Night time camera selection w/motion involved

[DanDenver]

Everyone shops for a camera with a different approach to what might be the best camera for their install.

I always check MP against sensor size as a way to remove undesirable cameras from my search.
Once I found a camera with a desirable MP and sensor combo, I would then dig deeper on FOV, price, etc.

So I made a chart showing what combinations of MP and sensor size are most desirable from a NIGHT TIME MOTION perspective.

This chart has no real bearing on day time viewing or static viewing as there is enough light during the day for almost any MP/sensor combo to work.
We want our cameras to operate under worse case scenario, which for many of us would be during the night:



For distance and field of view, you might try this interactive site:

Lens Calculator

www.jvsg.com

 

[wittaj]

Great graphic that should help NOOBs out!

How many budget cameras do we see on the 1/3" sensor? That is only good for 720P, yet people purchase 8MP on this sensor all the time and then wonder why the camera doesn't perform well at night.

 

[Mike A.]

Yes, good job.

 

[Frank888]

Why that big jump of 1-3 MP from 1/3 to 1/2.8? The pixel size will be much smaller = more noise

 

[wittaj]

Why that big jump of 1-3 MP from 1/3 to 1/2.8? The pixel size will be much smaller = more noise

Yes and no. If they were both on the same size sensor, then yes you are going to see more noise. But these sensors are small, and every jump in sensor size actually represents a decent jump in size from a percentage standpoint.

The following is generally the accepted MP/sensor ratio sizes based on user performance and experience and converted to bullet size thanks to @sebastiantombs:

Disclaimer - These sizes are what the manufacturers advertise and may, or may not, be the true size of the sensor in the camera.
720P - 1/3" = .333"
2MP - 1/2.8" = .357" (think a .38 caliber bullet)
4MP - 1/1.8" = .555" (bigger than a .50 caliber bullet or ball)
8MP - 1/1.2" = .833" (bigger than a 20mm chain gun round)

And the chart above simply presents this graphically.

Sensor sizing can confuse a lot of people LOL.

It is simple division:

1 divided by 3 equals 0.333

1 divided by 2.8 equals 0.357

Is a 1/2.8" sensor bigger than a 1/1.8" sensor? Most people say yes LOL. But it is a fraction, so the 1/1.8" sensor is the bigger of the two. A 1/2.8" sensor is smaller than a 1/2.7" sensor.

 

[Frank888]

1 divided by 3 equals 0.333

1 divided by 2.8 equals 0.357

True, and this equals just a 7% increase in sensor size, while the amount of pixels increases by 200%. That means the pixels must be equally smaller, which usually leads to more noise because it "sees" less light.
But otherwise, the chart is a good reference for the sensor size/pixel ratio.

 

[Mike A.]

Also was a big jump in sensor design with the back-illuminated sensors coming in at around that 1/3-to-1/2.8 transition point. Size matters but it's not all size. But for security cams sensor design and the signal processing side have followed along that same progression so the chart still works for our purposes.

 

[sebastiantombs]

Overall, those numbers and relationships relate to real world experience by hundreds, if not thousands, of users experiences and are documented with video that includes clear night video with motion. The numbers don't lie but real world experience can show that the combinations being promoted here do produce the results needed for good night video that includes motion IF the camera is properly adjusted to accommodate the lighting conditions it is "seeing". No amount of adjusting for a 1/3" sensor with a 2MP resolution will result in good night video with motion.

 

[Mike A.]

Our standards for what's considered "good night video" also have changed. I thought that the 5231/2231s were awesome when they came out. And they were compared to what I had before. Still are very good. But they do show their age now compared to cams with the 1/1.8 and 1/1.2 sensors. I'm sure that standard will change again.

 

[sebastiantombs]

One of the other problems, that's never really mentioned, is the ambient light or lack thereof, in each individual case. I have a 3241 on the front of the house and it needs to switch into night mode just after sundown. A 3241 on the rear of the house can stay in color mode, with great motion video, well after sundown. The only difference is the amount of ambient light at those times getting into each scene. At the same time a number of the 5442 cameras have also been switched to night mode while that one 3241 is producing good color. It's all a matter of ambient scene lighting. Sure, there's a difference in resolution, but in terms of bang for the bucks the 3241 is still holding its' own.

 

[i6jm]

Thank you

According to your advice, these are the best bullet Camera models that can be purchased from Hikvision, right?

For 2MP

2CD2027G2-L

or

2CD2T27G2-L

--

For 4MP

2CD2047G2-L

or

2CD2T47G2-L

--

For 8MP

2CD2087G2-L

or

2CD2T87G2-L



And Does your advice include cameras that are not equipped with Colors Vu and contain only IR?

 

[Björn0815]

Hi folks , thanks for this nice chart DanDenver, but if I follow this table then somehow I can't find a camera (if possible Turret) with 8 MP and 1/1.2" (so in the green area) that is not "ColorVu" but simply with infrared or are there some and I haven't found them yet ?
I'm thinking about replacing several of my cameras because I unfortunately bought some that don't meet the requirements for very low light conditions at night.
Or do I still have to be satisfied with an 8 MP camera with a 1/1.8" sensor which, according to the table, is only in the yellow range?

Or do I even have to go back to 4 MP cameras because, as I have read, there is more choice of cameras where the ratio between MP and image sensor is better?

Thanks for any advice

 

[wittaj]

The 8MP on the 1/1.2" sensors are only full color type cameras and do not see infrared. Further people are seeing that these cameras show that these cameras are not infinity focus and have a very narrow focus range of 15-17 feet and anything shorter or longer than that will be blurry.

So most use the 1/1.2" sensor cameras as overview to get color even if it is a little blurry.

We are still seeing that between 8MP and 4MP both on the same 1/1.8" shutter that the 4MP version will perform better at night.

So if night performance is your criteria, stay with a camera in the green.

Many have found that 4MP is the sweet spot for surveillance. The proper focal length for the distance you want to IDENTIFY is much more important than MP.

The Importance of Focal Length over MP in camera selection

At the urging of several folks here, I created a thread to show the importance of focal length and how focal length can be more important than megapixels (MP). I mentioned some of this in the post regarding The Hookup’s latest video demonstrating different cameras, including one sold from a...

ipcamtalk.com

 

[Björn0815]

Thanks for your reply, I will check this article and I will probably end up going back to 4MP with the right sensor and adjusted focal length