Lens Iris Tutorial

By: IPVM Team, Published on Aug 08, 2019

Cameras, like humans, have irises, controlling the light which hits the imager and impacting image details. However, cameras have multiple types of iris options - fixed, manual, and auto, and variants of each which can be confusing for new users and over-hyped by manufacturers.

free image2

In this tutorial, we look at:

  • Iris basics: What they do and how they work
  • How iris relates to shutter speed
  • How iris relates to F-stop
  • How they opening or closing the iris impacts images
  • Auto vs. Manual iris options
  • DC auto vs. P-Iris vs. iCS lenses
  • Iris Type Rarely A Choice

In this tutorial, we explain the tradeoffs of each, how irises work and how they relate to shutter speed.

*******, **** ******, **********, *********** *** ***** which **** ************ ********* ***** *******. However, ******* **** ******** types ** **** ******* - *****, ******, *** auto, *** ******** ** each ***** *** ** confusing *** *** ***** and ****-***** ** *************.

free image2

** **** ********, ** look **:

  • **** ******: **** **** do *** *** **** work
  • *** **** ******* ********* *****
  • *** **** ******* ***-****
  • *** **** ******* ** closing *** **** ******* images
  • **** **. ****** **** options
  • ** **** **. *-**** vs. *** ******
  • **** **** ****** * Choice

** **** ********, ** explain *** ********* ** each, *** ****** **** and *** **** ****** to ******* *****.

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

Controlling *****: ****, *******, *** *-****

******* ******* ***** ******** by ****** ********* *** width ** *** ******* (iris) ** *** ****** of **** *** ******* is **** (*******). **** ******* **** and *******, ** **** are ********* ** ******* and *******, *** **** serve ********* ********.

****'* **** * **** iris ***** **** ****** open ** ****** ******:

iris closed opened

Iris **********

*** ********* ***** ***** an **** ****** **** fully **** ** ***** closed. *** **** ***** a ****** ** **** metal **********, ****** ******, using * ***** ***** motor. ****** *** ********* numbers ** ******, ********* on ***** **** (* blades ***** *****).

Iris ******* ** ********

*** **** *** *********** effect ** *** **** or ****** ** ***** is *******, ***** ******* how ******* ****** ****** light ***** *** ***** overexposure ** *** **** handle *** ***** ***** may ***** **** ******.

*** ***** ***** ***** a ************* ** *** effects ** ****, **** fully **** *** *********** to ***** ****** *** dark.

***** ***** ****** ****** over ****, *** ****** has ** ** **** to ****** *** **** light ****** ** ***** the ******* **********. ****** are *** *** ** do ****. ***** *** multiple **** ******* *******, detailed *****.

Effects ** * ****

**** *** ***** ** the ******* (****) ** adjusted, **** ****** *******, ********** **** **** (or ****) ***** ******. In **** *****, **** could **** ****** ** the ******'* ***** ** field (***) ***** ******* and ******* ******** *** of *****, ****** **** is ****** * ********* problem ** ************. *** our***** ** ***** *********** **** *********** *** examples.

Auto **** / *-**** / *-**

********* **** ****** **** in ***** ********: **** (DC ** *****), *-**** (precise), *** *-**.

  • ** **** **** ****** control *** **** ******* via ****** ***** **** the ****. ** **** iris ****** *** **** common, ***** *** * standard ***** ** **** the **** ** ********** by *** ******.
  • *-**** ****** *** * specific ******** ****** ** more ********* ******* *** iris, ***** ** ******** to ******* ********* ** image ******* **** **** iris ** ******* ******** conditions. *******,** *** *****, *-**** ****** ******* no ******* **********.
  • *-** ****** *** ********** new, ********* ** ****, ********* ** **** and ********. ***** ****** are ******* ** *-****, but **** **** *******, with *** **** ********* more ******** *********** ** the ******, **** ******* of *****, ****, ********** correction, *** ****, ******* of **** **** *******. I-CS ****** *** ****, with **** ******* ****** support, *** *********** ******* to *-**** ** ***** of **** *******.

***** **** **** **** and *-**** ******** *** connectors **** *******, **** are *** ***** **********. A ** **** **** lens *** ** **** on * *-**** ****** (though ******* ******** ******* iris *******), *** * P-Iris **** ********* **** not ********** *** **** a ** **** **** jack.

