Wide Dynamic Range (WDR) Guide

By Ethan Ace, Published Oct 01, 2019, 09:15am EDT

Understanding wide dynamic range (WDR) is critical to capturing high quality images in demanding conditions. However, with no real standards, any manufacturer can claim WDR, and many do even if actual performance is weak, causing confusion for even experienced users.

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In this tutorial, we break down these issues, explaining:

  • 2021 State of WDR
  • What is WDR?
  • Camera WDR Challenges
  • Solution: True Multi-Exposure WDR
  • Number Of Exposures Varies
  • True WDR Camera Improve Effective Details
  • How WDR Is Measured
  • Decibels Vs. WDR Ratio Measurements
  • Interpreting Manufacturer WDR Specifications
  • Resolution Vs. WDR
  • Multiple Exposures May Reduce Low Light Performance
  • Fake WDR Techniques
  • Backlight Compensation (BLC)
  • Digital WDR (DWDR)
  • Model Resolution Limitations
  • Manufacturer Terminology Confusion

2021 ***** ** ***

**** *** ** ******** increasingly ******, ****** *************** amongst **** ******* **** important:

*** ** ***** *** quite * ********* ******* found ** ***** ******, but ** ** *** closer **** **** ******. We ****** **** ***** to ********.

******* ** ****, ******** fine *********** ** *** performance ** **** ******* than **** ******, ** any ************ *** ******* their ****** ** "**** WDR" **** ** ********** of **** ***** *********** (and **** ********** **).

WDR **** ******** *******

**** ******** ****** ** cameras **** ***** ************* in ****** ****** **** ******** 2019*** ****** **** ***** on *********** ** ******** scenes.

** *** *****, ******* *****-*** ** *********** **** *******, **** strong ****** ******* *********, in **** ***** ** scenes, *****, *** ** motion, **** ******* ****** artifacts.

*** ***** ***** ***** the **** ********:

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*** **** ******* ** the*** ****** ******** ******.

What ** ***?

*** ****** *******************, *** ** *********** the ******* ** ******* high ******* ****** ****** a ***** ***** ** light ******. *** *******, in *** ***** *****, the ****** ** *** scene ** **** ****** due ** *** ******** behind *** ****** ** the *******, ***** *** scene ** ****** ****** of *** ******** ** it **** *** ******* direct ********.

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

******* ************ ********* **** wide ****** ** ******** because ** ***** ********** on ******* ********. ******* **** ***** to ******** ** *****. However, *** **** ***** and *** ***** ** washed ***, *** *** little ***** *** *** image ** *** ****.

** *** **** * scene **** **** ********, the ****** *** ****** adjust *** **** ******* size ** *** ******* speed ** *** *** right ****** ** *****. This ** *** ************* typically **** ***** ******* in **** ******** ******.

*******, ** *** ***** has * **** ***** of ********, *** ****** has * ***** *********. If ** ********* *** amount ** ***** ** takes ** ** ******** for *** ****** *****, the ***** ***** ***** will ** *** ****. However, ** ** ******* the ******** ********, ********** for *** ***** *****, the ****** **** **** be ****** ***. *** image ***** ***** **** tough ********:

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Solution **** *****-******** ***

***** *** **** ********* for *** ****** ** setting *** ******** ************* to ******* **** **** and ****** *****, *** most ****** ****** ******** is ** *** ******** exposures *** **** ******* them ** ******* * better ******* *****, ******** to ** **** *** or *****-******** ***. *** short ******** ******** *** bright *****, ***** *** long ******** ******** *** dark *****. *** *** representation *****:

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** *** *******, **** WDR *********** ** *********** beyond *** ***** ******* manufacturers ******* ** ******* WDR ******* (*.*., '*******' or '**********' *** ** BLC).

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

*** ****** ** ********* used ** **** *** varies, **** * ******* of * ** * or * ** **** models. *******, * ******* number ** ********* **** not ****** **** *** camera **** ******* ****** than ***** ***** **** two *********. ***** ********** techniques, ****** *******, *** other ******* *** **** a ********** ** ****.

************, *** ***** ****** of ********* *** ******* of ***** ********** **** are ****** ********.**** ***** ********* ********* and ***** ******* ********* if *** **** *** performance ** ****** ** challenging ******.

**** *** ******* ******* Effective *******

**** *** ******* *** make * *** ********** in ****** **** ******* light ******. *** *******, in *** ***** *****, the ****** ** *** left **** *** ******* WDR *** ***** **** rough ******* ********* ** *** *******'* face ******* ****** ***. By ********, *** **** WDR ****** ** *** right ******* ***** *** subject's ****, *********, *** clothing, ** **** ** details ** *** ***** behind ***, **** ** the ***** ***** *** trees, ******* *** *** overhead *****, *** ****.

