Using the Wyze Cam OG Telephoto for license plate capture

[wtimothyholman]

Even since the OG Telephoto was announced, I’ve been wondering how well it might work for license plate capture (LPC). I just got my OG Telephoto yesterday and decided to put it to the test. I aimed the OG Telephoto at a spot on the roadway 70 feet away from my home. I have a Dahua varifocal camera recording that same spot for my LPR system, so I have a good idea of what to expect in terms of optical performance.

Here is what I found:

(1) A license plate recorded by the OG Telephoto can be read in daytime, provided the plate is stationary. The 3X optical zoom is sufficient to make it legible at 70 feet, but I’d say it’s close to the limit of distance. A 5X or 7X option (which Wyze experimented with) would do much better.

(2) A license plate on a moving vehicle is entirely a different matter. The problem isn’t motion blur, but compression. The OG Telephoto provides a sufficiently fast shutter time in daylight to easily capture a vehicle going 30 mph at 70 feet distance without blurring, but the lossy compression washes out the detail of the plate itself.

Optically, the OG Telephoto is capable of recording the license plate of a vehicle driving by a typical residential home, at least during the daytime. While I recognize the necessity of a highly compressed video stream for reducing bandwidth over a 2.4 GHz WiFi connection, this is one of those situations where you can only say: “I wish Wyze had done it differently”.

I’d love to see an option provided for adjusting compression at the expense of increased storage, at least for video stored on the internal SD card. Wyze could also solve the bandwidth problem with a PoE camera option.

Here’s the thing: Wyze could own the residential LPC market with just a few tweaks to the OG Telephoto. Increasing the zoom to 7X and adjusting the compression would give them a product that every homeowner concerned about mail theft would buy in an instant. No other cloud camera manufacturer (to my knowledge) has even attempted true optical zoom, but if Wyze offered an LPC camera for under $50, they could transform neighborhood security, at least for daytime operation.

Nightime operation is another matter, as effective LPC would require a strong IR illuminator coupled with shutter speeds on the order of 1/1000 to 1/2000 seconds at night. That would be more difficult, but by no means impossible. So maybe the price of a Wyze Cam LPC goes to $80 or $90, but that would still be a bargain compared to the competition.

[habib]

Wow! Thanks for the honest post.

[sv11]

Hi,
It can record license plates from about 30 feet away during day. Also it needs good sunlight, has trouble during dawn and dusk. I am using OG Tele from inside using V3 window mount, but am going to move it outside to see if it helps.

sv11

[wtimothyholman]

The 70 foot threshold matters because it is very typical of the distance of a home from the street in my neighborhood. I’m going to try testing over shorter distances tomorrow to see if I can determine the threshold for license plate readability.

The ability to set a fixed shutter time would ultimately be required for reliable LPC, along with some supplemental illumination in the evening, at dawn, and at dusk. My Dahua varifocal camera can easily illuminate a license plate at 70 feet with its internal infrared diode, so it is certainly possible. The question is whether Wyze would be willing to incorporate such a feature into one of its cameras.

I keep reading about upcoming “pro” versions of Wyze cameras that will be hitting the market this year. I am hopeful that one of them will be optimized for license plate capture. From the standpoint of optics, they already have something that works.

[wtimothyholman]

I did some more tests today and my results agree with yours. At a distance of approximately 25 to 30 feet, the plates become readable for vehicles passing by at 25 mph in the daytime. I have to say that I’m impressed by the default daytime shutter speed; motion blur is negligible. If it wasn’t for the lossy compression of the video stream, the OG Telephoto could read plates at a much greater distance.

But this result does indicate that an OG Telephoto with an optical zoom of 7X would probably be able to read plates at a distance of 50 to 70 feet, even with the same compression.

UPDATE: I remeasured the distance from the camera to the road, and I would now estimate that license plates become readable at about 40 feet. To play it safe I would recommend no more than 35 feet from the camera to the area of the road you want to monitor.

[carverofchoice]

Great testing! Thanks for sharing!

[wtimothyholman]

As a followup I did some nighttime testing for a stationary license plate. Surprisingly, the camera can also read a plate up to 70 feet at night in color mode. In fact, color mode actually works better than B/W night mode due to the reflected glare of the IR diode illuminator.

The OG Telephoto could potentially be used to record license plates of parked vehicles in a lot, day or night.

[IL1]

Thank you for your tests! I’m debating between adding telephoto vs V3 pro for me to capture cars parked in the driveway and this is great to know.

[bigwig]

Honestly, There would be a huge market for residential LPC market. Is it on the wishlist? @wtimothyholman @carverofchoice @sv11 @IL1 @habib

[IL1]

It is on the wishlist and I just voted for it, but I’m afraid Wyze hasn’t really looked into this yet.

https://forums.wyze.com/t/license-plate-scanner/152880

Also it might be helpful to check out this license plate test by LifeHackster:

https://m.youtube.com/watch?v=ZqnW05lUHzY

I do have a lot of motion lights/spotlights around my driveway so one of these days I’ll spend time to find a spot where I can put a new camera to capture license plates without glare at night time.

