On Sat, 16 Sep 2023 16:20:53 +0100, Martin Brown
<'''newspam'''@nonad.co.uk> wrote:

>On 15/09/2023 22:37, Jasen Betts wrote:
>> On 2023-09-15, Martin Brown <'''newspam'''@nonad.co.uk> wrote:
>>>
>>> I suspect that on their first appearance in 1963 the eye stalks didn't
>>> glow largely because the special effects had run out of time and money.
>> 
>> a small battery powered lamp, but yeah I guess the line has to be
>> drawn somewhere.
>
>I still remember meeting a Dalek (voice and all) at a BBC event as a 
>young child - they were pretty scary! Not as scary as cybermen though!!
>(cybermen can climb stairs)
>
>I used to have this cartoon on my office wall at university:
>https://twitter.com/PunchBooks/status/1511392231147683844
>
>My office mate had this one but with green snot.
>https://www.pinterest.co.uk/pin/989525349358461609/
>
>I have a friend who had a real ex-BBC Mk I Dalek in his living room!

How does an astronaut scratch her ear?

On 15/09/2023 22:37, Jasen Betts wrote:
> On 2023-09-15, Martin Brown <'''newspam'''@nonad.co.uk> wrote:
>>
>> I suspect that on their first appearance in 1963 the eye stalks didn't
>> glow largely because the special effects had run out of time and money.
> 
> a small battery powered lamp, but yeah I guess the line has to be
> drawn somewhere.

I still remember meeting a Dalek (voice and all) at a BBC event as a 
young child - they were pretty scary! Not as scary as cybermen though!!
(cybermen can climb stairs)

I used to have this cartoon on my office wall at university:
https://twitter.com/PunchBooks/status/1511392231147683844

My office mate had this one but with green snot.
https://www.pinterest.co.uk/pin/989525349358461609/

I have a friend who had a real ex-BBC Mk I Dalek in his living room!

-- 
Martin Brown

On 14/09/2023 08:36, Jasen Betts wrote:
> On 2023-09-12, Don Y <blockedofcourse@foo.invalid> wrote:
>> On 9/12/2023 12:28 AM, Martin Brown wrote:

>>>> Suggestions as to which will give me most *effective* control
>>>> vs. power dissipated?
>>>
>>> Using the least amount of illumination you can get away with.
>>
>> The question is whether that can be obtained by running a bunch
>> of emitters at a low current *or* a fewer number at a higher
>> current.
> 
> Then the answer is YES!
> 
> However current can be varied in more steps than emitter count can.

But you only really need to control a photographic exposure to the 
nearest stop ( power of two in power) or half stop if you are fussy.

Increasingly mobile phones take multiple images at different very short 
exposures centred on nominal 1/4, 1, 4x to create an even higher dynamic 
range - their sensors now are tiny with shallow electron wells.

-- 
Martin Brown

On 14/09/2023 08:46, Jasen Betts wrote:
> On 2023-09-13, 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:
>>>
>>
>> Why do evil robots in movies have eyes that glow? That's bad optics.
> 
> Arthur C. Clarke and Stanley Kubrick started it.
> 
> https://villains.fandom.com/wiki/HAL_9000

I think Terry Nation's Dr Who Daleks ~1964 were amongst the first evil 
robots to have glowing eye stalks but what colour they were is hard to 
say since it was B&W. Here is one rising out of the water under London.

https://en.wikipedia.org/wiki/The_Dalek_Invasion_of_Earth#/media/File:Dalek_Invasion_of_Earth.jpg

I suspect that on their first appearance in 1963 the eye stalks didn't 
glow largely because the special effects had run out of time and money.

-- 
Martin Brown

Carl <carl.ijamesxx@yyverizon.net> wrote:

> On 9/14/23 10:14 PM, John Larkin wrote:
> > On Thu, 14 Sep 2023 21:36:56 +0100, liz@poppyrecords.invalid.invalid
> > (Liz Tuddenham) wrote:
> > 
> >> 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.
> > 
> > I'd love to have a backup cam on my 2008 Audi, but installing the
> > camera and an LCD somewhere sounds nasty.
> > 
> 
> I figured that surely there was a wireless solution these days.  

