IMHO, If the spec says WDR, not DWDR, and the db is > 100, and the manufacturer is a known name (even if known to be low cost), then it is usually multi-exposure.
IPVMU Certified | 02/01/16 07:34pm
The dB number itself is not evaluated in a standard fashion across manufacturers, so one manufacturer's dB numbers are not comparable to another manufacturer's dB numbers.
Usually multiple exposure WDR is 'true' because it is the method that provides the best results. Digital methods are digitial tricks or tweaks that approximate true WDR, but don't really have much positive WDR effect.
For help, see our WDR Manufacturer Cheat Sheet and Camera Tracking note to help understand which marketing term means 'multiple exposure' and which ones mean digital. Some manufacturers use both implementations, so be careful to understand which type you're working with.
IPVMU Certified | 02/09/16 02:12pm
These are the cameras I did research on:
Axis P3384-VE : True WDR-dynamic capture and Lightfinder technology: Dynamic Capture: Up to
120 dB (0.5-500,000 lux) depending on scene
Form Factor: Dome Varifocal
Max Resolution: 1.3MP
CODECs: H.264, MJPEG
Axis Q3505-VE 9mm
Fake\True WDR: WDR-forensic capture performed by image processing although the camera finder app does state the it supports multi-exposure WDR: Up to 120 dB depending on scene
Fake\True WDR: WDR-forensic capture performed by image processing although the camera finder app does state that it supports multi-exposure WDR: Up to 120 dB depending on scene
As you will note, the last two cameras (Axis Q3505-VE 9mm and Axis P3225-LV)
I stated a result of: Fake\True WDR: WDR-forensic capture performed by image processing although the camera finder app does state that it supports multi-exposure WDR.
Doing some research I could not find a reference to “actual” multi-exposure function in the documentation on either camera. There was mention of the “Exposure settings” but nothing about changing the exposure settings to utilize actual multiple exposures. I have reached out to our AXIS representative to get clarity. I will post his response after I hear from him.
IPVMU Certified | 02/09/16 02:45pm
I see the confusion between the "capture" and "contrast" terms. Thank you for providing the white paper. I now see that forensic capture is a true "Multi-exposure" WDR which also has an image processor to further sharpen the image.