Fixed / ****** ****

****** ****-**** ** **** common, ***** *** *** lens ******** ***** ****** be ********** ** *** camera: ***** *** ******.

***** ****, ** *** name ******* ****** ** adjusted ** ***. ** is *** ** *** factory, ********* *** *** way **** ** ********* * ****. ***** **** ****** are ****** ** ***** form ****** *******, **** as ********* *** ****** cameras, *** ******** ** CS *** ***** ***** types.

****** **** ****** ***** the **** ** ** controlled ** ******** ******** a **** ** *** lens. ****** *** **** is ************ **** *** the *** **** ** all *** *** ******, manufacturers ********* ********* ******* manual **** ****** ****** fully ** **%+ **** to ******** *** ***** performance. ****** **** ****** are ******** *** ***** used ** **** ********** applications **** ** *** or ******* ******.

Iris **** ****** * ******

** *** **** ******** of ******* *****, **** type ** ******* *** the ****, ** *** most ************* **** *******(***** *** *******) ********* do *** *** *************** lenses. ****** **** ********* or ****** ********* ****** typically *** ****-**** (** rarely, *-****) ***** ***** focal ****** ****** **** as *** **** ***** and ******* ********* *** fixed ****.

*** ***** ***** *** cameras, ** **** *** found * ***** ********** in ***** ******* ******* iris *****. **** ****** gains *** ** ***** in ******* ****** ** in *** ******* * camera ******* ** ******* in *****, *** ******* other ******* **** **** impact. *** ****-**** **** *************** *** **** *******.

** **** ****** ******** P-Iris ** *-**, ** suggest ***** **, ** there *** ***, ** any, ********* *** **** limited ********* ********. *******, we ** *** ********* rejecting ******* ****** ******* they ******* **** ** auto ****.

*** ******* ** **** IP ******* ***** ********* adjust ********** **************** *** *************, ******** them ** ****** ***** strong *** ***** (**** shutter) ** ***** ******** (slow *******).

Test **** *********

**** ***** ******** *******.

[**** **** **** ******** was ********** ********* ** 2011, *** *** ******* in **** *** **** with **** ******** ******** and ********** *-**** *** iCS **** ***********.]

Comments (9)

******** ** ******, *** anyone ***** *** ******* yesterday **** * ******* Physicist ****** * *,*** year *** ******* **** will **** ****** ******* and *******? ** ***** like ** *** **** to ****** * ******* that **** **** *** whole ***** ******* ******* of **** *** ******. I ******* ** **** impact **** **** **** on *** ********.

*****://*******.***/*-*******-*********-******-*-*-***-****-***-*******-***-**********

**! ****** *** ** old **-** *** ****** it ** * *** minutes!

*********** ********* ** ********** lenses. * ******** ********** lenses ***** *** "*** new *****" *** **** speed ** *** **'*/**'*. Now ** ***** *** hear ******* ***** **. Is ******** ***** ********** lens ********** ***? ********* with ******** *** ***** sensor *********** *** **** for ****** **** ***** is *******, *** ***** are ***** * *** of ************ ***** **** speed ***** * **********. 

****, *** ****** ***** that ***** ** *****, "is ****** * ********* problem ** ************." ** you **** ********** ****-*****, I *****. ** *** do *** **** ****-*****, I ******* **'* ***** a *********** *******. **** is *** **** **** someone **** * ******* density ****** ** ******** focus * ******? * used ** *** *** call ***** ***, "*** man, ****** ***** ******** during *** *** *** everything ** *** ** focus ** *****. ****'* up **** ****? 

*****, ******* ** ***!

****’* *** ******* ** which #** ******:

***** **** **** *** it ** *** ****** Calculator :)

* **** **** ** well. * ******* ** will **** ****** ***** megapixel ******* ***** *** distortion **** **** ** the ****.

***** *** ***** **** clear ***** ** *** days **** ******* **** from */*" ** */*" and *******. ** ***** to ******* *** **** field ** **** ** smaller ******* *** ****** lower ** ******. *** axis ********* ********** *** very ******* **** ***** quality ****** ** ******* sensors, **** ** ******* and ***** *******.

** **** ***** **** Hikvision *** ******* *** their *** *** **** did *** **** **** iris.  ** **** ***** a *** ****** ******** around **** ** *** before **** *** *********.  I **** **** *** old ****** ********* *** physics ** ****** ******, light, *******, *** ****** functions.  (***, **** ***** course **** **** *** at *****).  ****** *** the ******* ********* *********** in *** ********** *** functionality ** ***** ********* camera ********.

