Minimum PPF Recommendations? >100 Or?

john-ipvm

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I have noticed that a number of members here recommend minimum PPF recommendations of 100+ I am curious what others recommend?

The upside of 100+ ppf is that it gives a significant margin of error for harsh lighting or low light or poor lens quality, etc. The downside is that it forces constraints in horizontal FoV, e.g., 1080p at 100+ ppf is ~20' max, 4MP at 100+ ppf is ~27' max. In smaller indoor areas, that can often work but larger areas, longer hallways and outdoor areas can be pretty difficult to meet 100+ ppf.

As a point of reference, for the ~150,000 cameras saved in the IPVM calculator, the average is ~60 ppf. I am not saying any one value is 'right' but in practice it seems that ppf is often sacrificed given constraints on coverage width, camera count, etc.

So curious what PPF targets you aim for? And also how often, or ever, you go below those targets?
 

zero-degrees

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I find 75 PPF to be sufficient in most active monitoring applications and as low as 50 in passive monitoring situations.
 

SyconsciousAu

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That entirely depends on what I am trying to achieve.

On all of my ID cameras I aim for better than 420ppm (126ppf), which is the standard recommended by the Australian and New Zealand Policing Advisory Agency and is 120% of the 352ppm (106ppf) identification standard set out in Australian Standard AS 4806.2 – 2006. Usually these are placed on choke point's like gates, doors, side passages, or high value areas like letter boxes.

Pixels per metre standards.png

This is a table of the Australian Standards.

For the most part I like to maintain better than 176ppm (53ppf) in all other areas with the exception of no value areas like the compost heap in the back corner of the yard.

In the days of cheap megapixel cameras with zoom lenses there is very little excuse for not achieving good pixel density in a large number of areas. I find that by installing camera's in pairs with interlocking fields of view, the best of both worlds can be achieved.
 
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