What is the difference between a 6mm lens and a 3.6mm lens

Understanding security camera lenses enough to decide which is best for your surveillance security camera needs can be a confusing and overwhelming process. Lens descriptions such as fixed-lens, 2. See the Pictures. The trail has about 15 meters 1. Picture approx 2. Picture approx. Picture approx 6 mm 4. Picture about 12mm i am now happy Arjun said:. Except located close to a front door, 2. You want to know who did it, not just what happened.

This comes more into play after dark. MacFun Getting the hang of it. View attachment Ubaid-Dahua n3wb. Joined Jan 17, Messages 7, Reaction score 8, Ubaid-Dahua said:. Wondering what equation they are using. The DORI distance is calculated based on sensor specification and lab test result according to EN which defines the criteria for Detect, Observe, Recognize and Identify respectively.

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. Joined Aug 6, Messages 32 Reaction score 6. I'm going to buy one 2. I'm using 12 cameras total so I'll test each focal length and see which works best. Camera lenses are covered in all sorts of numbers designating things like focal length and aperture We are explaining lenses, what is focal distance and what is f stop.

We present few examples and sketches for an easy understanding of the photography terminology of focal distance, focal length, f stop, aperture, all related to camera lenses.

Macro Photography on a Budget. Pringles-can lens extender produces dazzling ultra close-ups for peanuts. Bokeh on a budget - kit lens demo. I will expand on this a little later. Ok — back to the focal length of a surveillance camera. The focal length is the gap between the image sensor and the lens.

This is the distance between the lens and the image that is required for a particular lens to produce a sharp image.

You will see an image that is out of focus if the distance between the image sensor and the lens is not exactly right. There are an almost infinite number of different possible lens combinations, however they are broken down into 2 sub categories. These are lenses that have 1 fixed focal length setting. They have no adjustment. You get what you are given. You can not adjust them. If the focal length is not suitable, then tough.

There are many different fixed lens options, however the most common one is a 3. This will allow you to identify people at around 20 feet. We also stock a smaller range of other fixed lens CCTV cameras. The 8mm Lens.