I prefer whatever one gets the FOV required for that particular application. It's not a matter of personal preference between one or the other.
Except located close to a front door, 2.8mm is almost worthless outdoors.Thanks,
What do most installers default to? It seems the field of view varies between 81 degrees and 110 degrees, which is quite significant.
In which locations would the 2.8mm and 3.6mm's be better applicable to?
Correct if you are installing a camera for security. I have a few 2.8 mm cams for overview and am happy with them. But i absolutely don't expect to identify someone i don't know with them.Except located close to a front door, 2.8mm is almost worthless outdoors.
You want to know who did it, not just what happened. This comes more into play after dark.
The Dahua Starlight Varifocal Turret (IPC-HDW5231R-Z) is really the best of the best and will fit most consumers home setups.
Learn how to use this: Camera Calculator / Design Software keep PPF>100, tutorial upper left. It will give you an idea of the lens you need.2.8mm vs 3.6mm, which do you prefer for a fixed-lens?
I like the way your 2.8 looks. I get your point about a tighter shot ( longer lens ) would get just the porch and better assist in identifying someone you don't know. Obviously, most newbies have cam that're far to wide for their application. Like the NestCams of the world—the FOV is too wide. At first glance it seems great until you are trying to ID someone 50 feet away.For example, here's what a 2.8mm looks like on my front porch. It was the first camera I bought, and totally the wrong lens size for my porch.
Notice how wide the FOV is. So instead of being the porch cam, it's the porch/yard/driveway cam, at the expense of when people walk up to the front door, this camera catches less detail of them than if I had used a bigger mm lens here.
A 6mm lens here would probably narrow the FOV to where only the porch is in the shot... and it would increase the detail on the people who walk up to the front door.
I will replace this camera eventually with a varifocal, so I can zoom it precisely to how I want the FOV to be. Maybe I want a little bit of the sidewalk from the driveway in the FOV. Or maybe not, maybe I want to zoom the FOV in even tighter, focusing more on the front door. That's what's great about varifocals. You're not stuck with just one FOV and can adjust as you figure out what shot works best for you.
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hmmm.. looks like Dahua is not using 100ppf to calculate the DORI identify distance. Wondering what equation they are using.
Don't have time to look this up more at the moment, but Googling the first part of it came back with a blurb on one of their product pages.hmmm.. looks like Dahua is not using 100ppf to calculate the DORI identify distance. Wondering what equation they are using.
EPC230U | Dahua Technology - Dahua TechnologyThe DORI distance is calculated based on sensor specification and lab test result according to EN 62676-4 which defines the criteria for Detect, Observe, Recognize and Identify respectively.
LOL I saw that also when I searched!Don't have time to look this up more at the moment, but Googling the first part of it came back with a blurb on one of their product pages.
EPC230U | Dahua Technology - Dahua Technology
For example, here's what a 2.8mm looks like on my front porch. It was the first camera I bought, and totally the wrong lens size for my porch.
Notice how wide the FOV is. So instead of being the porch cam, it's the porch/yard/driveway cam, at the expense of when people walk up to the front door, this camera catches less detail of them than if I had used a bigger mm lens here.
A 6mm lens here would probably narrow the FOV to where only the porch is in the shot... and it would increase the detail on the people who walk up to the front door.
I will replace this camera eventually with a varifocal, so I can zoom it precisely to how I want the FOV to be. Maybe I want a little bit of the sidewalk from the driveway in the FOV. Or maybe not, maybe I want to zoom the FOV in even tighter, focusing more on the front door. That's what's great about varifocals. You're not stuck with just one FOV and can adjust as you figure out what shot works best for you.
View attachment 20951