Determining Real Or Fake WDR?

A few collected statements on IPVM about WDR and dB measurements

Unfortunately, these measurements are not standardized, [and] at the discretion of each manufacturer and should not be trusted upon.

You simply can not use dB ratings to determine whether or not a camera is implementing multiple-exposure ('true') WDR or if it is using single-exposure ('fake') WDR...

I don't care what they call it, if it isn't using multiple exposures then it isn't 'true' WDR.

Unfortunately most manufacturers do not make their type of WDR (electronic / digital vs multi-exposure) clear on their datasheet.

So manufacturers are willing to fudge WDR dB numbers, but unwilling to state WDR type, and without knowing the type, we are unable to know if it is true WDR.

Assuming we don't want fake WDR, what do we do?

  1. Ask the manufacturer specifically for each camera?
  2. Test independently and judge on the results?

As for 1, Axis might respond, but will Dahua? Should we believe them if they say they have true WDR?

As for 2, can we determine just by looking at a camera whether it has true WDR? with testing?

Isn't there some danger in blindly equating 'true' WDR with multi-exposure WDR, since we don't want to be that guy everybody knows, 2 years from now, saying "that ain't true WDR", about some new, and improved but non-multi exposure WDR technology?

Is reasonable certainty impossible here?


"Ask the manufacturer specifically for each camera?"

Yes, if you ask a technical person at a manufacturer "Does Model X support multi-exposure WDR?" they will almost certainly know and tell you the truth.

You still can (and should if you have the resources) test but asking that direct question will help a great deal.

"Isn't there some danger in blindly equating 'true' WDR with multi-exposure WDR, since we don't want to be that guy everybody knows, 2 years from now, saying "that ain't true WDR", about some new, and improved but non-multi exposure WDR technology?"

The danger would be to simply hold fast to a belief without periodically re-evaluating it as technology advances.

For example, two years ago, we were extremely negative about non IP HD because of high price and limited availability (specifically HD SDI / HDcctv). Now, we are quite bullish because of the recent releases of CVI and TVI.

For now, multi-exposure = True WDR is valid. In the future, it may not be. That's why it's important for professionals to continue to stay informed as technology develops.

John,

Is there any interest or plan to create a list of "True WDR" camera models? I am wondering if the models we rely on would make the list.

Currently, we generally use the Samsung SNV-6084R Wisenet III camera for WDR applications.

Yes, we are working on a 'cheat sheet' of which models are multi-exposure WDR and which are not.