DaveL59

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

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...

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

so side by side, and a couple tweaks to the new 5MP AE and it sees a star and so does the 1B version lol Figured out that the "double star" effect in 1B was in fact my IR lighting, so worth considering if you are imaging even with IR filters. The 5MP setup isn't showing it in colour mode but switch to B&W and ugh, not so nice! I have a pair of 4 LED units 6 inc apart at roof level for movement sense on the camera covering the garden and garages, handy to track the kitties and the odd fox or hedgehog. So here you go, piccies, 1B then 2 then 2 B&W and a bit earlier, sunset

ok after a degree of faffing about, the 1B version is back in the small dome and now the 5MP is fitted up in the old dummy dome, side by side on the edge of the shed roof. Still to fiddle a bit with the settings on the new one but its certainly working 🙂 old first and new below. The new one is showing more colour esp to the brickwork but I guess the acid test will be night sky assuming its clear enough.

ack so a minor error on my part. New board module arrived, powers up and gives a nice image. BUT its slightly oversize for the mounting sphere in the mini dome... DOH! So I guess plan-B then, leave this one up and re-fix this new one in the dud dummy dome housing to test and then acquire a new dome for its final fit. Got one on order that I purchased cheap as not working, that's of the larger type with an arm to wall mount it, so hopefully won't be a problem 🙂 So I guess a side-by-side test is on the cards after all lol

yeah I think it may be an insurmountable issue tbh. Thinking back to photography days, losing 1/4 up to 1/2 of a stop is reducing the light entering the sensor plane and in such low light, while you might compensate by increasing exposure time or pushing the ISO (sensitivity) you also gain noise. Also each point of light is now much smaller at the exit pupil (went from FoV 110-180) so per pixel on the sensor there's less light and more dark hitting it, hence you may get brighter stars but not so much the dimer or further stars. I was a little surprised the sky was so dark compared to the 2.8mm lens tho, I'd have expected the background luminescence to have still showed the trees for example. Even switching to CS lenses there's few in the f1.x range and they are mega pricey (350 ish) vs the more available F2.x ones in the £45 bracket. So even with the larger glass you still have the issue of not enough aperture so back to the same situation I expect. In fact the F2.x CS lens isn't that much bigger at the objective than the M12 version, around 30mm so not really much gain for 5x cost. I did have a fiddle with brightness etc and turning on WDR and it lightened things up a little but noise made the image less useful. You could make out a couple stars but pretty much not a very usable image. Still, we'll see with the new board module, one difference with the 5MP sensor that's coming in today is it'll have smaller pixels and similar sensitivity. Not expecting a step back to the earlier setup but it might help a little. Wonder how possible it'd be to hack the on-chip OS to push the shutter speed slower as 1/25 is a lot optimistic for night sky, beyond my skillset tho I'd say, am way too rusty on coding these days and these modules can be easy to brick. Its almost tempting to try a hacked USB webcam, but I doubt the network-USB server would handle streaming video, its fine for scanner and small file transfers but doesn't cope well if you push large sustained transfers at it. Don't really want to put a PC out in the shed as it gets way too warm, plus am not sure about a new neighbour esp after the police have visited several times recently...

ok so while the day view with the new 1.7mm lens was great, the step down from f1.8 to f2 is costly and that loss of light pass means pretty much nothing showing (well, one star low left of centre) where the previous lens showed the tree outlines against the sky as well as some brighter stars, oh well Even the aircraft lights are dimmer than with the faster 2.8mm lens. Will see later how the moon shows but at the mo it does look like a big hurdle, trade off FoV vs faster lens. Also looks like a street light on the far side is reflecting off the lens onto the dome and causing a double "star" pattern, don't think it is the neighbours light in the window but I guess when they turn it off that'll confirm things. A little disappointing then, but of course the stars will be "smaller dots" now that the FoV has expanded so much and that maybe isn't helping either. One option might be to use 2 cameras with 2.8mm lens alongside each other to give a half-half overhead and use a larger dome to house them, hmmmm. Lets see how the 5MP IMX335 starvis+1.7mm plays out then can decide next steps... which could well be tomorrow it seems as its already cleared customs

yep is just the flare on the large front lens element from the sun hitting at a low angle and bouncing internally, looked pretty neat tho, sun setting but outside the actual image area of the lens or was that burning its way thru anodised ally casing to reach the sensor, transparent aluminium is here at last A couple months back I was out for a smoke and there was the crescent moon, but it started as a single at the top and had a double at the bottom. Wasn't able to get a decent pic but I was seriously wondering what was up with my eyes when I first saw it after playing with aligning binos earlier in the day but was the same effect with one or two eyes... @Mars - what's the CS lens you are using tho? I just switched up from 2.8mm to 1.7mm so FoV went fro 100 to 185 degree, tho I'm probably only getting 170 of that since the lens sits just below the edge of the inner module mounting. I did think about going CS for the 5MP module I have coming, for the larger optics, but then there's a jump in price from £7-12 for M12 to £25+ for the equivalent CS and the v small dome case wouldn't have handled the physical size of the CS unit. Oh and they tend to be for larger sensors so hard to get the full view on a smaller 1/2.8 one. Might consider it further down the road if I can sort a housing that would handle it as it'd only be a case of swapping the board lens mount and screwing in the new lens.

ahh looks like the sun has found a way past the edge of the lens as it sets 🙂

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

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...

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 😉