The Samsung Wisenet 2MP camera claims 120db WDR, as do the Hikvision Pro Series.
Inaxsys Security Systems | 02/09/15 06:20am
Panasonic has a number that specify 133 db, see here for an example.
We don't support searching by db for WDR because it's highly inaccurate and manufacturers can make it up (like minimum illumination for low light).
Samsung and Hikvison both rate some of their cameras for 120dB WDR. Vivotek rates some of theirs at 140dB. The newest Panasonic includes cameras at 133dB. Axis 'true' WDR Q16 cameras say 'up to 120dB'. Sony Gen 6 true WDR cameras say 'up to 130dB'.
If this is a bid spec, you can look at that but I really think you should push back against this as may unfairly knock out manufacturers that are good in low light but conservative in specs.
This market is rife with must-meet project specs and without test verification, lower-quality cameras focused on meeting paper specs at lowest cost can win - hurting security and the industry overall.
For example, usable dynamic range is often limited by lens flaring and a theoretical number based on how many exposures are used (which is what some manufacturers use) is misleading, we all know that.
A 100dB spec camera with an appropriate lens, motion de-ghosting, and sophisticated tone mapping may outperform one specified to 120dB. Further, line/pixel-interleaved exposure perform better than frame-based due to less motion artifacts and a larger shutter window for low light.
The wide dynamic range dB number seems to be as valid as the low light lux number... IPVM can do some good here with a standardized dynamic range test.
I and the R&D team I was with at the time (2013-2014) tested and evaluated EVERY manufacturer claiming high Db for WDR.
Sony's 4-exposure Xarina provided the best overall combination of High Dynamic Range, Low-Light performance and Color accuracy, though it's better to move it to 2-Exposure in-low light to allow for longer exposure time.
I never once found Vivotek's claim of 140Db to provide actual better WDR than Sony Xarina. Vivotek's WDR is certainly excellent and scored top marks, but it's not the best WDR available.
Keep in mind that Vivotek DOES NOT develop its own Imagers, though they do develop some of their own Encoders/DSP silicon, whereas Sony Xarina is a combined, matched imager/DSP set. I'm not rah-rahing for Sony here, I'm just sharing with you the elevator speech of a long set of testing I did in 2013 and 2014 to evaluate actual relative WDR performance.
John's point is 100% correct, there is no way today to evaluate a WDR Db Spec relative to other manufacturers, because there is no universally accepted way to test WDR. Customers who make their buying decisions about WDR solely based on the Db rating on the Spec sheet would be well-advised to NOT do that, and TO ACTUALLY DO comparison video testing before they make their final buying decision. Particularly if WDR is the primary need of their application.
No I'm not saying Db numbers are generally indicative of top-notch WDR at all. I've seen plenty of no-name or unknown of manufacturers claiming 120Db with a product that couldn't possibly provide that high of Dynamic Range. What I'm saying is that you need to dive deeper into the technology under the hood, and ultimately do a shoot out. YOU SHOULD NOT ASSUME THE SPEC SHEET WITH THE HIGHER WDR DB RATING IS THE BETTER CAMERA.
I cannot sketch out methods, because to do so would violate confidentiality for my previous employer.
I also don't want to cast stones on the worst offenders. But generally speaking, if it's a company that's using Digital WDR and claiming a high Db, it should be suspicious. If the manufacturer cannot accurately explain to you the interaction between the imager and the DSP in creating solid WDR, you should be suspicious.
Thank you for your clarifications.
I think the spec overreach is predominantly done by those who are using true WDR to differentiate themselves from everyone else using similar technology, and with the knowledge that verifying the accuracy of the spec would be difficult or impossible (just like it is with low-lux ratings.)
People are spec-driven by nature. The same is true in the Consumer Electronics World, where TVs are selected (assuming two competing models are similarly priced) with things like brightness, contrast ratio and refresh rate.
Many times (and this is absolutely the case with camera specs like temperature rating and environmental IP rating), a customer will choose the highest spec without even needing that spec for their application, and will simply assume the higher spec'd product is "better". I see many jobs in the desert that demand IP67 even though it's the desert and the product will never be submerged in water, and an IP65 or IP66 product is more than adequate for their application. They'll likewise choose a product that has a 75°C rating over one that has a 70°C rating even though the hottest it will get in the Middle East is 54°C. Because the 75°C product has to be better, right?
Unscrupulous manufacturers know of this human condition and will spec their products accordingly.