The Importance of Focal Length over MP in camera selection

[wittaj]

@wittaj sounds like you have more than 1 camera mounted on each corner of the premises, one dedicated to "identify" and other for "observe"

That is correct. I slowly learned the "one camera on each corner of a square house and I can see everything" concept means you can only tell the police what time something happened and not much else.

The 180 cameras did allow me to remove some cameras...ok let's be real I repurposed them to another part of the house LOL...but the 180s in default mode make great overview cameras to be able to see what is going on, but you need other cameras set up to do the IDENTIFY.

 

[Arjun]

That is correct. I slowly learned the "one camera on each corner of a square house and I can see everything" concept means you can only tell the police what time something happened and not much else.

The 180 cameras did allow me to remove some cameras...ok let's be real I repurposed them to another part of the house LOL...but the 180s in default mode make great overview cameras to be able to see what is going on, but you need other cameras set up to do the IDENTIFY.

Good, at least I'm not the only crazy one putting more than one camera on each corner One camera even doubles as an LPR camera; I also have one varifocal turret that is tightly optimized to work 24/7 doing both Observe and Identification when the LPR is exclusively focused on LPR at night
I had to go through many hoops with myself when it came to camera locations

 

[David L]

I was looking at the 180, but for a little more I got two 5442 S3s which will over lap each other in view...one on each end...
I know there is more to this with one being IR and the other not but for me the two CAMs will work good.

 

[Arjun]

I was looking at the 180, but for a little more I got two 5442 S3s which will over lap each other in view...one on each end...
I know there is more to this with one being IR and the other not but for me the two CAMs will work good.
View attachment 239915

Two is always better than one, especially if one of the two goes bad. The T180 is notorious for not being waterproofed adequately; past complaints of water getting inside the lens - not good, needs more testing

 

[not_elvis]

Hi, I am looking for some guidance when it comes to choosing focal length. Our apartment has an entrance door to the outside (not a communal entrance) and a terrace. For my wife's peace of mind, I would like to install a camera to keep an eye on these two areas, especially as they are hidden from view from the street.

The entrance door is slightly recessed, opening to a rectangular space leading to the outside stairs. There is a light which I linked to motion sensors - one further down the stairs, one next to the entrance.

Overall space is maybe 3 x 4 meters. The camera would most likely have to be installed somewhere close to where I attached one for trials here:



The view from the camera would be something like this:



The terrace is a bit larger, maybe 4 x 5 meters, framed by hedges - but with access to the stairs. The best position for the camera should be somewhere close the door where I marked it with a red arrow - but the height could be adapted:



The view from the camera would be something like this:



There is no light on the terrace, and I would like to avoid light in the visible spectrum that could disturb the neighbors.

Given the spaces, I think I need:

• A relatively wide angle
• Not too much zoom as distances are limited
• A camera still able to focus on fairly close-by subjects
• IR LEDs for the terrace

Does this make sense? I have an Annke NC800 which I ordered without too much research because of its supposed low-light capabilities. I am wondering if it would be a good fit for the entrance where it would benefit from the lamp. It has a rather wide angle lens - 2.8mm I think.

For downstairs, I was considering a reasonably priced Dahua IPC-HDW5442TM-ASE-S3 which I found on a classifieds site. 2.8mm lens, IR LEDs.

Am I on a good path here or do I misjudge the requirements for my spaces? I would like to see if there is someone in those two spaces, know what they are doing, and ideally have a good enough picture to ID them if ever there was a break-in and they were stupid enough not to cover their faces.

Oh, and what installation height is best for this? If it is too high, faces will be captured from a less useful angle, I guess?

 

[Chokolinho]

Hi, I am looking for some guidance when it comes to choosing focal length. Our apartment has an entrance door to the outside (not a communal entrance) and a terrace. For my wife's peace of mind, I would like to install a camera to keep an eye on these two areas, especially as they are hidden from view from the street.

The entrance door is slightly recessed, opening to a rectangular space leading to the outside stairs. There is a light which I linked to motion sensors - one further down the stairs, one next to the entrance.

Overall space is maybe 3 x 4 meters. The camera would most likely have to be installed somewhere close to where I attached one for trials here:

View attachment 242941 View attachment 242942

The view from the camera would be something like this:

View attachment 242943

The terrace is a bit larger, maybe 4 x 5 meters, framed by hedges - but with access to the stairs. The best position for the camera should be somewhere close the door where I marked it with a red arrow - but the height could be adapted:

View attachment 242945

The view from the camera would be something like this:

View attachment 242946

There is no light on the terrace, and I would like to avoid light in the visible spectrum that could disturb the neighbors.

Given the spaces, I think I need:

• A relatively wide angle
• Not too much zoom as distances are limited
• A camera still able to focus on fairly close-by subjects
• IR LEDs for the terrace

Does this make sense? I have an Annke NC800 which I ordered without too much research because of its supposed low-light capabilities. I am wondering if it would be a good fit for the entrance where it would benefit from the lamp. It has a rather wide angle lens - 2.8mm I think.

For downstairs, I was considering a reasonably priced Dahua IPC-HDW5442TM-ASE-S3 which I found on a classifieds site. 2.8mm lens, IR LEDs.

Am I on a good path here or do I misjudge the requirements for my spaces? I would like to see if there is someone in those two spaces, know what they are doing, and ideally have a good enough picture to ID them if ever there was a break-in and they were stupid enough not to cover their faces.

Oh, and what installation height is best for this? If it is too high, faces will be captured from a less useful angle, I guess?

If I were you, I’d go with the 5442-ASE-S3 for the front door in 3.6 mm. For the garden, I’d go with the Tioc Pro. According to my information, the NC800 only has white light and no IR.

