IPC-B54IR-Z4E S3 and IPC-B52IR-Z12E S2 have different spectral sensitivities in B&W

[guykuo]

I first noticed a difference in how visible light appears in one camera, but not as much in the other when my Z4-S3 and Z12-S2 are in B&W mode. They don't see the same image. It was not just a light level / sensitivity issue, but their sensitivity to visible light differ. The following two image caps really bring out the difference.

Here is the Z12-S2



Now look what the Z4-S3 sees



It is a really stunning difference. The paint job must have very different contrast in visible vs IR wavelengths and the cameras have a surprising different result. This might be why the Z4-S3 has anecdotal better capture of printed (non-stamped) license plates.

 

[bigredfish]

Interesting, though some of it could be simply angle? were the two captures at approx the same time?

 

[guykuo]

Same time. The cameras are mounted 116 mm from each other (side by side). Van is about 40 yards from camera. So, view angle is basically the same for both cameras.

 

[bigredfish]

hhmmmm Is that a moving vehicle or stationary?

 

[97JeepXJ]

I’ve noticed some headlights can be invisible to the Z12, to the point I said something in our “neighborhood” group chat one time (dead end gravel road with 25 houses or so, I’m the first one) and another neighbor called the sheriff. After reviewing footage from a 5442-ZE it was obvious they were definitely on and I had to call off the cavalry. We were on high alert at the time as someone had just recently been down here and stolen a gun out of a locked vehicle (busted a window out) parked in their driveway.

 

[guykuo]

Moving. You can see the 3D NR ghosting in the Z12-S2 image.
Here is a video clip showing the Z12-S2 then what the Z4-S3 sees. Cameras are not at same zoom. So, I have cropped to be similar and dropped resolution to 1080P to reduce file size. You can see the paint job simply does not look the same between the cameras.
View attachment Paint IR.mp4

 

[bigredfish]

Wow!

 

[97JeepXJ]

It seems this is proving the B54IR-Z4E S3 is the better option for LPR if the distance works out. Some of us still need Z12. Oh, Annddyyy @EMPIRETECANDY

 

[EMPIRETECANDY]

z4e is bit good, have a lot of talking here. @Parley have bought several of this one, he post lots of good results on this link.
Mini-Review - 5442-Z4E-S3 AKA B54IR-Z4E S3 - Replacement to the 5442-Z4E | IP Cam Talk

Z12E also good, but Z12E can do longer range and do little better at low light place.
Mini-Review - 5241-Z12E-S2 - Replacement for the 5241-Z12E | IP Cam Talk

 

[guykuo]

I’ve noticed some headlights can be invisible to the Z12....

That goes along with some porch lights on a house being very dim on Z12 but well lit on Z4. That was with the rest of the house looking the same on both cameras. The Z12 -S2 is doing something interesting regarding visible light when it goes to B&W mode. It's almost as if it flips in an IR pass filter instead of just moving an IR cut out of the way.

Look at the grass in my video clip. Grass is quite IR reflective. See how it is brighter on the Z12-S2 than the Z4-S3?

I wish I had a means of measuring spectral response for the cameras. The curves would be interesting.

 

[TheOtherMike]

Z4 captures better (brighter) image of driver.
Plate looks more readable with Z12.