Low light CCTV?

[Andrew May]

You could try one of these:

[alan_m]

Few, large surface area pixels. Not something that could fit in a mobile phone

[Bill Wright]

Yes. That picture was taken from just such a camera, and it wasn't set at anything like the lowest light level.

Bill

[T i m]

On Wed, 20 Nov 2019 14:47:44 +0000 (GMT), "Dave Liquorice" [e-mail] wrote: <snip>

Clever aren't we, how we have evolved such things. ;-)

I've had experience of that going a bit wrong when I had what I think they described as some 'wet' distortion of the macular in one eye making square things look distorted and creating what looked like a oil stain on anything I was reading (that wouldn't wipe off and moved when I looked elsewhere). ;-)

Luckily, it cleared up on it's own and if it hadn't, any (laser?) surgery I could have had on it would have left permanent distortion (in my main focal function in that eye).

Cool. ;-)

It's this sort of 'human' thing I was talking about in another group regarding the proliferation of what many of us would describe as 'overbright' vehicle headlights.

In the old days, the light levels projected and visible were directly related to the wattage of the lamps used and hence the wattage limit / restrictions. Yes, upgrading your headlamp bulbs to something more powerful might make things better for you but not anyone else (especially those swept by them on corners and on roundabouts etc, even if they were properly aligned / focused).

Eg, we (humans) have a tolerance to a range of light levels, from pretty dark to a bright sunny day and we can generally cope with them all (by looking away from the sun etc) but we don't generally have the same option when driving.

And it's not just the light levels, but the colour temperature and density of a source that can make a big difference as well (LED / laser V an incandescent filament). You get bright lights at a football match for example but they aren't painful to look at.

Cheers T i m

[whisky-dave]

It's not for a mobile phone it's to help T i m get the CCTV night vision system he wants. I assume he has soem sort of spending limit or budget and at a guess I;m betting that the above camera (he may require more than one too) might exceed this.

[T i m]

Cool.

So, if you set it to a sensitivity where it wouldn't smear with (say) someone walking across the scene, would it be any more sensitive than a cheaper camera with an inferior light level spec would you think?

Or is it that these cameras are still good vfm no matter what you are aiming for?

Cheers, T i m

[whisky-dave]

Are they that bright though ? I've not been to a football match and I;ve only seen them from a distance. But teh shodows don;t seem as dark as those that the sun produces, but then again those lights come from at least 4 differnt directions. Your eyes do adapt over time to differnt light levels.

Think of those kids in the cave in thialand and how they had to wear eye protection when they came out. Aslo mots can;t tell the colour of a star from just veiwing with the naked eye. but they aren't all white. I can just make out that Mars has a sort of orange colour.

[Dave Liquorice]

football

These days at many Premier League stadiums each luminaire is about 2 kW LED and there are around 100 of 'em. They are no longer up stantions in each corner but encircle the pitch mounted above/blew the stand rooves. The light level, evenness and shadows (the playing area is almost shadow free) are very tightly specified. Premier League and Champions League have slightly different specs both can be found on the 'net.

Mostly down to the light level from the point source of a star not being high enough for the cones to work. You can tell the colour of the really bright stars. Mars isn't a star. B-) and looks like a red/orange dot to me, Jupiter is a definate disc.

[Bill Wright]

I'd guess so. Of course you can use a wide aperture lens with these cameras if you like. However I think they are discontinued! The last one I bought had an integral lens. The low light performance seemed just as good though.

Bill

[Martin Brown]

Jupiter might seem like a disk to you but it is more likely to be from scattering in your eye. A tiny handful of young children with better than 40:20 vision can sometimes see the Galilean satellites of Jupiter in the most favourable conditions (and also split epsilon Lyra).

Mars is very obviously red/orange. Saturn is yellowish. Venus is pure white very bright. Visible in daylight at maximum elongation if you know exactly where and how to look.

Arcturus and Betelgeuse are also orange. Rigel is bluish white.

First and second magnitude stars do show some colour to the naked eye but it is hard to judge unless you compare one with another. The human eye is rather good at doing an automatic white balance.

The brightest stars Sirius and Canopus when they are low in the sky appear to flicker between quite saturated colours due to wavelength dependent differential refraction.

