John Larkin <jjlarkin@highlandtechnology.com> wrote:> On Wed, 13 Sep 2023 15:35:37 -0000 (UTC), Phil Hobbs > <pcdhSpamMeSenseless@electrooptical.net> wrote: > >> Joe Gwinn <joegwinn@comcast.net> wrote: >>> On Wed, 13 Sep 2023 07:51:50 -0700, John Larkin >>> <jjlarkin@highlandtechnology.com> wrote: >>> >>>> On Wed, 13 Sep 2023 13:57:07 +0100, liz@poppyrecords.invalid.invalid >>>> (Liz Tuddenham) wrote: >>>> >>>>> Don Y <blockedofcourse@foo.invalid> wrote: >>>>> >>>>>> [...] I can afford to move the >>>>>> emitters *out* of the camera (and disable any that are internal) >>>>> >>>>> In my experience that is by far the best thing to do. >>>>> >>>>> Having the emitters inside the camera housing causes reflection off the >>>>> window which reduces the contrast of the scene. If the window 'fogs', >>>>> even slightly, the scene will almost 'white-out'. If the camera is >>>>> outdoors and there is the slightest mist, the light will be reflected by >>>>> the droplets straight back into the camera lens making it unusable. >>>>> >>>>> The illumination needs to come from the sides or above or below -- >>>>> anywhere except directly in line with the camera. Slight shadows will >>>>> also give a 3D effect which helps with recognising people and objects. >>>> >>>> Why do evil robots in movies have eyes that glow? That's bad optics. >>> >>> X-Ray vision? >>> >> >> It’s only bad if it’s unmodulated CW. >> >> Cheers >> >> Phil Hobbs > > I suppose the illuminator could be nanosecond pulsed and the imager > fast-gated. Get some time-of-flight data too. Maybe some advanced > civilization could do that.;) That’s more or less my current project. “Any technology that is distinguishable from magic is insufficiently advanced.”> > But more likely, movies do that to make evil robots look more evil. > Good robots don't have eyes that glow. > >Cheers Phil Hobbs -- Dr Philip C D Hobbs Principal Consultant ElectroOptical Innovations LLC / Hobbs ElectroOptics Optics, Electro-optics, Photonics, Analog Electronics
Ir illuminators
Started by ●September 11, 2023
Reply by ●September 13, 20232023-09-13
Reply by ●September 13, 20232023-09-13
On 9/13/2023 5:57 AM, Liz Tuddenham wrote:> Don Y <blockedofcourse@foo.invalid> wrote: > >> [...] I can afford to move the >> emitters *out* of the camera (and disable any that are internal) > > In my experience that is by far the best thing to do.The downside is that it means making another enclosure for the illuminators.> Having the emitters inside the camera housing causes reflection off the > window which reduces the contrast of the scene. If the window 'fogs', > even slightly, the scene will almost 'white-out'. If the camera is > outdoors and there is the slightest mist, the light will be reflected by > the droplets straight back into the camera lens making it unusable.The cameras I am most likely going to modify have the optics using a (center) portion of the glass shielded from the light of the emitters. There's a cylindrical "condom" that slides around the optical lens *inside* the glass-enclosed case. I am most worried about the power dissipation in the (hermetic) case as I'll be "strobing" the emitters to further reduce power consumption (e.g., overdrive them at a low frame rate by syncing their drive to the video -- "notice" where the light is apparent in the frame and retard/advance until it aligns with the timing of a frame) Once I "see" something of interest, I can increase the rate and decrease the drive as the subject moves into the field of interest (or, leave it at the reduced frame rate/increased range if the subject doesn't approach)> The illumination needs to come from the sides or above or below -- > anywhere except directly in line with the camera. Slight shadows will > also give a 3D effect which helps with recognising people and objects.I have to coordinate the actions of multiple cameras that overlap the scene(s) so will similarly have to synchronize illuminators (when operating at lowered frame rates). (True) recognition is only required "close in" -- e.g., if you approach the front door, I'll have a clearer view of your face/features/size so less reliant on stressing the illuminators (and, more willing to expend power budget as there is a potential for results)
Reply by ●September 13, 20232023-09-13
On 9/13/2023 8:55 AM, Liz Tuddenham wrote:> Why did the reversing cameras in my van come with I.R. illuminators > built-in?Hmmmm... odd, that. The cameras on SWMBO's vehicle are just bare optics, relying on the (LED) brake and backup lights for scene lighting. [And gives me a straightforward way to present live video on that monitor without having to reverse engineer the entire navigation head!]> I had to dismantle the cameras and disconnect the L.E.D.s before they > would work properly in dim light. Now the 21-watt reversing lamp gives > more than enough light for the cameras to work properly, even in fog or > heavy rain.Was this an aftermarket product?
