which setting causes 5241E-Z12E blur with even slow motion?

[carteriii]

The picture below has been cropped but otherwise has not been edited, even though it looks like someone used photo-editing software to blur the license plate on the left.

I can't control the cars that drive by, so I manually put an old license plate and circular reflector on the right side of the road to help dial in the settings. The left license plate is on a car that is moving just 1 mile per hour. The camera is at a distance of about 135ft, at a 20-30 degree angle, with IR manually set on full blast.



Normally when something isn't clear due to motion, I think of shutter speed, but the shutter speed here is 1/2000th of a second so I'm confident that's not the issue given that the car was barely creeping. I believe some setting in the camera is causing the camera to do processing on the image that makes the moving license plate such a mess. Sharpness was my first guess, but I already have that dialed down to 10 so I don't think that it. I'm going to play some more this weekend, but given the screenshot below with my settings (& firmware version), does anyone have any educated guesses, ideally with an explanation of how/why this is happening?

Note in my settings that backlight is entirely off (so not even using the headlight compensation), and sharpness has been dialed way down. Contrast is up, and that obviously manipulates dark & light areas of an image, so perhaps that's the cause (& next thing that I'm going to try adjusting), but I can't think of a reason why slow motion combined with any contrast setting would result in such a mess. I just read one comment in these forums that some cameras with gain above 50 can be a problem, so I'm going to try testing that as well, though I also can't think of a reason that gain would have such an impact as it relates to motion.

Any other educated thoughts/ideas?

 

[wittaj]

At night, do not do a range either do 0.5-0.5 or 1/2000.

The shutter is trying to adjust and could blur it do to the headlights.

Also keep in mind the more zoom, the smaller the area of focus, so a plate on the other side of the street may make it blurry when a car goes by.

 

[carteriii]

@wittaj , you're awesome! I'll make that change right now so I can see if that's it when the first car goes by tonight. Thank you!

Regarding focus, I went for manual focus on that spot at that distance to try to eliminate the focus as a variable in my problem. With that image above, I tried to capture the moment that the moving car plate was at the exact same distance as my stationary plate on the right. I forgot to mention that in my first post.

 

[Flintstone61]

If your lens is focusing on the still plate, the moving plate could be out of focus.

 

[Flintstone61]

Maybe use only the smaller reflective device?

 

[carteriii]

If your lens is focusing on the still plate, the moving plate could be out of focus.
Maybe use only the smaller reflective device?

Thank you. I won't use the stationary plate at all in my next round of tests, and the small reflector is fixed (not put there by me) so it will remain. By using fixed focus I didn't think I'd have an issue with the camera changing focus, and the depth of field does show plates in focus some distance ahead/behind that spot (when the object isn't moving), but I'll try a few experiments with that as well.

I'm hopeful that wittaj's observation & suggestion will be the solution. If not, I may need to convince my wife to drive back & forth multiple times while I'm at the computer to be able to run more tests than simply sitting around waiting for the next car.

 

[samplenhold]

Things to think about:

Are the plates in daylight in focus? Have you written down the zoom and focus numbers and verified they have not changed?

Below are my numbers to compare against.

Another thing is this looks like to me an issue with bit rate. I run mine as below.

 

[Flintstone61]

My Z12 performs better when I leave it on my night setting, ( no color) with IR set to Auto to kick on at night. I have a different use case though. 70 feet and 18 mph cars.
My cam is focused right at the asphalt so it wont hunt. cars are trapped thru a choke point. and at least 3-6 frames will have the plate. However, It has been affected like yours when the plates were salt coated.

 

[Photon Farmer]

Have same model camera.
Capturing license plates at about 170-180 feet at about 30 degree angle.
I had a problem.
Plates would be in focus at right and left edge of view but always out of focus in center of capture.
So moving plate would be in focus at shorter and longer distance at each edge of capture but always out of focus at middle distance in center of capture.
Tried just about everything.
Finally, when i dropped Iris down to 55 focus was good across whole capture.
Lowering Iris worth a try.

 

[Flintstone61]

I run at 12 FPS.

 

[Steve.L]

@samplenhold's settings were the dope for my setup right out of the box, a few zoom and focus tweaks, and the creeps can't squeak by! Like Flint dude ^^ I'm getting about 6 frames at 15 FPS, one of 'em is zoomed all the way in at 1200.

 

[Steve.L]

Have same model camera.
Capturing license plates at about 170-180 feet at about 30 degree angle.
I had a problem.
Plates would be in focus at right and left edge of view but always out of focus in center of capture.
So moving plate would be in focus at shorter and longer distance at each edge of capture but always out of focus at middle distance in center of capture.
Tried just about everything.
Finally, when i dropped Iris down to 55 focus was good across whole capture.
Lowering Iris worth a try.

Very interesting, I too have fuzziness in the middle and crisp clarity on the left and right sides, I'm gonna try this tonight. If I recall, it's only on one of my LPRs.

 

[samplenhold]

Another thing I thought about...If you step through the video one frame at a time, is there any position that it is fine? Or do parts of the plate workout while other parts are bad?

 

[richardgohth]

The picture below has been cropped but otherwise has not been edited, even though it looks like someone used photo-editing software to blur the license plate on the left.

I can't control the cars that drive by, so I manually put an old license plate and circular reflector on the right side of the road to help dial in the settings. The left license plate is on a car that is moving just 1 mile per hour. The camera is at a distance of about 135ft, at a 20-30 degree angle, with IR manually set on full blast.