*******, ****** *** *** info! *** *******, ***** Hikvision ****** ** ****? The * ******? ** something ** *** * series? ****** *** *** a ****** ****** ** they've ******* ****** ***** in *** **** ****** years.

**** **** ** **** do **** ****?

* ******* * *** from * *** ****** from ******* ******. 

** ****** ****** ***** that ******** **** * fixed “****”, ** ** they **** **** ** iris *** ********* * fixed ********?

 

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

Camera Focusing Tutorial on Oct 14, 2019
Camera focus is fundamental to quality imaging. Mistakes can significantly reduce details, making cameras less effective. In this guide, we...
Startup Spectral Edge RGB+IR Claims "Unique Low Light Performance Tech" on Apr 03, 2019
This UK startup, born out of university research, is boldly proclaiming that they deliver "Unique low light performance tech for video surveillance...
Lens Focal Length Tutorial on Jul 10, 2019
3mm, 6mm, 2.8 - 9mm, 5 - 50mm, etc. Camera specifications often list lens lengths but what do they mean? These metrics are important in...
Wide Dynamic Range (WDR) Guide on Oct 01, 2019
Understanding wide dynamic range (WDR) is critical to capturing high quality images in demanding conditions. However, with no real standards, any...
Lasers Impact on Surveillance Cameras Tested on Sep 25, 2019
Hong Kong protests have brought global attention to video surveillance and the ongoing attempts of protesters to disable or undermine those cameras...
Hikvision ColorVu is Smart Marketing on Oct 03, 2019
Hikvision ColorVu (see IPVM test results) is smart marketing, a lesson to be learned by competitors and a rising trend. Inside this note, we...
Integrated IR Camera Usage Statistics 2019 on Oct 21, 2019
Virtually every IP camera now comes with integrated IR but how many actually make use of IR or choose 'super' low light cameras without IR? In...
Biggest Low Light Problems 2019 on Nov 08, 2019
Over 150 integrators responded to our survey question: "What are the biggest problems you face getting good low-light images?" Inside, we share...
Hidden Camera Detectors Tested on Nov 18, 2019
Hidden cameras are a growing problem as cameras become smaller, cheaper and easier to access. However, some companies claim to be able to detect...
Budget Covert Cameras Tested on Nov 26, 2019
Covert cameras under $100 are widely available online but are they any good? To see how these models really work in the real world, we bought...

Most Recent Industry Reports

Masks Cause Major Facial Recognition Problems on Feb 24, 2020
Coronavirus is spurring an increase in the use of medical masks, which new IPVM test results show cause major problems for facial recognition...
Every VMS Will Become a VSaaS on Feb 21, 2020
VMS is ending. Soon every VMS will be a VSaaS. Competitive dynamics will be redrawn. What does this mean? VMS Historically...
Video Surveillance 101 Course - Last Chance on Feb 20, 2020
This is the last chance to join IPVM's first Video Surveillance 101 course, designed to help those new to the industry to quickly understand the...
Vulnerability Directory For Access Credentials on Feb 20, 2020
Knowing which access credentials are insecure can be difficult to see, especially because most look and feel the same. Even insecure 125 kHz...
AI/Smart Camera Tutorial on Feb 20, 2020
Cameras with video analytics, sometimes called 'Smart' camera or 'AI' cameras, etc. are one of the most promising growth areas of video...
China Manufacturer Suffers Coronavirus Scare on Feb 20, 2020
Uniview suffered a significant health scare last week after one of its employees reported a fever and initially tested positive for coronavirus....
Cheap Camera Problems at Night on Feb 19, 2020
Cheap cameras generally have problems at night, despite the common perception that integrated IR makes cameras mostly the same, according to new...
Milestone Launches Multiple Cloud Solutions on Feb 18, 2020
Milestone is going to the cloud, becoming one of the last prominent VMSes to do so. Milestone is clearly late but how competitive do these new...
Video Surveillance Architecture 101 on Feb 18, 2020
Video surveillance can be designed and deployed in a number of ways. This 101 examines the most common options and architectures used in...
UK Stands Behind Hikvision But Controversy Continues on Feb 18, 2020
Hikvision is exhibiting at a UK government conference for law enforcement, provoking controversy from the press, politicians, and activists due to...