Reply by ●September 13, 20232023-09-13
On Wed, 13 Sep 2023 17:35:38 -0000 (UTC), Phil Hobbs <pcdhSpamMeSenseless@electrooptical.net> wrote:>John Larkin <jjlarkin@highlandtechnology.com> wrote: >> On Wed, 13 Sep 2023 15:35:37 -0000 (UTC), Phil Hobbs >> <pcdhSpamMeSenseless@electrooptical.net> wrote: >> >>> Joe Gwinn <joegwinn@comcast.net> wrote: >>>> On Wed, 13 Sep 2023 07:51:50 -0700, John Larkin >>>> <jjlarkin@highlandtechnology.com> wrote: >>>> >>>>> On Wed, 13 Sep 2023 13:57:07 +0100, liz@poppyrecords.invalid.invalid >>>>> (Liz Tuddenham) wrote: >>>>> >>>>>> Don Y <blockedofcourse@foo.invalid> wrote: >>>>>> >>>>>>> [...] I can afford to move the >>>>>>> emitters *out* of the camera (and disable any that are internal) >>>>>> >>>>>> In my experience that is by far the best thing to do. >>>>>> >>>>>> Having the emitters inside the camera housing causes reflection off the >>>>>> window which reduces the contrast of the scene. If the window 'fogs', >>>>>> even slightly, the scene will almost 'white-out'. If the camera is >>>>>> outdoors and there is the slightest mist, the light will be reflected by >>>>>> the droplets straight back into the camera lens making it unusable. >>>>>> >>>>>> The illumination needs to come from the sides or above or below -- >>>>>> anywhere except directly in line with the camera. Slight shadows will >>>>>> also give a 3D effect which helps with recognising people and objects. >>>>> >>>>> Why do evil robots in movies have eyes that glow? That's bad optics. >>>> >>>> X-Ray vision? >>>> >>> >>> It?s only bad if it?s unmodulated CW. >>> >>> Cheers >>> >>> Phil Hobbs >> >> I suppose the illuminator could be nanosecond pulsed and the imager >> fast-gated. Get some time-of-flight data too. Maybe some advanced >> civilization could do that. > >;) That�s more or less my current project.Single-photon timestamp imagers would be cool, much better than charge integration with occasional readout and dump. But they would create a lot of data. Local processing would help. Where have I heard that idea before?
Reply by ●September 13, 20232023-09-13
On Wed, 13 Sep 2023 12:17:38 -0700, John Larkin <jjlarkin@highlandtechnology.com> wrote:>On Wed, 13 Sep 2023 17:35:38 -0000 (UTC), Phil Hobbs ><pcdhSpamMeSenseless@electrooptical.net> wrote: > >>John Larkin <jjlarkin@highlandtechnology.com> wrote: >>> On Wed, 13 Sep 2023 15:35:37 -0000 (UTC), Phil Hobbs >>> <pcdhSpamMeSenseless@electrooptical.net> wrote: >>> >>>> Joe Gwinn <joegwinn@comcast.net> wrote: >>>>> On Wed, 13 Sep 2023 07:51:50 -0700, John Larkin >>>>> <jjlarkin@highlandtechnology.com> wrote: >>>>> >>>>>> On Wed, 13 Sep 2023 13:57:07 +0100, liz@poppyrecords.invalid.invalid >>>>>> (Liz Tuddenham) wrote: >>>>>> >>>>>>> Don Y <blockedofcourse@foo.invalid> wrote: >>>>>>> >>>>>>>> [...] I can afford to move the >>>>>>>> emitters *out* of the camera (and disable any that are internal) >>>>>>> >>>>>>> In my experience that is by far the best thing to do. >>>>>>> >>>>>>> Having the emitters inside the camera housing causes reflection off the >>>>>>> window which reduces the contrast of the scene. If the window 'fogs', >>>>>>> even slightly, the scene will almost 'white-out'. If the camera is >>>>>>> outdoors and there is the slightest mist, the light will be reflected by >>>>>>> the droplets straight back into the camera lens making