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 (10)

******** ** ******, *** 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 ********?

 

***** ******* ****! ** is **** *********** ***********.

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