Surveillance Camera Imager Tutorial

Author: IPVM Team, Published on Dec 23, 2016

Imagers - CCD, CMOS, 1/2", 1/4", big pixels, small pixels, etc.

In this tutorial, we explain the fundamental issues and drivers in surveillance camera imagers, including:

  • Sensor vs Imager
  • CCD vs CMOS
  • Imager Manufacturers
  • Camera Manufacturer Imager Disclosure
  • Imager vs Resolution
  • Imager Size
  • Pixel Size
  • Imager vs FoV Width
  • Imager vs Low Light Performance

Plus, we provide a 7 question quiz at the end to test your knowledge.

imager free image4

******* - ***, ****, */*", */*", *** ******, ***** ******, etc.

** **** ********, ** ******* *** *********** ****** *** ******* in ************ ****** *******, *********:

  • ****** ** ******
  • *** ** ****
  • ****** *************
  • ****** ************ ****** **********
  • ****** ** **********
  • ****** ****
  • ***** ****
  • ****** ** *** *****
  • ****** ** *** ***** ***********

****, ** ******* * * ******** **** ** *** *** to **** **** *********.

imager free image4

[***************]

Sensor ** ******

******** ****** ************* **** ***** ********** '******' ** '******'. **** referring ** ************ *******, **** **** *** **** *****, ******, technically, ** ****** ** * ******** **** ** ******. ******* of ****, ** **** ********* ***** ** '******' **** ******** about ************ *******.

CCD ** ****

*** *** **** ********** ***** ** ******* **** **** *** and ****.

*****, ** ****, ********* *** ************ ******* *** ****, **** the **** '****' ** *** '*****'. **** ** *** ******** of * ****** ***, **** *** ******* **** *********** *** CMOS *** ****** **** **** ** * ***** ****, ***** quality ***********.

******* *** **** *** ******, * ********* ******* ******* ****. However, **** ** *****, ********** ***, ** * ********* ******, impossible. ** *** **** ****** *** *******, *** ***** ********* almost *** ****** ************ *******, ********* *** '***' ****** *** models.

**** **** ***** *** *****

Imager *************

***** *** **** * *** *********** ************* ** ************ *******, with *** **** ********** ***** *******************,********* ****. **** ****** *************, ****** ************* ***** * ***** of ****** **** ******* ****, *** **********, ***** **** *** WDR ************, ** **** * ***.

Camera ************ ****** **********

****** ************* ***************** ****** ************ / ****** **** ***, ** ** ** not **** ** ******* *** ******* ***** ** ***** *******. Some **** **** *** ****** ************ *** *** *** ******** model. *** *******, **** ** *** **** ** *** ************, ********** ***** ****** ** ******* **** ******* ***** / performance *********. ********, **** ** *** **** * ******* **** using *** ***** **** ****** (***** ** ****, ** ********), differences ** ******, ******** *** *********** ***** ***** ****** ** noticeable ******* ***********.

Imager ** **********

******* **** ** *** ******* ********** **** *******. **** ********** the ******'* ******* **********. **** ******* *** *** ** ***, 1.3MP, ***, ***, ***. ********, ** / **** ******* **** emerged ***** ** ******* ** ****** ** *******.

Imager ****

******* *** ***** **** ********* ***** (*.*., *****) ** ********* small (*.*., **** ******). ************ ****** ******* **** ** **** in *** ******, ******, *** ********* ******, **** **** ***** imagers.

*** ***** ***** ***** *********** ****** ****. *** *** ****** cameras ** *** **** *** ****** *** ******** *** ************, while *** *** ** *** ***** (*/*.*") ** ******** ***** fairly ***** *** ******* ************ *******, *** **** **** ******* to *******:

imager size comparison

** ************, **% ** ******* **** ******* **** *** ******* 1/2" *** */*". *** **** ****** ****** **** ** ************ is ~*/*", **** */*.*" *** */*.*" **** ******. **********, ***** resolution ****** (****/*.*** *** *****) ***** **** ******* */*" *******, but **** ***** ****** ************* *** */*" ******* *****.

********** ****** ****

**** *** **** *** *****, *** ******* ****** **** *** increased **********. ** *********** ******** ** ***, ***, **, ***., imager ***** ****** **** */*" *** ********** ******** **** ******.

Rise ** */*"+ *******

*** **** ********* ***** ** ****** **** ** *** **** of */*" ******* ** *** **** *** *****. **** ************* now **** ** ***** *** "**** ***" ***** ***** ***** a ~*/*" (** */*.*", */*.*", ***.) ******, ******** *** ***** low *****.