it unusable. >>>>>>> >>>>>>> The illumination needs to come from the sides or above or below -- >>>>>>> anywhere except directly in line with the camera. Slight shadows will >>>>>>> also give a 3D effect which helps with recognising people and objects. >>>>>> >>>>>> Why do evil robots in movies have eyes that glow? That's bad optics. >>>>> >>>>> X-Ray vision? >>>>> >>>> >>>> It?s only bad if it?s unmodulated CW. >>>> >>>> Cheers >>>> >>>> Phil Hobbs >>> >>> I suppose the illuminator could be nanosecond pulsed and the imager >>> fast-gated. Get some time-of-flight data too. Maybe some advanced >>> civilization could do that. >> >>;) That�s more or less my current project. > >Single-photon timestamp imagers would be cool, much better than charge >integration with occasional readout and dump. But they would create a >lot of data..<https://en.wikipedia.org/wiki/Ultra-wideband>>Local processing would help. Where have I heard that idea before?Every time XXX-as-a-service was proposed? Joe Gwinn
Reply by ●September 13, 20232023-09-13
Don Y <blockedofcourse@foo.invalid> wrote:> On 9/13/2023 8:55 AM, Liz Tuddenham wrote: > > Why did the reversing cameras in my van come with I.R. illuminators > > built-in? > > Hmmmm... odd, that. The cameras on SWMBO's vehicle are just > bare optics, relying on the (LED) brake and backup lights > for scene lighting. > > [And gives me a straightforward way to present live video > on that monitor without having to reverse engineer the > entire navigation head!] > > > I had to dismantle the cameras and disconnect the L.E.D.s before they > > would work properly in dim light. Now the 21-watt reversing lamp gives > > more than enough light for the cameras to work properly, even in fog or > > heavy rain. > > Was this an aftermarket product?Yes, I installed them myself. I tried to get some without LEDs or with a separate illumination circuit, but they all have the same design fault. You can see them in the picture captioned "Cowl Over Ventilation Holes" at: http://www.poppyrecords.co.uk/Van/vanconversion.htm They are at the top of the back doors near the centre line. -- ~ Liz Tuddenham ~ (Remove the ".invalid"s and add ".co.uk" to reply) www.poppyrecords.co.uk
Reply by ●September 13, 20232023-09-13
On 9/13/2023 1:01 PM, Liz Tuddenham wrote:>> Was this an aftermarket product? > > Yes, I installed them myself. I tried to get some without LEDs or with > a separate illumination circuit, but they all have the same design > fault.Are they marketed as "backup cameras"? Or, as just "generic cameras"? (i.e., in the former case, they should have been able to EXPECT external lighting to be present; in the latter, not) Part of the problem of using an external illuminator is I would need to be able to disable the "internal" ones, yet keep the Ir filter controls (ideally, made external). [I'm looking at large enough quantities that I can probably just design what I want and get someone to build them for me. Silly for folks to put smarts -- CPU, NIC, magnetics, etc. -- in a camera and then not do any real processing beyond "motion detected" (YOU looked at the scene; tell me what *I* want to know!)]> You can see them in the picture captioned "Cowl Over Ventilation Holes" > at: > http://www.poppyrecords.co.uk/Van/vanconversion.htm > They are at the top of the back doors near the centre line.
