Some Clarity On IR Cut Filter...PLEASE

[emholic 0]

Hey guys,

 

I've been under the impression that an IR CUT Filter is supposed to give you the best night time picture because of the physical filter for the day/night function as opposed to a digital day/night function.

 

what am I missing?

 

I'm going based off of a camera I installed which offers

 

Sony HQ1 DSP

Mechanical IR Cut Filter

min Lux .15 << not sure why the lux is so high.

 

I'm getting a disgusting image at dusk and when in B/W mode its blurry.

 

Obviously I'm changing the camera out BUT... what IR CUT Filter??

 

Thanks!

[rory 0]

That doesnt sound right, whats the camera model?

The ICR itself though wont make the camera a low light camera, it just puts a filter in front of the camera in the color mode to block out Infrared so you dont get glare and washed out colors, and removes the filter in BW mode so the camera can see IR light. The camera itself and moreso the chip has to do the rest of the work. By removing the filter it can also be more sensitive, but still the chip itself has to be capable.

[emholic 0]

OK, so the IR Cut Filter has nothing to do with B/W mode?

 

WDR cams are used for facing doorways or windows and what not.

 

Can you give me an instance of when this type of camera, IR Cut, should be used?

[cglaeser 0]

Can you give me an instance of when this type of camera, IR Cut, should be used?

 

Color sensors work best in the visible spectrum. Infrared can compromise the quality of the image. So, to eliminate the infrared, manufacturers add an infrared filter in front of the sensor. Day/night cameras typically have a BW mode for low-light performance. However, at night in BW mode, the sensors need all the light possible, including any ambient IR and/or added IR. So, the filter is removed so the sensor can collect both visible and IR. The IR cut filter is typically added/removed electronically when the camera switches between day/color and night/BW modes.

 

Best,

Christopher

[emholic 0]

Hey Chris,

 

Thanks for the reply.

 

Visible Spectrum = Light

 

IR = Glare

 

Glare = Bad

 

IR Cut Filter = Stops Bad

 

Stopping Bad = Good Picture

 

Good Picture = Happy

 

Thanks,

 

Nick

[rory 0]

OK, so the IR Cut Filter has nothing to do with B/W mode?

 

WDR cams are used for facing doorways or windows and what not.

 

Can you give me an instance of when this type of camera, IR Cut, should be used?

 

You can buy an IR cut filter separately, its just a filter that is placed in front of the camera. It does nothing but filter, in this case, block Infrared. With True Day Night Cameras, the camera has a mechanism that slides the IR Cut Filter back and forth. If you want a decent day and night image from a single camera, then it is recommended to use a True Day Night camera, over the basic Color IR camera - unless one can afford a dual day night camera (2 separate cameras in one).

 

Mechanical ICR puts the price up, which is why the True Day Night cameras cost more then the color IR cameras. They normally use slightly better chips in the True Day Night cameras also. But its all about cost, you get what you pay for.

[rory 0]

Hey Chris,

 

Thanks for the reply.

 

Visible Spectrum = Light

 

IR = Glare

 

Glare = Bad

 

IR Cut Filter = Stops Bad

 

Stopping Bad = Good Picture

 

Good Picture = Happy

 

Thanks,

 

Nick

 

Im not sure what your question is here, but ICR does not remove glare.

[emholic 0]

Got it.

 

Not to drag this on, but regarding Digital D/N, it's just an internal component switching modes correct?

[rory 0]

digital DN would just be the camera removing the chroma (color) and making other digital adjustments. Typically there wont be any ICR at all.

[emholic 0]

Hey Chris,

 

Thanks for the reply.

 

Visible Spectrum = Light

 

IR = Glare

 

Glare = Bad

 

IR Cut Filter = Stops Bad

 

Stopping Bad = Good Picture

 

Good Picture = Happy

 

Thanks,

 

Nick

 

Im not sure what your question is here, but ICR does not remove glare.

 

When I hear you guys talk about Infrared during the day, I assume the sun. The only issue I can see with the sun might be glare or something of that sort.

[emholic 0]

OK got it, thanks for your help I really do appreciate it!

[rory 0]

 

When I hear you guys talk about Infrared during the day, I assume the sun. The only issue I can see with the sun might be glare or something of that sort.

There is plenty IR when the sun is out, you will see it mostly on things like bushes, grass, etc. So unless it is cloudy 100% of the time, you will notice the washed out colors from the Infrared, however, some cameras (not the cheap ones) now do a very good job of digitally enhancing the colors.

[cglaeser 0]

Hey Chris,

 

Thanks for the reply.

 

Visible Spectrum = Light

 

IR = Glare

 

Actually, both are light, just different frequency ranges. We can see in the range blue to green to red, and then our ability to see light falls off just beyond the red, called infrared. Many sensors can see both the visible spectrum and infrared spectrum. Filters are typically used to create a color image. A Bayer filter is used to separate the blue, green, and red channels, and an IR filter is used to enhance the color image by removing the infrared. In the daytime, there is plenty of light, so they can afford to filter the IR. At night, sensors need all the light they can get, so they remove the IR filter and use both the visible spectrum and the IR spectrum.

 

Best,

Christopher

[emholic 0]

Hey Chris,

 

Thanks for the reply.

 

Visible Spectrum = Light

 

IR = Glare

 

Actually, both are light, just different frequency ranges. We can see in the range blue to green to red, and then our ability to see light falls off just beyond the red, called infrared. Many sensors can see both the visible spectrum and infrared spectrum. Filters are typically used to create a color image. A Bayer filter is used to separate the blue, green, and red channels, and an IR filter is used to enhance the color image by removing the infrared. In the daytime, there is plenty of light, so they can afford to filter the IR. At night, sensors need all the light they can get, so they remove the IR filter and use both the visible spectrum and the IR spectrum.

 

Best,

Christopher

 

 

I now understand that with an IR Cut Filter Camera that the Filter makes the camera "a COLOR camera." Without the Filter, the camera is B/W.

 

Rory, when you say digitally enhancing the colors, are you saying there is a digital enhancer with an IR Cut Filter?

[rory 0]

No No .. the ICR does nothing to the camera .. it just blocks the IR!

[cglaeser 0]

Rory, when you say digitally enhancing the colors, ...

 

Digital enhancements are done in the processor, sometimes called post processing. Contrast, saturation, gain, and sharpening are a few of the features typically done in post.

 

Best,

Christopher

 

Edit: Filters are designed to block certain wavelengths of light from reaching the sensor.