Suggestions for night vision IQ increase

[BigCarbs 0]

Ok so I have some of the Hikvision 3mp bullets covering the front yard. I want to setup another camera or two specifically for getting a better look at people in front of my house. In the video There are two people that I am lead to believe were going to attempt to break into a neighboring home. Only problem is you can't get a positive ID. So I am looking for suggestions of perhaps getting another camera, varifocal or perhaps 8-12mm range and focusing on the street. the motion at night is also a bit bad as far as sometimes leaving trails and such. Even if i dont get a whole lot of field of view but If I could get facial recognition and perhaps daytime license plates would be great. Considered one mini PTZ tucked up there but may be too bulcky

 

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[buellwinkle 0]

The rule of thumb is you need a persons face to be at least 85 pixels tall to be identifiable and a license plate should have numbers about 12-15 pixels tall. You can use your existing image as a guide to see how many pixels tall those people's faces are. For example, if they are say 30 pixels tall, then you need 3x the focal length, so in your case, if that's a 4mm bullet, you'll need 12mm. Of course, the downside is 1/3 the field of view. Varifocals are like manual zooms, not like zoom camera. Meaning you have to take the camera apart to reach the zoom and focus controls. It's great if you don't know what field of view you want or a custom field of view, but you actually get a sharper image from your Hik bullet than you will from a Hik varifocal bullet. Having said that, I use the Hik varifocal dome a lot because it's a good camera and I can adjust the field of view at install time, no guessing.

 

To measure how many pixels a persons face is I use Photoshop ruler tool, but if you don't have Photoshop, maybe some open source photo editing software can help. For me, with 3MP and 4mm, I can ID someone as far as 20-25', so you can also use that as a rough guide.

 

What security people do is have an overview shot as you show, perfect, then have a telephoto camera at what's called a choke point, an area a thief would have to go past to get to you, like alleyway, doorway, side gate. It's hard when you want to do security for everyone, but you could put a 12mm bullet in the middle of the street and hope the suspect walks past that point.

 

What one person here has done is put 3 cameras together with telephoto lenses to get wide coverage, in effect having 9MP. Each camera pointed edge to edge to provide a single wide field of view.

 

To PTZ or not to PTZ. PTZ is great when you have a full time security guard and he can zoom in on a suspect. In real life for a home, no security guard, the best you can do is put the cameras on patrol, but each patrol point splits the time your cameras sees an area, so 4 points means the camera sees one point 1/4th the time, leaving the area unprotected 3/4 of the time. I love PTZ as webcams, but for security, not sure of their value. They have higher end PTZ with auto-tracking, but not sure the tech lives up to the hype, but certainly a fun toy to have. Then the cost, maybe $600-800 vs. having 3-4 times the number of fixed cameras.

[BigCarbs 0]

Many good points above.

At 20-25' can you id at night with the noise in the image? Somebody commented the video that the bitrate seems too low as far as the quality. It seems that no matter night mode or leaving in color that when its night time i get much worse quality. If people walk by in blue jeans its like the camera doesnt pic up their pants and they blend with the road.

 

I like the idea of multiple telephoto cameras but then neighbors would definitely start talking

[MaxIcon 0]

To measure how many pixels a persons face is I use Photoshop ruler tool, but if you don't have Photoshop, maybe some open source photo editing software can help. For me, with 3MP and 4mm, I can ID someone as far as 20-25', so you can also use that as a rough guide.

An easy way to measure this is to use the cam's web interface to save a screen shot, and open that up in MS Paint (assuming you're using Windows). Click the select tool and draw a rectangle around the object, and it'll show you how many pixels it is on the bottom of the screen.

 

Many good points above.

At 20-25' can you id at night with the noise in the image? Somebody commented the video that the bitrate seems too low as far as the quality. It seems that no matter night mode or leaving in color that when its night time i get much worse quality. If people walk by in blue jeans its like the camera doesnt pic up their pants and they blend with the road.

 

I like the idea of multiple telephoto cameras but then neighbors would definitely start talking

 

ID'ing people at night is tricky. Too far and the noise and low contrast obscures them, too close and they get washed out by the IR, unless you have smart IR. Longer exposure times help with IQ but give motion blur. Night mode loses a lot of contrast due to the BW image. Color's better, but needs more white light. A faster cam (1/2" sensor and fast lens) can help, but costs a lot more.

 

The best affordable solution is better lighting, but that, along with the multiple cams you'll end up with, will definitely have the neighbors talking!