[T i m]

And that was my caution, re spending a substantial sum on something where I don't fully use it's USP because of some compromise (smearing) and where it's use may not be ideal (for said USP).

eg, Say you needed to see what order a range of different colour cars parked each night (with no additional light), or to determine what pattern / colour cat is stopping for a dump on your vegetable patch ... a NiteDevil set on it's most sensitive might be a good way to go. ;-)

Again, from my small exposure to camera lenses (excuse the pun), aren't bigger aperture lenses often more expensive?

Doh!

If we are still talking Nitedevils I think I saw those as being 'indoor' cameras for nightclubs and pubs etc.

It sounds like what am looking for could be the holy grail of CCTV cameras and unless finding something second hand, might just be something you have to pay for.

I was hoping to find something (with practical recommendation) that would offer as good a resolution as my DVR could use, give quality colour pictures in as low a light as possible (/ reasonable), be reliable (electrically and in use) and ideally, considered good VFM by most.

The other thing I believe I sound consider is the lens. eg, without having mechanical zoom (likely to make it more expensive and once set, likely not to be ever changed) or any PTZ features at all (see above), I need to determine what 'angle' of lens would give me the sort of width I want to cover at the distance I'm interested.

eg. If it's under the eaves on the rear wall of a house overlooking a back garden, I would want it to cover the length of the garden (so that would be the 'vertical angle') and the width of the garden (the std way we normally consider 'wide angle' etc) but no more than necessary (to retain more 'focus' on the desired area.

Like a floodlamp, I would set the upper edge to just capture the bottom of the garden and the lower edge would then be wherever it was (ideally, near the back of the house).

However, I'm guessing whilst the lenses are generally round, the CCD's aren't(?) and so I'm guessing there must be some overlap / compromise between the size of the image projected onto the CCD and what you see from the CCD?

For my scenario above, maybe I need a widescreen rotated though 90 Deg to best fit my target area? No use if I have other cameras that use a more traditional layout of course. ;-(

Cheers, T i m

[whisky-dave]

My local football team is Leyton Orient which might explain why I've not noticed.

Difficult in London unless you're in a dark place for a while.

I k ow but even the clever greeks called them wandering stars, and stars are brighter in reality but so far away and such a small 'footprint' that we can't easily tell the colour, which was my point.

[whisky-dave]

It's important to use logic and science here rather than ceativity/emotion. I'm sure you must have seen the effect sodium street lights have on your perception of the colour of parked cars. So what you see as colours (which don't really exist) is dependant on the colour of the light shone on the cars and what colour(s) they reflect. No light no colour, even if you have a colour amplifier which goes up to 11.

Now we see the real reason :)

Yes, due to the extra glass or plastic required for the elements and everything that goes with with it.

They do out door ones but I'm guessing they are far more expensive that is what I foubd when looking for an outdoor web cam. The price seemd to triple or more.

Yes and they still can't do the impossible.

We can all hope.

That is also coupled to the sensor size of the camera, in photography it;s called the crop factor, but you could get some idea of the angle of wiew using a simple protractor and a couple of matchsticks. I;d ask someone with a reasonable camera and lens and ask them to take some pictures and then see what the focal lengh of the lens was at and hence find the angle of view.

Yopou'd need a good zoom in order to take pictures of the cat taking a shit for ID purposes I doubt the ECHR will proceed with a low quality picture of the cat. :-}

Standad practice for all cameras, lenses and CCD excapt perhaps the hubble and the like.

[alan_m]

Mine was more of a comment about modern mobile phones being capable in low light conditions. The individual pixel area in these cameras is possibly 100x more than that in a phone camera yet Canon have to go to this extreme to produce a quality image via candlelight.

[whisky-dave]

Yes they are and modern camera can also good zooms and closeup facilities.

But DLSRs and smartphones aren't used as CCTV.

Yes so. Find a CCTV system that makes use of iphones or pixels or any other smartphone or DLSR or any camera how about those go-pros set up a CCTV system with those. Or invent one yourself.

[T i m]

<snip>

<snip>

Idiot. Squirm your way out of these then ...

Cheers, T i m

[whisky-dave]

if that's what you want go for it, I doubt it'll do what you are expecting at the price you're willing to pay.

yes I can see the 4 or so iphone11 around your property being a solutionb so why are you asking for advice if yuo already knew how to do it.,

what do they say about the low light feature that you want. ?