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Exposure capture range of a typical B&W analog camera module

I recently purchased a Swann D-CAM which is just a cheap plastic case
in the shape of a security camera with a relatively small CMOS sensor
module sitting at the front. I put the module into a smaller case and
installed it facing out of my front window.

Next day it was obvious that the sunlight was a little too much for
the sensor, it is clearly overexposing (although not horribly). I'm
thinking of sacrificing some night-time sensitivity and SNR by either
placing a filter over the lens, or perhaps some window tint on a small
section of the window glass.

The specs say the shutter range is between 1/60 and 1/15000. Is this
typical for a CMOS module? Would a CCD module fare better in this
regard?

This is just an experiment at the moment, the D-CAM cost all of $29 as
Tricky Dicky are clearing them out. In the long run it would probably
be better to use something with an electro-mechanical iris and the
ability for my computer to control exposure based on the portion of
the frame it wants to expose for (ie, if it's sunny then blow out the
background, I want to see the person's face, not detail of my concrete
driveway!)

Any tips appreciated... my front door was forced by an unknown
intruder while I was standing right behind it.
 
P

Phil Allison

Jan 1, 1970
0
I recently purchased a Swann D-CAM which is just a cheap plastic case
in the shape of a security camera with a relatively small CMOS sensor
module sitting at the front. I put the module into a smaller case and
installed it facing out of my front window.

Next day it was obvious that the sunlight was a little too much for
the sensor, it is clearly overexposing (although not horribly). I'm
thinking of sacrificing some night-time sensitivity and SNR by either
placing a filter over the lens, or perhaps some window tint on a small
section of the window glass.

** You need every bit of low light sensitivity you can get.
This is just an experiment at the moment, the D-CAM cost all of $29 as
Tricky Dicky are clearing them out. In the long run it would probably
be better to use something with an electro-mechanical iris and the
ability for my computer to control exposure based on the portion of
the frame it wants to expose for (ie, if it's sunny then blow out the
background, I want to see the person's face, not detail of my concrete
driveway!)


** It is quite unrealistic to expect to see identifiable faces on a cheap
B&W video camera UNLESS that face just about fills the frame and is close
to square on.

What you are playing about with is total waste of time.

Any tips appreciated... my front door was forced by an unknown
intruder while I was standing right behind it.

** That is terrifying.



........ Phil
 
R

rowan194

Jan 1, 1970
0
** You need every bit of low light sensitivity you can get.

We have a front porch light that's on at night so low light
sensitivity isn't as important. I will also be using a PCI capture
card with frame averaging which will help reduce noise in static areas
of the image.
** It is quite unrealistic to expect to see identifiable faces on a cheap
B&W video camera UNLESS that face just about fills the frame and is close
to square on.

Actually it shows up reasonable quality faces, although the shades
that you would expect are a little off - I'm assuming this is because
the module is IR sensitive and it's picking up more than visible
light.

I was considering a module disguised as a peephole, but the potential
to aim it at anything besides horizontal is probably nil, which means
that it will catch the afternoon sun and could potentially damage it
in the long run. Perhaps there's a module with an iris available which
would work towards solving this issue - general auto-iris until it's
triggered by movement within a specified area, then track and expose
for that moving object.
** That is terrifying.

Yeah, it wasn't much fun. I also happened to be holding a camera in my
hand but didn't manage to fire off a shot. I'm lucky he didn't take
the camera, or become enraged that I had captured his face. A quick
raise of the tyre iron over his shoulder, a couple of lunges at me,
then he was off like a coward.

Next time I'll be making plenty of noise to make it obvious the place
is populated, rather than thinking "who is outside, I'm going to
surprise them and take a photo......."
 
P

Phil Allison

Jan 1, 1970
0
"rowan194"
"Phil Allison"
We have a front porch light that's on at night so low light
sensitivity isn't as important.


** Fraid it still very much is.

I will also be using a PCI capture
card with frame averaging which will help reduce noise in static areas
of the image.


** You just need to get that burglar to stand real still and smile at the
camera.

What's so hard about that ?

Actually it shows up reasonable quality faces, although the shades
that you would expect are a little off - I'm assuming this is because
the module is IR sensitive and it's picking up more than visible
light.


** You are not talking about the same issue I am.

Cos you are too dumb to understand it.


Yeah, it wasn't much fun. I also happened to be holding a camera in my
hand but didn't manage to fire off a shot. I'm lucky he didn't take
the camera, or become enraged that I had captured his face.


** Anyone see a contradiction here??

A quick
raise of the tyre iron over his shoulder, a couple of lunges at me,
then he was off like a coward.


** Sorry - who was the coward ?

Next time I'll be making plenty of noise to make it obvious the place
is populated, rather than thinking "who is outside, I'm going to
surprise them and take a photo......."


** Do something useful - you pathetic wanker.

Like secure you door properly and or add a steel security door.

Have an outside alarm bell you can trigger with a button.

Using a cheap BV&W video camera is useless, or even WORSE than useless.



....... Phil
 
S

Sally

Jan 1, 1970
0
Phil Allison said:
SNIP

Cos you are too dumb to understand it.
SNIP

** Do something useful - you pathetic wanker.

What on earth is wrong with you? Are you completely incapable of having a
normal conversation?
 