************, ****** ********** *-*** ****** ***** */*" ** ******** ****** imagers *** *** ********** ******, ********* ** *************' ****** *********** models, **** ******' ** ***** *** *** *****, **** */*.*",****** *** ***-*****(*/*.*"), *********** *** **-*********-****(*/*.*").

Much ****** **** */*" ***** ****

******* ****** **** **** ****** **** */*" *** ***** **** rare ** ************, **** **** * ******* ** *******.********'* ********* ** **** ***** *** ***** *** ** ***** ******* (27.2mm/~1.07"), *** ****** **** **** ******** ** ****, **** ******'* **** *****,**** *****, *******'* ***** */* *****.

Imager **** **********

****** ****** ************, ****** **** ** ****** ****** ********* ** camera ************* ** ************* ******. **** ** ** ******* ** the ***** ** ****** ********* ********:

Pixel ****

******* **** ** *** **** ** ***** ******, ******** ** microns.

***** **** ** **** ******** ********** ** ****** **** *** number ** ****** (*.*., **********). *** ****** *** ******, ********** else *****, *** ****** *** ***** ****. *******, ** *** add **** ****** (*.*., ***** **** ** ** **) *** the ****** **** ***** *** ****, *** ***** **** *********.

****'* ** ******* **** ** ****** ************* ******* ****** ****, resolution *** ***** **** **** ** ****:

**** ****** ****** ***** ***** *******, ********** **** *****, * larger ***** *** ******* **** *****, *** ********* ******* ******** / ****** *** ***** ******. *******, **** ***** ******* ****** low ***** *********** ** ** ** *** ****** / **** to ******** *** ****** ** ****** **** ******* ***** ** pixel ****.

****, ***** **** ** ****** ***** ********* ** ****** *************, so *** **** *** *** ** ** ******** ** ******* at *** ********** *** ****** **** ** **** *****.

4K ******* ********* ******* ***** ****

** ******* *** ************ ******. ******** **** **** ~** *** pixels ** ***** ******* *** ** ****** ******* *** ********* larger **** *****, ********* *** ***** **** *** ** ******* is *******. **** *** **** *** ***** ***********. ****, ** we ******* *******, ****** ** ***** ********** **** **** ** cameras.

**** **** **** ** *** ****** *** ****, ******* ** super ***** ****** ****** **** ** ***** ** ****'* **** models, ****' ***-* *****, ***., ***** *** ****** ****** **** increases ***** **** ***************.

Imager **** ** *** *****

****** **** *** * ****** ****** ** ***** ** **** and*** *****. *** ******* *********** ** *** ** **** ****** (*.*., 3mm, ****, ****, ***.).

*******, *** ****** *** ******, ********** **** *****, *** ***** the ***** ** ****.

** *** ***** ****, ****** ***** ** ************ ** *** vary **** ****, ** **** **** ******* ********* ****** *****, the *** **** ******* **********. *** *******:

larger imager size wider angle of view

** ****, ** ********* ** *** * ***** *******, *** is ***** ***** ***** **.

Imager ** ******

******* **** ******* ** ** **** *********** ***** (*.*., *.***,*****, ***.). ******* *** ********* ****** ***** ******* ** **** they ******* *** *** ****** ***** *** ***** ************ ** the ** ******* / ****** ** **** (***) ** ******* this.

Imager ** *** ***** ***********

******* *** ** ****, *** *********, *** **** ******, ****** in ******* ** **** ****** ******* ****** ******* ****** *** light ***********. ****** ****** ******* ****, ***** *** ***** *** drivers **** ********* *** **** *********, ****** *** ***** ***** processing **** ** **** ** *** ******* / *** ** the ******. **** *** ***** **** ** ********* **** ** *** ***** *********** *****.

*******, *** ***** */*" ***** ****************** *** *** ******** ********* ****** **** *** *** */*" ***** *******, ** these ****** ********* ***** *** **** (** ******) ********** **** in */*" ****** ** ****** */*" ******* **** ****** ***********, resulting ** ******* ****** ***********. *** *** ***** ******' */*" ***** ******,***** ********* */*" ******,********* ***********, ********** */*" ******* *** ********* ********.