Reply by ●September 14, 20232023-09-14
Don Y <blockedofcourse@foo.invalid> wrote:> On 9/13/2023 1:01 PM, Liz Tuddenham wrote: > >> Was this an aftermarket product? > > > > Yes, I installed them myself. I tried to get some without LEDs or with > > a separate illumination circuit, but they all have the same design > > fault. > > Are they marketed as "backup cameras"? Or, as just "generic cameras"? > (i.e., in the former case, they should have been able to EXPECT external > lighting to be present; in the latter, not)They were sold as 'Reversing cameras' and came as a kit, with appropriate long multicore cables and in-line connectors to allow them to be installed in a vehicle.> Part of the problem of using an external illuminator is I > would need to be able to disable the "internal" ones, > yet keep the Ir filter controls (ideally, made external). > > [I'm looking at large enough quantities that I can probably just > design what I want and get someone to build them for me. Silly > for folks to put smarts -- CPU, NIC, magnetics, etc. -- in a camera > and then not do any real processing beyond "motion detected" > (YOU looked at the scene; tell me what *I* want to know!)]That's far more complex than anything I have dealt with, but it still needs the basic lighting set-up to be right before embarking on any sort of software or human analysis. -- ~ Liz Tuddenham ~ (Remove the ".invalid"s and add ".co.uk" to reply) www.poppyrecords.co.uk
Reply by ●September 14, 20232023-09-14
On 9/14/2023 1:36 PM, Liz Tuddenham wrote:> Don Y <blockedofcourse@foo.invalid> wrote:>> Are they marketed as "backup cameras"? Or, as just "generic cameras"? >> (i.e., in the former case, they should have been able to EXPECT external >> lighting to be present; in the latter, not) > > They were sold as 'Reversing cameras' and came as a kit, with > appropriate long multicore cables and in-line connectors to allow them > to be installed in a vehicle.So, no excuse for NOT having considered available illumination (and, at least, a way of disabling the internal aspect).>> Part of the problem of using an external illuminator is I >> would need to be able to disable the "internal" ones, >> yet keep the Ir filter controls (ideally, made external). >> >> [I'm looking at large enough quantities that I can probably just >> design what I want and get someone to build them for me. Silly >> for folks to put smarts -- CPU, NIC, magnetics, etc. -- in a camera >> and then not do any real processing beyond "motion detected" >> (YOU looked at the scene; tell me what *I* want to know!)] > > That's far more complex than anything I have dealt with, but it still > needs the basic lighting set-up to be right before embarking on any sort > of software or human analysis.Relying on a generic, COTS solution means you rely on that designer's idea of "right". I have several IP cameras with lots of "smarts"... but, only in the generic sense. They let you statically define a "field of interest" (masking out portions of the scene that are NOT of interest) and will detect "motion" (changes) in those areas. But, won't tell you if it's a person, pet, piece of sagebrush rolling past, etc. The client must then analyze the video to see if it "contains" items of interest. [And, as nothing limits how often motion might be encountered, the client has to be able to process video *continuously*. So, what value to the camera's efforts?] Sort of like the moths (some with wingspans of 6-8 inches!) that flutter in front of neighbor's Nest security light -- causing it to remain illuminated all night long! [How is this any different from an *inexpensive* light that comes on at sundown? What value the CPU *in* that light?] Generic solutions are usually hit-or-miss at solving SPECIFIC problems.
Reply by ●September 14, 20232023-09-14
On 13/09/2023 15:51, John Larkin wrote:> On Wed, 13 Sep 2023 13:57:07 +0100, liz@poppyrecords.invalid.invalid > (Liz Tuddenham) wrote: > >> Don Y <blockedofcourse@foo.invalid> wrote: >> >>> [...] I can afford to move the >>> emitters *out* of the camera (and disable any that are internal) >> >> In my experience that is by far the best thing to do. >> >> Having the emitters inside the camera housing causes reflection off the >> window which reduces the contrast of the scene. If the window 'fogs', >> even slightly, the scene will almost 'white-out'. If the camera is >> outdoors and there is the slightest mist, the light will be reflected by >> the droplets straight back into the camera lens making it unusable.Ideally you want something to cast a rain shadow onto the camera lens or window - something that not all motorway monitoring cameras have.>> >> The illumination needs to come from the sides or above or below -- >> anywhere except directly in line with the camera. Slight shadows will >> also give a 3D effect which helps with recognising people and objects. > > Why do evil robots in movies have eyes that glow? That's bad optics.Its a throwback to the old days of vidicon tubes which actually did glow very slightly in the dark due to the readout electron beam. Baddies and demons usually have red eyes too. (eg I Robot, Planet of the Ood) -- Martin Brown