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How *** ** ********

** ** ******** ** know *** **** *** range ** ***** ****** a ***** ***. *** generally ******** **** ** measure **** ** ************ is *** ******* (*.*., 58dB, *****, ***.) **** higher ****** ************* ********** stronger *** ***********. *************, these ************ *** *** standardized *** *** ** the ********** ** **** manufacturer, *** ****** ** trusted.

*************, *** ************ *** based ** * ******** test ********.* *********** **** ***** (below) ** ****, ********** numerous ****** ** **** from ***** ** *****. The **** ****** * camera *** ***, *** higher *** ** ****** and ****** *** *********** performance ****** **.

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*************, **** **** *** translate **** ** ****-***** scenes (*.*., **** *** I ****** *** ** front **** ******?). ************, testing ** ****-********* ** each ************ *** **** parameters *** *** ** standardized, *** ******** ****** by *** *************.

An *********** ********: *** *****

** *** *******, ** developed ** *********** ****-***** approach ** ********* *** tough * *** ***** is. ***** * *** meter, ** ****** *** brightest *** *** ******* spots ** **** *****. The ***** ** *** two ******** * ****** indicator ** *** *********** the ***** **.

** * ******* ******* outdoors, **** * ***** opening ** ** ******** area, *** ***** ** typically ***** ****, *.*., 25x ** ***** *****:

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*** *** ***** ** this ***** ** ~***, with *** **** ******* at *,*** *** *** the ******** ****** ***** at ~***. **** ** a ****** ***** *****, but ** **** **** much ******* ** *** tests, ** ******* ********* may ** ** ****** as **,***+ ***.

******* ** ****, ** recommend ********* *** ** the ****** ***** ** be ******. **** *** be **** ** * field **** **** *~$*** *** *****. ************ ****** ** performed **** *** *** or ***** ***** ** strongest ** *** ***** as *** ***** **** vary ********** *** ***.

Interpreting ************ *** **************

*** ****** ***** ******* manufacturer ** ************** ** they *** ****-******** *** not ********* *************, **** if *** ************ ** telling *** '*****', ***** is ** *** ** know ** *** ****** is. *******, ***** *** some ******** ** ********:

  • * *** ** ****** of **** ** **** almost ****** ***** **** the ****** **** *** support **** *** ** manufacturers **** **** ****** their ******* **** *** will ****** **** *** camera ** *** ** the *** '*****'. '*******', non *** ******* ********** are ********* ** *** range ** ** - 80dB.
  • * *** ** ****** of ***+ *******, *** not ******, ***** **** the ****** ******** **** multi-exposure ***. *****, ******, since ************* *** **** to ****** *** ***** they ****, ** ** not **********. **** **** to ****** *** **** own ***** ** ****** **** *******.
  • *******, **** ************* *** relatively ************ ** ***** WDR ** *******. *** example, ***** ***** **** of ***** **** *** cameras ** '****' *****. This **** *** **** they *** ***** **** a **** ******* ************ self-assigning ***** ** *****. Actual ******* ** ******** to ******.
  • ** *** **** *** years, ** **** **** manufacturers ********** *** ** race **** ************** ** 130dB ** *** **** 150dB. *******, ** *** testing, ***** ******* **** effectively ***** *******, **** some *****-***** ****** ************* 150dB ****** ******.*** *** *** ******** for ****.

Resolution **. ***

** *** *******, ** have ***** ****** *********** between ********** *** *** performance. **** ********** ****** may ** ***** ** 1080p, ***, ***, *** even **, ** *** poorly ********** ******.

*******, *** *** ************* offer ***** ***-**** *** performance ** ***** ******* resolution ******. *** *******, Avigilon's ** **/** ******* do *** ******* **** WDR, ***** *** ****** do. ** ********, **** offers ***** **** *** "Forensic ***" ** * series ****** ** *****, 5MP, *** ** **********.

******* ** ****, ***** should *** ******** ********** a ******** ***** ** WDR ***********.

Multiple ********* *** **** *** ***** ***********

***** ******** ********* ********* restricts *** **** * shutter *** ** ***, which ********* *** ****** of ***** ******* *********'* ******, ******** *** ***** performance. ******* ** ****, most (*** *** ***) models ********* ***** *** automatically ******* *** ** night, ****** **** *** not ** *** ** do ** ** *******.

*** *******, *** ****** camera ***** ******** ******* to **** *** **** light ** *** (***** on ****** *****) ***/** when ********* ** ***** mode (*/*).