************, ***** *** * ****** ** */*" ****** ******* ********* lacking ***** ********** **** *** ***** **** ** *** *****. Also, * ****** ** ** ******* **** */*" ******* ** larger, *** *** ***** *** ** *** ***** ******* *** pixel **** ** ****** ***** *** *** ******* **** ** lack *** ********** ***** ** ******* **** ***** ***********.

Quiz ********

**** *** * ******** **** *** *** *** **** *** know *******.

Updated ****

**** **** *** ********** ******** ** **** *** *** ******* in **** *** **** ** ******* ************ ** */*" *** larger ******* ** **** ** *********** ** ** *******.

Comments (9)

Hi, I want to share the following information; as far as I know, increasing the pixel size will decrease the spatial resolution. I'm quoting form the following link "Images having higher spatial resolution are composed with a greater number of pixels than those of lower spatial resolution"

http://micro.magnet.fsu.edu/primer/java/digitalimaging/processing/spatialresolution/

"increasing the pixel size will decrease the spatial resolution"

That's true, assuming the imager size stays the same, simply because the total area is constant but the size of the components (i.e., pixels) have expanded. Bigger pixels in the same space means fewer total pixels, i.e., spatial resolution.

Btw, this is a tautology:

"Images having higher spatial resolution are composed with a greater number of pixels than those of lower spatial resolution"

This is true, by the definition of spatial resolution. However, it does not mean it has better image quality - Pixels Determine Potential, Not Quality

In surveillance, 95% of cameras have imagers that are between 1/2" and 1/4". The most common imager size in surveillance is 1/3".

Is that the horizontal size or diagonal size, or area?

The imager size is convention, not an actual measurement.

From the wikpedia page on image sensor format:

"Sensor formats of digital cameras are mostly expressed in the non-standardized "inch" system as approximately 1.5 times the length of the diagonal of the sensor. "

For example, a 1/4" imager has a diameter of 4mm (or .157 inches). Multiplied by 1.5 gives nearly 1/4".

Here's an excerpt from the wikipedia table on imager size dimensions:

So it's kinda like a shared fairy tale that all the manufacturers tell round the campfire? Who gets stuck holding the "short end" of the stick?

At the risk of being pesky, there is a mighty odd thing going on there in that thar chart, where whenever the inch size denominator is an integer, the diagonal measurement is an integer too, but in mm. I can't think of how the heck that could happen except by chance?

One more for the road, does that mean that a 1/4" sensor is will always be having the same aspect ratio, or is that chart just a one example of what it could be? Thanks for the lesson.

Jim, I'm a little surprised at your surprise; after all you were the first person to answer a similar question correctly, (though looking back, you did say you "cheated" :)

I never really found a satisfactory answer to how it came to be, but I don't think it's to 'hoodwink' anybody. What I did learn was that 'back in the day' , way before IP cams, the CCD sensor was surrounded by some kind of vacuum tube (help tube expert!) thingy that made the diagonal size of the whole component "1/4 or whatever. But of course the active sensor size was smaller. Then they stopped using the tubes, and started making smaller packages, just because they could.

My guess us when that started, they had to agree on the active dimensions of the old packages, and for some reason (help, fab expert), did that in mm. And that married the even inches to the even mm. Maybe John or somebody knows more. But its just history that's unimportant now, and like Brian basically said the only thing you need to know is you is that you don't know the exact size by the fractional inch thing, its just a convention.

****Quiz Spoiler alert****

Pixel size is the best metric to gauge low light performance.

Objection: the explanation to the answer does not give us any better metric than pixel size, saying

Pixel size is rarely disclosed, so it is hard to use as a metric. One can estimate it by contrasting resolution and imager size.

But since resolution and imager size are almost always present, one can almost always derive it thru simple division. Or add the calculation to the camera calculator, it's as easy as PPF.

However, even with that, low light quality varies greatly depending on image processing

Image processing is not a metric.

and integrated IR usage.

Most cameras, according to the finder, do not have IR, and therefore this might be hard to use as a metric.

Also, strictly speaking IR removes the low-light condition by adding (IR) light. In the case of the (few) cameras with integrated visible light, we would probably not say it had 'good low-light performance', rather we would say it had a 'good light'.

Did you have another metric that is better than pixel size?

On the other hand, imager sizes in surveillance do not vary that much, so even with notably different imager sizes, the FoV only changes moderately.

Just to note, the change in FoV width is directly proportional to the change in sensor width, and inversely to focal length. In the example, a 1/3 format sensor has 75% of the width of a 1/2 format sensor.

With an imager twice as wide you would have a FOV twice as wide as well.