 

[bigredfish]

^^^^^
This both 3.6mm

 

[not_elvis]

If I were you, I’d go with the 5442-ASE-S3 for the front door in 3.6 mm. For the garden, I’d go with the Tioc Pro. According to my information, the NC800 only has white light and no IR.

Thank you! Correct, the NC800 has only visible spectrum/white light. That is why I was considering it for the main entrance where there is a lamp anyway.

Do you recommend 3.6mm over 2.8mm because the angle of view would still be wide enough for my use case or is there another reason?

The Tioc Pro is a bit above my price range. I found a SD3E405DB-GNY-A-PV1 on the local classifieds site, and it is more or less within my budget. Could that be a good fit? It has a 2.7 mm–13.5 mm zoom though, which seems like a lot more than I need.

 

[David L]

^^^ Focus Distance is often missed. I have a couple of 6mm but the cameras are set back enough where the 10 feet focus works in my case. There is not much difference between 2.8 and 3.6 in focus or Identify (DORI) which is what you would want.

EmpireTech IPC-T54IR-AS-S3 1/1.8" CMOS 4MP IR Fixed-focal Turret Netwo

1/1.8" CMOS image sensor Built-in IR LED, Max. illumination distance is 50 m Deep learning algorithm Supports max. 512 GB Micro SD card Built-in MIC IP67 protection Smart Motion Detection 3.0

empiretech01.com

 

[not_elvis]

^^^ Focus Distance is often missed. I have a couple of 6mm but the cameras are set back enough where the 10 feet focus works in my case. There is not much difference between 2.8 and 3.6 in focus or Identify (DORI) which is what you would want.

Thank you. 10 ft would make much of my area under surveillance out of focus. The 4.3-4.9 ft of 2.8/3.6mm seem more useful, and even then anyone directly at the doors would probably be out of focus.

I was wondering why @Chokolinho and @bigredfish felt strongly that 3.6mm was to be preferred over 2.8mm in my use case. Even more so as 3.6mm seems harder to source, at least in Europe. It is mostly sold out, whereas I can find 2.8mm cameras.

 

[David L]

Thank you. 10 ft would make much of my area under surveillance out of focus. The 4.3-4.9 ft of 2.8/3.6mm seem more useful, and even then anyone directly at the doors would probably be out of focus.

I was wondering why @Chokolinho and @bigredfish felt strongly that 3.6mm was to be preferred over 2.8mm in my use case. Even more so as 3.6mm seems harder to source, at least in Europe. It is mostly sold out, whereas I can find 2.8mm cameras.

FOV is why, for narrow areas like yours the 3.6mm would be recommended. It actually would make things look bigger/taller too which would be good for Identifying...2.8 is popular for it's wide view. I have several CAMs but like the 3.6mm best.

 

[David L]

Here is a picture of my 3.6mm 5442 Series 1 CAM of our backyard from our old house...it was mount under eave, so 10 feet high...it was the perfect FOV for that area.

 

[David L]

Here is our Front yard 2.8mm 5442 Series 1 CAM, same old house...this one is mounted 8 feet high under eave

 

[not_elvis]

If I were you, I’d go with the 5442-ASE-S3 for the front door in 3.6 mm. For the garden, I’d go with the Tioc Pro. According to my information, the NC800 only has white light and no IR.

For the garden, I don't want white light in order not to bother the neighbors. At least not permanently - maybe an object detection in Frigate could trigger switching on the white light? But I am wondering if a pure-IR 5442 wouldn't be good here too.

FOV is why, for narrow areas like yours the 3.6mm would be recommended. It actually would make things look bigger/taller too which would be good for Identifying...2.8 is popular for it's wide view. I have several CAMs but like the 3.6mm best.

Ah, okay. I considered the area narrow in absolute terms, but in terms of viewing angle relatively wide as it is not too far from a square base shape - rather than one long and narrow corridor. Thanks for the picture.

 

[David L]

Thank you. 10 ft would make much of my area under surveillance out of focus. The 4.3-4.9 ft of 2.8/3.6mm seem more useful, and even then anyone directly at the doors would probably be out of focus.

I was wondering why @Chokolinho and @bigredfish felt strongly that 3.6mm was to be preferred over 2.8mm in my use case. Even more so as 3.6mm seems harder to source, at least in Europe. It is mostly sold out, whereas I can find 2.8mm cameras.

Also, try not to mount it too high, that backyard CAM @ 10 feet got alot of tops of people's heads, best height would be eye level but I would not go over 8 feet high...

 

[Chokolinho]

For the garden, I don't want white light in order not to bother the neighbors. At least not permanently - maybe an object detection in Frigate could trigger switching on the white light? But I am wondering if a pure-IR 5442 wouldn't be good here too.



Ah, okay. I considered the area narrow in absolute terms, but in terms of viewing angle relatively wide as it is not too far from a square base shape - rather than one long and narrow corridor. Thanks for the picture.

Then the Tioc would be perfect for you. You can set it to infrared mode, and as soon as someone enters the ivs areas in the garden, it switches to white light.

 

[David L]

For the garden, I don't want white light in order not to bother the neighbors. At least not permanently - maybe an object detection in Frigate could trigger switching on the white light? But I am wondering if a pure-IR 5442 wouldn't be good here too.



Ah, okay. I considered the area narrow in absolute terms, but in terms of viewing angle relatively wide as it is not too far from a square base shape - rather than one long and narrow corridor. Thanks for the picture.

Here is a good tool to help you see placement...

Lens Calculator

www.jvsg.com

Even has German language...

What is nice about this tool is you can set camera height...which helps...