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**** ** ** ********* setting ** ***** ** low ***** ** * priority *** *** ******** where *** ****** ** deployed.

Fake *** ********** - **** *** ***

************* ********* ****** *** pseudo-WDR ********** ** ***** alternatives ** *****-******** ***: Backlight ************ (***) *** Digital *** (****). *******, our ***** **** ***** that ***** ********** ****** do *** ******* ** even * *** *********** true *** ******.

Backlight ************

***, ** ********* ************, simply ******* *** (******) exposure ** * ******. This ** ****** **** when *** **** ** capture **** *** ****** or **** ***** ** the ***** *** *** both. ** ***** ***, you **** **** *** portion ** *** ***** better ** *** ******* of *** ***** ***** worse.

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**** ***-**** **** *** models *** *********, ***** a ****** **** ****** only *** ** *** installations ** *** ***********.

"*******" ***

******* ***, **** ***** as ****, ****, ** ********** *** is *********** * ******** adjustment ** ******** ******* of *** *****, ******* of *** ******* *****. DWDR *** ** ****** in **** ****** **** doing *******, *** ***** techniques ***** ** *** compare ** **** ***.

*** *******, ** *** comparison *****, *** ********* models *** ***** **** by ****. *** **** WDR ****** ** *** left ******** ***** ******* details ** **** ** better ******* ** *** background. ** ********, *** digital *** ****** ********* washes *** *** *******'* face *** ****** ******** details ** *** **** area ** *** *****.

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**** **** **** ************* offer **** ******* *** in ******** ** **** WDR, *** ***** *** easily ******* *** ***, such ******' "******* *******" **. "Dynamic ********". ****** ** ***** terms *** ***** ** our*** ***** *****(**** *****).

Some ****** ********** *******

************, ***** ********, **** manufacturers' ******* ******* **** WDR, *** *** ** maximum **********. **** ** found ** **** **/**** models ***** *** ***** true *** ** ** resolution *** *** ** the **** **** ********* resolution, ** ** ******* ********** ******** * **** to **** ** ********** (2560x1440 ******* ** *********).

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***** *********** *** *** very ******, *** ***** should ******* ****** ************** before ******** *** ** supported ** *** ***********.

WDR ************ ***** ***** *** ****** ********

******* ************* *** ** cryptic ***** *** *******, we **** *** ******** a **** ** ************* detailing ******* **** ******* ‘true’ (*****-********) ***, ‘****’ (digital/electronic ***), ** ****. We **** ******* ***** to ********* *********, ****** conventions, ***.

*** ** ************* **** cameras **** ******* ‘****’ WDR, ***** ***** **** of **** **** **** cameras **** ******* ******* WDR.

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*** ******* ******* ********* this **** *** ********** manufacturer *********, ****** **** our*** ************ ***** ***** and ****** **************.

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

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

[****: **** ******** *** originally ********* ** **** but *** ************* ******* in **** ** ******* advances ** *** ************ and ***********.]

Comments (11)

when performing the lux meter test, doesn’t the meter need to point towards the camera?

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Funny: 1

Yes, I grabbed that frame when he was mid-movement instead of when it was pointed at the camera. We'll fix that.

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That image has been replaced.

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cool! (though i think the captions might be out of whack)

Agree
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Funny

I don't know what you mean...

Agree
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Funny

by any chance did you havd to edit the Red ~100 Lux and ~2500 Lux tags on that new image before replacing?

when i looked at it right after you posted it, i could have sworn it had different values... i must have been mistaken, though.

in any event, the model was swapped from

to

this one, correct?

i guess you were fortunate to have another image around, with a different model, but the same scene and same. ~100 lux and ~2500 light levels :)

Agree
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Ethan I would had that all H5A and H5SL cameras from Avigilon now have WDR

Agree
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Informative: 1
Unhelpful
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Thanks, I noted that in the chart.

Agree
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Informative to note when purchasing to determine 'true WDR' as opposed to digital WDR or some made-up term for 'fake' WDR capability. I wonder though if WDR is absolutely necessary given that shutter speed, frame rates, imager and ISO can also correct lighting conditions depending on the environment.

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given that shutter speed, frame rates, imager and ISO can also correct lighting conditions depending on the environment.

No, not for WDR / high contrast scenes. The challenge with WDR scenes is that they combine areas with low light levels and high light levels, so simply having a single capture adjusting the shutter or ISO etc. would still leave part of the scene (either the low or high light levels) poorly captured. Does that make sense?

Agree: 1
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Yes, thanks for the feedback

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