Any
camera that can do this with a 2.8 mm lens/no zoom?
Nice to haves:
Varfocil.
PTZ.
Also two other related questions:
1. Any info on why IP cameras are so far behind the curve when it comes to using the latest image sensor tech?
2. I noticed the below image, is this tool available somewhere?
www.ipcamtalk.com
I've not used that metric before, but after a little research it seems 60-80 ppf is a target number.
A little background, my usecase is not for automation of tag reading, just want to be able to make out tags in off chance its needed.
Hi
@aspir_mhi
Do remember to check out the
cliff notes and the DORI section in there as well as the IPVM calculator ( which I think you may have already seen it.. )
Also, this would be a good thread to go over with regards to your question
Q: 1. Any info on why IP cameras are so far behind the curve when it comes to using the latest image sensor tech?
thread to check out:
Expecting to much
Ok, now to your main question
Given requirements:
- Reading vehicle tag at night at 200 ft
- camera that can do this with a 2.8 mm lens/no zoom
- 60-80 ppf
Thanks, makes it clear you are looking to capture the license plate and not the tiny tag on the corner of US plates.
OK, let's start with some math on this one and see what we need.
Here's some data which I've posted before, and with the info in the Cliff Notes can be calculated.
( this is the theoretical ID range, that is to the 100 ppf mark - we're assuming we have effective resolutions .. )
Dahua IPC-HDW4231EM-AS starlight fixed lens 1080p 1920x1080 ( it is a 2MP camera )
w/2.8mm lens FOV H 110 degrees: 10 feet { area covered 95.94 sq feet covered }
w/3.6mm lens FOV H 87 degrees: 12.65 feet { 121.43 sq feet covered }
w/6mm lens FOV H 51 degrees: 21.58 feet { 207.16 sq feet covered }
So you want to know about 60 ppf. Ok 100 / 60 = 1.6667
Thus using 2.8mm lens, 10 feet x 1.6667 = 16.67 feet to the 60 ppf mark.
OK, assuming the same aspect ratio let's figure out what you need.
you want 60 ppf at 200 feet, so 200 feet / 16.67 feet = 12 ( i.e. 16.67 goes about 12x into 200 )
Thus you need 12x the H FOV resolution. ( 1980P ) = 23,040 pixels on the Horizontal ( i.e. H FOV )
The same aspect ratio -> also means 12x the V FOV ( 1080P ) = 12,960 pixels on the Vertical ( i.e. V FOV )
So, the question - what resolution camera do we need ( of the same aspect ratio ) for this
298,598,400 pixels, or about
300MP ( a bit less.. )
SO you want to find a 300MP camera with an equivalent angle as the sample 2.8mm lens 2MP starlight model
Oh, and this only applies for daytime images.. as typically during night time you have less effective pixel capture.