View attachment 126689

Normally when something isn't clear due to motion, I think of shutter speed, but the shutter speed here is 1/2000th of a second so I'm confident that's not the issue given that the car was barely creeping. I believe some setting in the camera is causing the camera to do processing on the image that makes the moving license plate such a mess. Sharpness was my first guess, but I already have that dialed down to 10 so I don't think that it. I'm going to play some more this weekend, but given the screenshot below with my settings (& firmware version), does anyone have any educated guesses, ideally with an explanation of how/why this is happening?

Note in my settings that backlight is entirely off (so not even using the headlight compensation), and sharpness has been dialed way down. Contrast is up, and that obviously manipulates dark & light areas of an image, so perhaps that's the cause (& next thing that I'm going to try adjusting), but I can't think of a reason why slow motion combined with any contrast setting would result in such a mess. I just read one comment in these forums that some cameras with gain above 50 can be a problem, so I'm going to try testing that as well, though I also can't think of a reason that gain would have such an impact as it relates to motion.

Any other educated thoughts/ideas?

View attachment 126686

looks like some auto gone crazy
I wld off everthing auto such as Backlight, headlight blanking ( if any ), smart anything, defog etc
Increase the video bandwith to max.
if possible fix the shutter and gain.

 

[carteriii]

I think switching to fixed shutter speed (rather than 0-0.5) has helped, but I still see the odd behavior of blurring with motion which I haven't yet figured out. I'm going to call it quits for the night, but I captured a video that I'm sharing below and might help people identify whatever is going on. Here is a video of a car approaching a gate. The license plate is badly blurred until the driver stops to wait for the gate, when a fraction of a second after stopping the license plate becomes completely clear.

The driver starts moving again 10 seconds later and then you'll see the blur immediately starts again as soon as movement happens, though this time it's not nearly as bad and the license plate is at least readable.

I am also including my stream settings below which I did not include previously. I just noticed that I selected a bit rate of 4096 which was the highest in the drop-down selection list (given the other settings, which dynamically change the list), but the reference bit rate shows a max of 5120 so I'll switch to "custom" and set the bit rate to 5120 just in case that's causing any issue.

Any new thoughts after seeing this video?

 

[richardgohth]

I think switching to fixed shutter speed (rather than 0-0.5) has helped, but I still see the odd behavior of blurring with motion which I haven't yet figured out. I'm going to call it quits for the night, but I captured a video that I'm sharing below and might help people identify whatever is going on. Here is a video of a car approaching a gate. The license plate is badly blurred until the driver stops to wait for the gate, when a fraction of a second after stopping the license plate becomes completely clear.

The driver starts moving again 10 seconds later and then you'll see the blur immediately starts again as soon as movement happens, though this time it's not nearly as bad and the license plate is at least readable.

I am also including my stream settings below which I did not include previously. I just noticed that I selected a bit rate of 4096 which was the highest in the drop-down selection list (given the other settings, which dynamically change the list), but the reference bit rate shows a max of 5120 so I'll switch to "custom" and set the bit rate to 5120 just in case that's causing any issue.

Any new thoughts after seeing this video?



View attachment 126711

looks like slow shutter
no way its 1/2000 sec
at such shutter shld be rather dark

 

[richardgohth]

looks like slow shutter
no way its 1/2000 sec

try H.264 encoding

 

[richardgohth]

try H.264 encoding

confirm main stream?

 

[samplenhold]

Second switching to H.264 and going as high as you can (8192) on the bit rate.

 

[carteriii]

I just switched the camera to H.264 and 8192 kbps so we'll see how this does tonight. Thank you all!

looks like slow shutter
no way its 1/2000 sec
at such shutter shld be rather dark

I agree it seems like a shutter speed issue, but I really have used both the custom 0.5ms setting and now the explicit 1/2000th shutter speed. I did experiment with 1/4000th and saw the same behavior, so unless my camera's shutter speed simply isn't working, I don't think that's it. If it matters, daylight images are fantastic and completely in focus for a wide range (near to far). As for the brightness of the license plate, particularly when the vehicle was still, it definitely is/was dark before I bumped up the iris & gain. Having said that, I appreciate your comment and will also do some more experiments with the iris & gain lower, letting the image be darker, and see if that changes the blur during motion.

For the benefit of anyone who hasn't done much still photography, particularly with manually setting old school f-stops (which I have used for many, many years), opening the aperture physically lets in more light while reducing the focus depth of field, at least on a traditional still photography "camera". Given that the iris is the equivalent of an still photographic aperture/f-stop (explicitly stated by Dahua: DahuaWiki), I ASSUME that increasing our video camera iris also reduces the focus depth of field, though I don't know that for certain. I also don't know what other side-effects happen from increasing the iris further. In my settings, I used my knowledge of still photography (which I recognize is not 100% relevant with these video cameras) to find the highest iris setting that gives me a sufficient depth of field (which really matters when using a fixed focus point) and THEN I bumped up the gain, which in still photography would increase the grain of the image. I don't claim that's the best approach for these video cameras, but it was my personal thought process based on still photography principles. I'm super happy with how the license plate looks when not moving, and now hoping the H.264 use may help whatever is causing such extreme blur with even minor amounts of movement.

I do believe the license plate is & should be out of focus when the video above starts with the vehicle at a distance, but I don't believe focus explains what we're seeing immediately before & after the vehicle stop moving when the image is severely blurred with movement of only a few inches.