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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.

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** You need every bit of low light sensitivity you can get.

** 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.

** That is terrifying.

....... Phil

Reply to
Phil Allison

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.

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.

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......."

Reply to
rowan194

"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.

** Anyone see a contradiction here??
** Sorry - who was the coward ?

** 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

Reply to
Phil Allison

SNIP

SNIP

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

Reply to
Sally

"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 FUCK OFF BITCH !!

....... Phil

Reply to
Phil Allison

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.

You can only try this and see what happens.

>
Reply to
Terryc

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.

Reply to
rowan194

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

Typical bully, all bark and no bite.

Oh yeah, the intruder was also a bully.

Reply to
rowan194

"rowan194" "Phil Allison" <

** YOU are the one trolling for bullshit info.
** New silly facts - all dreamt up as he goes.

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

You qualify in the former.

...... Phil

Reply to
Phil Allison

I suggest you go have a bex and a lay down philthy , if not then expect another pounding on your security gate button... coward.

Reply to
atec77

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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New concrete makes things even worse. Cheapest fix is to use a filter, and the cheapest filter is the lens out of an old pair of sun glasses. Worked for me for years until I replaced my camera with a decent one.

Don..

--
Don McKenzie

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Don McKenzie

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