[carverofchoice]

IL1 posted a good wishlist item for this. There is another similar one here too:

License Plate OCR

Hi there! It is an amazing camera and very affordable and simple, congratulations! My suggestion is to include “license plate” reading or recognition (OCR) this way we can use in community surveillance. For instance, in my case, my idea is get together with my neighbors and buy 10 or more and place them in strategic locations in my street and surrounding areas. With this feature we will have full control of car traffic in my neighborhood in addition to pedestrians. This is a great tool for ow…

[wtimothyholman]

Wyze wouldn’t need to develop a true LPR camera with optical character recognition. That would be overkill for 99.9% of residential homeowners. Instead, an LPC (license plate capture) camera would be more than sufficient.

The optics and electronics of the OG Telephoto are already capable of LPC in the daytime. Given a higher zoom lens (e.g. 7X) with the ability to adjust the shutter time and reduce the lossy compression (i.e. less compression with higher bandwidth), and I would bet that one could also capture plates at night from 60 to 80 feet away with sufficient illumination.

I’m tempted to crack open an OG Telephoto and see if I can locate the light sensor in order to modify the camera so that it thinks it is always daytime. This would set frame rate to maximum and shutter time to minimum, to provide a baseline for nighttime LPC performance.

A couple of OG LPC cameras (one in each direction) combined with a third wide-angle OG camera to provide context would be a perfect solution for the homeowner who wants the license plate of the car that was driven by a package thief, or who sideswiped their mailbox.

[wtimothyholman]

@IL1

Also it might be helpful to check out this license plate test by LifeHackster:

https://m.youtube.com/watch?v=ZqnW05lUHzY

LifeHackster makes the same mistake that many others do with nighttime LPC, by assuming that the IR glare will prevent reading the plate.

The solution is to set the shutter speed to a very low value (0.5 to 1 milliseconds) at night, just as you would for daytime operation. If you do that, the image will be very dim, to the point where all you see is a readable plate illuminated by the IR light. A properly calibrated LPC camera will show the plate along with very dim headlights or taillights at night.

If you do this, the LPC camera will be useless for determining anything else (vehicle type, color, etc.) So you need a “context” camera to provide the wide view of the scene.

A camera optimized to show the “big picture” won’t work for LPC, and vice versa. The mistake many people make is to try to make one camera do both.

[carverofchoice]

@wtimothyholman

modify the camera so that it thinks it is always daytime. This would set frame rate to maximum and shutter time to minimum

I was pretty sure when I tested on other Wyze cams that all you have to do was set the “Night Vision Mode” to “Off” and then it stays in daytime mode with 20FPS. It is when you set it to nightvision mode that it changes down to 15FPS. No physical modification or voiding the warranty needed to keep the FPS at maximum.

[wtimothyholman]

Thanks, that is useful to know. But the frame rate is only part of the problem. You have to set the shutter time to a very small value. Wyze would need to provide some means for the user to manually adjust it.

[IL1]

If Wyze can make a telephoto lens that can do that I would buy it and add it to my OG. They can call it night time anti-glare telephoto or something like that without advertising it can potentially read license plates. Might be worthwhile to vote for this too:

https://forums.wyze.com/t/wyze-cam-og-other-lenses/258014

[habib]

@wtimothyholman

But the frame rate is only part of the problem. You have to set the shutter time to a very small value. Wyze would need to provide some means for the user to manually adjust it.

…and open another can of snakes. You have to keep in mind that not everyone knows what shutter speed or frame rate is. Put yourself in a general user shoes and you’ll get my point.

Most of Wyze users (and I don’t mean any disrespect) are everyday users with not much technology knowledge. All they want is a camera/gismo that works out of the box without much fumbling around.

[wtimothyholman]

I don’t disagree. The average user just wants to pull it out of the box and make it run without any adjustments. However, ease of use and ease of customization are not mutually exclusive. It would be straightforward for Wyze to maintain a default configuration that works for 98% of users, but also include an advanced settings menu for more sophisticated users. You can see this in various devices where you can access a menu that warns you, “Don’t adjust these settings unless you know what you’re doing.”

[habib]

@wtimothyholman

You can see this in various devices where you can access a menu that warns you, “Don’t adjust these settings unless you know what you’re doing.”

I totally agree but I also see Wyze’s point of view, less headaches

[muerte33]

This would be a great product! I could see running a single POE line out to my mail box that feeds two cameras with a splitter. One camera gets the cars going in, and one gets cars exiting. What type of software is available to pull the license plate numbers and add them to a small database with in/out times, and maybe a picture of the vehicle too?