- 1 What is a varifocal CCTV camera?
- 2 What is varifocal zoom?
- 3 What is the difference between varifocal and fixed lens CCTV?
- 4 What is motorized varifocal lens?
- 5 What is the purpose of a varifocal lens?
- 6 What are Varifocals used for?
- 7 Does zoom affect focus?
- 8 Why is zoom out of focus?
- 9 How far can a 12mm lens see?
- 10 What angle is a 2.8 mm lens?
- 11 What is the difference between 2.8 mm and 3.6 mm lens?
- 12 What does WDR mean on a camera?
- 13 What does motorized camera mean?
- 14 Is zoom a lens?
- 15 What are varifocal contact lenses?
What is a varifocal CCTV camera?
Varifocal lens security cameras are security cameras with lenses where you can adjust the zoom so that you can focus on objects that are close or far away. Some varifocal lenses change focus automatically, responding to the motion and images that are within their view.
What is varifocal zoom?
A varifocal lens is a camera lens with variable focal length in which focus changes as focal length (and magnification) changes, as compared to parfocal (“true”) zoom lens, which remains in focus as the lens zooms (focal length and magnification change).
What is the difference between varifocal and fixed lens CCTV?
What’s the difference between varifocal and fixed lens CCTV? In short, fixed lens cameras give a specific field of view, while the viewing angle of a varifocal is set during installation. The moving parts and lens adjustment required for varifocals increases the price of a camera.
What is motorized varifocal lens?
Compared with the conventional manual vari-focal lens, a camera has the motorized zoom lens can automatically adjust the focal length of camera to get clear auto focused image. This makes security camera installation become much quicker and easier.
What is the purpose of a varifocal lens?
Varifocal lenses are a common type of corrective lens that were first invented in 1959 by ourselves. Generally speaking, they are designed to let you see clearly at near to far and everything in between, with different parts of the lens optimised for the various distances required.
What are Varifocals used for?
Varifocal lenses allow you to see at any distance, because they have different sections for viewing close up and far away and everything in between. So whether you’re driving, using a computer, shopping or reading, you can wear one pair of varifocals to accommodate all your vision needs.
Does zoom affect focus?
The technique of zooming in to check focus and then zooming back out to the desired focal length is common in the video industry, where lenses do tend to maintain the same focus distance across the zoom range. In the still photography world, however, lenses may shift the focus distance as you zoom in and out.
Why is zoom out of focus?
Some zoom lenses that are not really parfocal, particularly those with smaller maximum apertures, can appear to act like they are parfocal if the focusing error introduced by zooming is less than the depth of field at the lens’ widest aperture.
How far can a 12mm lens see?
At 12mm you will achieve around a 30° angle of view and identification at around 50 feet. The real trick is that this lens can be set to anywhere between those two different focal lengths.
What angle is a 2.8 mm lens?
2.8mm for a 90° view With a wide field of view, the 2.8mm lens is a popular choice for static camera surveillance. It can cover a wide area with just one camera.
What is the difference between 2.8 mm and 3.6 mm lens?
A 3.6mm lens is designed to provide an approximate 78° field of view and is the perfect camera in most CCTV applications. Most people think that a 3.6mm lens won’t show a large field of view, but as you can see from the below images, there’s not a huge difference between a 2.8mm and 3.6mm lens.
What does WDR mean on a camera?
On a sunny day, however, in a scene with distinct shadows, there will be a greater difference between the brightest and darkest areas, and this is what we call a wide dynamic range or WDR (also known as High Dynamic Range, or HDR). Figure 1: An IP camera without WDR capability.
What does motorized camera mean?
These lenses are designed for integration into bullet and dome cameras. The focus and zoom motors allow user control of the focus and zoom functions remotely without direct handling of the lens itself.
Is zoom a lens?
A zoom lens is a type of camera lens that offers the photographer a useful range of different focal lengths in a single lens. This is in comparison to a prime lens, which only offers a single focal length. A zoom lens allows for quick and easy re-framing of a scene while staying in the same physical position.
What are varifocal contact lenses?
Also known as multifocal contacts, varifocal contact lenses accommodate multiple vision types into one little lens. So you can see in all situations without the need for additional glasses.