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?
- Ask the manufacturer specifically for each camera?
- 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?