True Or Fake WDR?

Is the only difference between true and fake WDR that true WDR has multi exposure while a fake WDR has a digital? Is there anything to do with the dB number being over/under 100?


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.

That's a solid rule of thumb but not guaranteed, just to be clear for others. I know you said 'usually' but I wanted to emphasize that people should still check.

Btw, some Sony true WDR cameras (with multiple exposures) are specified at 95dB, this is the most common cause for confusion. Sony is just being conservative, it does not mean others are better just because they self assign 120dB or 130dB, etc.

...but I wanted to emphasize that people should still check.

What do you mean by check? Ask the rep? Is that more reliable?

The most confirming sign that I have seen, outside of it literally saying 'multi-exposure', is when the max frame rate is cut in half with WDR on. Though you may need to look in the manual or have camera in hand to know this.

Check our cheat sheet or ask the company specifically if it is multi-exposure.

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.

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

Axis P3225-LV

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.

Keller, on Axis, see Axis WDR vs WDR?

We've used all 3 Axis cameras and they all do "true" WDR. For the last two (Q35 and P32) you can select one of several operating modes that may or may not support true WDR. Typically it is,

1920x1080 resolution, 30/25 fps, true WDR available

1920x1080 resolution, 60/50 fps, only digital WDR available

1920x1200 resolution, 30/25 fps, only digital WDR available

The P3384 is an older model and supports true WDR but you can turn it off and it might support the axis digital WDR mode when in their "lightfinder" low-light mode, not sure have not used the digital one. We installed the daybreak app that was featured on IPVM a few weeks ago with these cameras to turn off and on WDR mode based off sunrise/sunset.

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.