Motion detection not very great

Purchased and installed a 3 cam system, moved cameras and tried different mounting positions with similar results. Do the cameras not pick up motion very well directly towards them? Any help is appreciated!

Wow, have same issue, surprised no reply yet to your issue…Like you, just trying to get some help. If you found solution, please advise!

Like most pir,s the cameras detect motion better from side to side .Just re position the cameras so they are not pointing directly at the area to cover

This is not only a Blink thing, it is most brands of cheap motion detection sensors. Study how and why a PIR sensor works. PIR is actually what the motion detector sensor is. It senses reflected infrared heat. That reflection is typically related with motion. The reflection can’t be directly at the sensor.

Thanks for all the replies, I’ll try repositioning and see how it goes! :beers:

Hi. I am a retired military mechanic
I also love to learn about technology.
When i was installing my cam system. I read that the cams do not pick up motion well straight on. There is a reason for this and its with in the cam lens and the program that blink uses to detect motion.
So aim your Camara to point left or right slightly to what is the focal point ie. My truck i park it generally in the same spot. Its my truck the cam will tell has motion for me its the cover on my bbq that’s on my front deck. Or its a stupid cat walking around near my truck. You can adj the sensitivity and then pick what areas to avoid detection. So for me i ask the camera to not see the bbq. Because this cam is my front door i get alot of alerts. I also aim the cam while i view it. This helps to get the thing u want to protect off center of the lens view ie my deck stairs are right in the center of the lens my bbq is off to the right of center. My truck. Is always off center to the left aiming this way will help detect what u want to see when u need to see it.
I hope this helps

Hi Smokey

Good advice, but since you say you enjoy learning how technology works, it might be worth pointing out that the difficulty in detecting motion, moving towards the camera, has nothing to do with the lens, or the software. Indeed the lens isn’t even active during this process, nor the Blink image analysis software, because the cameras aren’t even turned on.

Instead they rely entirely on the PIR sensor, which is a very low power method of detecting motion, and is pretty much the only part of the camera which is not in deep sleep mode at this point. This front on difficulty is an inherent limitation of most all PIR sensors and is a result of how they detect motion.

They are sensitive to infrared, and have two slits through which the IR passes. When the IR passes through a slit, it falls on a sensor and that creates a small voltage. It then compares that voltage to that from the sensor behind the second slit, and if the difference is above a certain adjustable threshold, the sensor triggers. This is what you adjust in the sensitivity setting in the app. When something approaches from the front, it’s common for both slits to be exposed to exactly the same amount of IR, and thus the change in voltage from the sensor is the same, so you do not pass the trigger threshold, unless it is set on very high sensitivity. When something moves across the sensor, invariably, each slit will be exposed to a different IR signal causing a voltage difference between the two sensors. If this difference is above the adjustable trigger threshold, the PIR will trip.

How this works in practice is that the output from the two sensors becomes the input to a differential amplifier, which when both inputs are the same it has a net output of 0. This allows the sensor to ignore the general background IR signal, which is present all the time. It also allows it to ignore the change you would get, if for example, a light was turned on, illuminating the entire scene, where the entire background IR would suddenly increase, but the increase would be the same for both slits, so the output from the differential amplifier would remain 0.

In the case of Blink, the PIR sensor triggering will wake up the camera, and then images can be taken, which will result in a recording, or, if you have activity zones set up, it will allow the camera software to perform image analysis, in line with how you have your zones set. If it now passes this further test, the recording will continue, and will be uploaded to the cloud.

More sophisticated PIRs have two pairs of slits, or even more, helping them to be sensitive in more directions, but for whatever reason, it would appear, based on observed behaviour, that Blink have gone with by far the most common type. You might even say the ‘bog standard’ version with a single pair of slits. Could be for any one of a number of reasons, but I suspect the most likely is cost. They are so common, in huge numbers, such as Blink would require, they would be incredibly cheap. With no trouble at all you can find them for under £1 each, delivered, on ebay, and that will hardly compare to what Blink/Amazon could achieve.

EDIT: Good picture that sums it up below:

Is the IR on at both day and night or just night? And is it better to have low ir or high ir for the most sensitivity

Wow ur ego must be Hugh

Who is Hugh? Does he have issues too?

Look dude, it’s pretty simple. I took the trouble to look up how they do work, some time back, and had some time a couple of days ago when you posted. You had some good points, with regard to positioning, which I acknowledged, but stated something that was incorrect, but you also stated that you like to learn, so I took the time to describe how they do work. One to correct disinformation, and two because you said you love to learn about technology. Had you not said you love to learn, I would not have bothered.

It’s now clear you have no interest in learning, and it’s also now obvious you’re the one with an ego issue, because you felt some strange need to tell us about your tech history, prior to your post, and now, oddly, you somehow feel offended or hurt because someone took the time to advise you about how something really works.

Very strange, but it takes all sorts.


I appreciated your post i found it informative. I am brand new to blink


Thank you for taking the time to share that information, bought my wifi cam today and it captures images only when i press the record or capture images. I’m going to work on it tomorrow but i think you’ve answered my question and it might not be fit for my purpose in this instance - still once i get it repositioned etc i’m sure the compromise wont be far off. Thsnjs again :+1:

Perhaps your sensitivity levels are set to low? My issue is the opposite. It picks up every single piece of motion and it’s only turned up halfway. If a bug farts and moves the leaf, it picks up the motion and sends an alert. I can’t wait until the Ring’s “People Only” feature makes it to the Blink platform. Right now I have way too many faults-positive alarms. I wrote and asked if this was part of the company’s road map, but didn’t get an answer.

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After several camera angle adjustments, and settings through the app, I’ve got my system dialed in. The angle of the camera itself makes all the difference when detecting motion. Thanks everyone for your input.

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