I considered that --  but as I was partly re-wiring the vehicle to
convert it into a stealth camper, it was more straighforward to just run
the extra cables.  As you  say [below], you still need a power feed.
The only snag was getting the moulded-on connectors through the
'bellows' cable ducts by the hinges of the back doors.  I eventually cut
the cable, threaded it through and soldered it back together again.

> Either find a +12 that's always hot when key is on if you want that, or
> tap into one of the backup light feeds so it only comes on in reverse.

I removed the elaborate radio system and installed the screen in the
space that left in the dashboard, then added a toggle switch alongside
it, so I could switch it on when I needed it.  Sometimes it is helpful
to be able to check what is going on behind the van when parked up.  A
much simpler (but perfectly adequate) car radio is now installed on the
overhead parcel shelf.

There are two cameras, one giving a wide horizontal view and one giving
a downwards view for accurate parking.  I had thought about the
possibility of switching on the LEDs in whichever camera wasn't in use
at the time, so each one became the other's illuminator.  That would
have been done manually when necessary, not automatically at the speed
of light, as suggested by other contributors.  Unfortunately it would
have needed an extra wire and would have meant replacing the wiring
going into the waterproof housings.   I was trying to avoid too much
alteration or any extra risk of water ingress, so decided the extra
benefit (if indeed it was a benefit, because the cameras were so close
together) wasn't worth the risks.

-- 
~ Liz Tuddenham ~
(Remove the ".invalid"s and add ".co.uk" to reply)
www.poppyrecords.co.uk

Martin Brown <'''newspam'''@nonad.co.uk> wrote:

> 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.

Something like FIDO ?   :-)


-- 
~ Liz Tuddenham ~
(Remove the ".invalid"s and add ".co.uk" to reply)
www.poppyrecords.co.uk

On 9/14/23 10:14 PM, John Larkin wrote:
> On Thu, 14 Sep 2023 21:36:56 +0100, liz@poppyrecords.invalid.invalid
> (Liz Tuddenham) wrote:
> 
>> 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.
> 
> I'd love to have a backup cam on my 2008 Audi, but installing the
> camera and an LCD somewhere sounds nasty.
> 

I figured that surely there was a wireless solution these days.  This is 
the first hit I got at Amazon for "wireless car back up camera": 
https://www.amazon.com/Reverse-Vehicle-License-Suitable-Android/dp/B0C1V7VZCX, 
$31.  Camera is on a bar that goes across the top of the license plate, 
uses wi-fi to talk to a smartphone app on iPhone or Android at 1080P. 
Picture shows 3 wires but a couple of reviews say just +12 and ground. 
Either find a +12 that's always hot when key is on if you want that, or 
tap into one of the backup light feeds so it only comes on in reverse. 
Oh, yeah, in honor of the other thread it has built-in IR LEDs :-).

-- 
Regards,
Carl

On Thu, 14 Sep 2023 21:36:56 +0100, liz@poppyrecords.invalid.invalid
(Liz Tuddenham) wrote:

>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.

I'd love to have a backup cam on my 2008 Audi, but installing the
camera and an LCD somewhere sounds nasty.

On 2023-09-13 15:17, John Larkin 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.
 >>>>

 >>>
 >>> 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&rsquo;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?
 >
There's a lidar company called Ouster that has patented the notion of 
running SPADs straight into FPGA inputs, with no TIAs at all.  The idea 
is to improve the time resolution by time-stamping the detection events 
and averaging over a lot of them to smear out the FPGA clock granularity.

Cheers

Phil Hobbs

-- 
Dr Philip C D Hobbs
Principal Consultant
ElectroOptical Innovations LLC / Hobbs ElectroOptics
Optics, Electro-optics, Photonics, Analog Electronics
Briarcliff Manor NY 10510

http://electrooptical.net
http://hobbs-eo.com