With a focal length twice as long you would have a FOV half as wide.

Of course imager sizes don't vary any where near the degree focal lengths do, which makes focal length more of a practical determinant.

Login to read this IPVM report.
Why do I need to log in?
IPVM conducts unique testing and research funded by member's payments enabling us to offer the most independent, accurate and in-depth information.

Related Reports

Axis IR Multi Imager Camera Tested (P3717-PLE) on Feb 18, 2019
Axis has released their first IR multi imager, the P3717-PLE, a repositionable model listing 360° IR illumination and flexible positioning,...
Hanwha Smaller Multi Imager Tested (PNM-9000VQ) on Feb 14, 2019
Hanwha's first repositionable multi imager PNM-9081VQ tested well, but was huge, over 12" wide and weighing in at over 10 pounds. Now, they have...
Bandwidth vs Low Light Shootout - Avigilon, Axis, Bosch, Dahua, Geovision, Hanwha, Hikvision, Uniview, Vivotek on Feb 08, 2019
Nighttime bandwidth spikes are a major concern in video surveillance, but do all manufacturers' cameras perform the same? Are some more consistent...
Sony Favorability Results 2019 on Feb 06, 2019
Sony Favorability amongst integrators improved moderately compared to their 2017 favorability results, with a modest net positive...
ONVIF Video Surveillance Tutorial on Jan 29, 2019
ONVIF is well known within the surveillance industry as an interface to connect IP cameras and VMS systems. However, new users may find it...
Access Control Turnstiles Guide on Jan 28, 2019
Turnstiles control pedestrian access to secured areas, essentially becoming moving portions of fences, walls, or barricades for physically stop...
Camera Course Winter 2019 - Last Chance on Jan 24, 2019
This is the last chance to register for the Winter 2019 Camera Course. This is the only independent surveillance camera course, based on in-depth...
Cable Trenching for Surveillance on Jan 21, 2019
Trenching cable for surveillance is surprisingly complex. While using shovels, picks, and hoes is not advanced technology, the proper planning,...
Testing Bandwidth Vs. Low Light on Jan 16, 2019
Nighttime bandwidth spikes are a major concern in video surveillance. Many calculate bandwidth as a single 24/7 number, but bit rates vary...
WDR Tutorial on Jan 11, 2019
Understanding wide dynamic range (WDR) is critical to capturing high quality images in demanding conditions. However, with no real standards, any...

Most Recent Industry Reports

Outdoor Camera Mounting Hardware Guide on Feb 21, 2019
Mounting cameras outdoors can be challenging, requiring understanding different types of equipment and methods. In this guide, we teach this...
HID Favorability Results 2019 on Feb 21, 2019
HID favorability results were strong, in the 2019 IPVM integrator study of 200+ integrators, with a net +62% and low negativity as the table below...
First US State, Vermont, Bans Dahua and Hikvision on Feb 21, 2019
The first US state, Vermont, has issued a ban on a number of Chinese and Russian manufacturers including the world's 2 largest video surveillance...
ADI 'SAVE BIG' On FLIR And Hikvision Examined on Feb 20, 2019
One is a major US defense supplier. The other is owned by the Chinese government. But you can "SAVE BIG" on both at ADI. In this note, we...
BluB0x Company Profile on Feb 20, 2019
BluB0x has doubled in revenue every year since its founding in 2013, according to CEO Patrick Barry. We originally reported on them in 2015. At the...
Security Installation Tools Guide - 22 Tools Listed on Feb 19, 2019
In this guide, we cover 22 tools that security installers frequently use. This is one part of our upcoming Video Surveillance...
Sales Cuts At Rasilient on Feb 19, 2019
Over the past 2 years, video surveillance storage specialist Rasilient has expanded its workforce significantly, aiming to build its own branded...
Exacq Raises VMS Software Pricing Twice in Less Than a Year on Feb 18, 2019
Most VMSes regularly release new features, but rarely increase their prices. For the 3rd time in 4 years, and 2nd time in 8 months, since being...
Axis IR Multi Imager Camera Tested (P3717-PLE) on Feb 18, 2019
Axis has released their first IR multi imager, the P3717-PLE, a repositionable model listing 360° IR illumination and flexible positioning,...

The world's leading video surveillance information source, IPVM provides the best reporting, testing and training for 10,000+ members globally. Dedicated to independent and objective information, we uniquely refuse any and all advertisements, sponsorship and consulting from manufacturers.

About | FAQ | Contact