P

Phil Allison

Jan 1, 1970
0
"Sally = the anonymous, libelling bitch from Newcastle "
SNIP


What on earth is wrong with you?


** Nothing at all was wrong with my post until some totally * asinine bitch
* SNIPPED it to pieces and entirely removed all meaning. Really pathetic
to do that JUST so you can then post mindless abuse of the author.

Only the very worst scum on usenet pull that stunt.

Are you completely incapable of having a normal conversation?


** Usenet is not some "chat room" for anonymous retards, like Sally -
there are in fact no " conversations " here at all.

Sally is too dumb to have anything to contribute

- so **** OFF BITCH !!




........ Phil
 
T

Terryc

Jan 1, 1970
0
I recently purchased a Swann D-CAM which is just a cheap plastic case
in the shape of a security camera with a relatively small CMOS sensor
module sitting at the front. I put the module into a smaller case and
installed it facing out of my front window.

Next day it was obvious that the sunlight was a little too much for
the sensor, it is clearly overexposing (although not horribly).

Direct sunlight? If so, try moving it so that it isn't exposed, or
install a shade over the spot where the direct sunlight comes from.
I'm
thinking of sacrificing some night-time sensitivity and SNR by either
placing a filter over the lens, or perhaps some window tint on a small
section of the window glass.

You can only try this and see what happens.
 
R

rowan194

Jan 1, 1970
0
Direct sunlight? If so, try moving it so that it isn't exposed, or
install a shade over the spot where the direct sunlight comes from.

It's mainly reflected off the road and driveway surface - there's only
a small amount of sky framed, and that's not the only portion of the
screen that is blowing out. I only have a limited range of movement
with positioning the camera because it's at the top of a window frame
behind glass with decorative crosses, but it *is* located high and
pointing down rather than the reverse.

It would be handy if these things had some sort of rudimentary iris so
you could adjust it to be sensitive to low light (fully open) or
insensitive to bright light (nearly closed)... I guess replacing it
with a pinhole module would have a similar effect to the the latter.
 
R

rowan194

Jan 1, 1970
0
"rowan194"
"Phil Allison"

** You just need to get that burglar to stand real still and smile at the
camera.

What's so hard about that ?

Not sure why I'm bothering to reply to your trolling, but I'll mention
that I'm also considering a prominent flashing LED just below the
camera, so that once the PC detects someone has moved into the
appropriate spot it activates. Person sees the "movement" in their
peripheral vision, then turns to face the source. Snap
** Anyone see a contradiction here??


** Sorry - who was the coward ?

Typical bully, all bark and no bite.

Oh yeah, the intruder was also a bully.
 
P

Phil Allison

Jan 1, 1970
0
"rowan194"
"Phil Allison" <
Not sure why I'm bothering to reply to your trolling,


** YOU are the one trolling for bullshit info.

but I'll mention
that I'm also considering a prominent flashing LED just below the
camera,


** New silly facts - all dreamt up as he goes.


Typical bully, all bark and no bite.

Oh yeah, the intruder was also a bully.


** Only total nut cases ( & guard dogs) deliberately confront intruders.

You qualify in the former.



....... Phil
 
"rowan194"
"Phil Allison"



** Fraid it still very much is.


** You just need to get that burglar to stand real still and smile at the
camera.

What's so hard about that ?





** You are not talking about the same issue I am.

Cos you are too dumb to understand it.

Explain it then fag boy , should I allert Roddles to your post ?
I expect most of the group don't care what you post but some might
and will be suitably amused at your sillyness
** Anyone see a contradiction here??

about you certainly , take more meds fagboy and do try to make some
rational with out being a putz
** Sorry - who was the coward ?

you the last time someone called , perhaps when next you meet meet
fagboy might open the security gate ?
** Do something useful - you pathetic wanker.

speaking of wanker have you felated anyone of late philthy ?
Like secure you door properly and or add a steel security door.

Have an outside alarm bell you can trigger with a button.

Using a cheap BV&W video camera is useless, or even WORSE than useless.

wrong again philthy , it is not a solution but a learning process
 
"Sally = the anonymous, libelling bitch from Newcastle "





** Nothing at all was wrong with my post until some totally * asinine bitch
* SNIPPED it to pieces and entirely removed all meaning. Really pathetic
to do that JUST so you can then post mindless abuse of the author.

Only the very worst scum on usenet pull that stunt.


** Usenet is not some "chat room" for anonymous retards, like Sally -
there are in fact no " conversations " here at all.

Sally is too dumb to have anything to contribute

- so

....... Phil

I suggest you go have a bex and a lay down philthy , if not then
expect another pounding on your security gate button... coward.
 
I've found a CCD module with a 1/50 to 1/100,000 shutter speed range.
It's capturing a fully sunlit street at the moment and there is no
large scale overexposure like with the CMOS module - the only obvious
point is the sun on a white verandah post. The dynamic range seems to
be greater also, the output is of lower and more even contrast rather
than being harshly clipped at the dark and bright ends.

Most importantly, you can clearly make out facial features in this
brightly lit situation.
 
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