible re £ I think and expectations both with the sensor and the stray light. That said, clear outside rates this location as bortle 5 so there may be limits on what can really be achieved but the earlier results were not bad for such a limited ability setup.

thanks Gina, that's pretty good and 150 deg would do here in many respects given houses are quite close, they don't give the F rating of the lens tho. Downside for my setup is that its USB and that'd mean locating a PC in the shed or perhaps try the USB2 server that I'm pretty sure will barf at the transfer rate or buy a high-end USB server so more expense. I think I will see how this goes with faster lenses and see where this experiment ends up. Gotta slow the spend too, starting the new job in a couple weeks will help there I expect, less time to mull ideas and then just go buying stuff 😉

ok, after a little thinking and scanning the web, decided I'll experiment with the CS lens range. While the current setup does still show a couple stars, literally a couple, it was doing better with the older M12 2.8mm lens that's rated f1.4 or f1.8 in the IMX291 setup. So I have ordered a CS lens mount with IRcut and a CS 2.5mm F1.2 (FoV 130) and a CS 2.1mm F1.8 (FoV 133) which should help to determine what's going to be possible with these IMX291/335 sensors. Assuming the IMX335 performs at F1.8 then I can consider a better CS lens for it later on down the road, IF and when I feel the huge step up on cost might be worth it that is. I notice that getting below 2.1mm in the CS range you get a cost jump to £30-£50 but also aperture drops to F2 unless you want to carry a huge cost step to get to F1.6 (>£200). For my skies and this sensor setup I doubt that expense would be worth it to be honest. Still I should get an idea how far it can be pushed in a week or so. Having 2 cameras set up I can always use one 180 view for total cover and the narrower FoV set up tuned for night sky 🙂

so all in all, hmmmm a minor improvement on the v1B but I think the issue may still be not enough aperture at the lens that's now holding this back more than the sensor. Losing that 1/4-1/2 stop is enough to drop the stars too low perhaps. Min shutter on the 5MP is 1/50 tho you can adjust the max to 80ms (was 63ms) which I have done, no real improvement that I noticed. Setting AGC up to 70 tho improved things a bit more