Megapiksel ve HD IP kameralar Analog kameralarla karşılaştırıldıklarında, yatayda yaklaşık 2,5 ila 10 kat fazla görüş alanı sağlamaktadır. Bu nedenlerle HD kameralar özellikle normalde birden çok analog kamera kullanılarak kontrol altına alınabilecek geniş alanların izlenmesinde büyük avantaj sağlamaktadır. Örneğin açık/kapalı otoparklar, trafo merkezleri, havaalanları, kütüphaneler, lobiler, alışveriş merkezleri, süpermarketler, depolar, tren istasyonları gibi geniş alanlar HD çözünürlüğe sahip az sayıda kamera ile ölü nokta kalmayacak biçimde izlenebilmektedir. ...[More]

It's an exciting time in the security department. You've finally received approval to migrate from your installed analog cameras to new megapixel models and expectations are high. As you get together with your integrator, you start selecting the cameras you plan to install, looking forward to getting higher quality, higher resolution images and, in many cases, covering the same amount of ground with one camera that, otherwise, would have taken several analog models. You're covering the basics of those megapixel cameras, including the housing and mounting hardware. What about the lens?

You've just opened Pandora's box....[More]

Also translated into Russian
Что такое мегапиксельный объектив и для чего он нужен

The detail in an image is determined by resolution. The shorter the lens focal length, the wider the field of view. Greater than about 90° most lenses start to show curved, barrel distorted images that compress the image at the edges. Rectilinear lenses such as those using Theia Technologies' Linear Optical Technology™ don't exhibit barrel distortion and thus maintain image resolution out to the edge of the image.

Resolution has many definitions; no one definition is correct for all situations. Resolution can be specified in pixels per foot or meter at the object. This mapping of the image sensor dimensions onto the object is most intuitive for calculating what level of detail can be seen in the image. Fundamentally it is the horizontal field of view of the camera divided by the horizontal number of pixels. This gives a pixels per foot number that can be related to image quality. ...[More]

Mere mortals see only visible light, whereas security cameras can see both visible and infrared (IR) light. Many light sources including the sun create both visible and IR light. Security cameras use color filters (blue, green, and red) to create a color image but each filter also allows IR light to pass through onto the sensor, muddying the colors. Since most lenses are designed for visible light only, most security cameras have an IR filter to block the IR light. This filter improves both the color fidelity and focus sharpness of the image.

But those cameras considered true day/night can physically switch the IR filter out of the light path allowing the camera to see both naturally occurring and artificially created IR light. These cameras require day/night lenses to keep the scene in focus both day and night. Day/night lenses are generally more expensive because of the added complexity of focusing a broader color spectrum (from visible through IR) onto the sensor....[More]

Arecont Vision and Theia have delivered an undistorted, detailed view of a Salem, N.J. high school's hexagonal hallway. The megapixel cameras by Arecont, and the wide angle lenses by Theia provide school administrators with a clear view of the school's three wings.

...The solution came by combining megapixel cameras from Arecont Vision with wide-angle lenses from Theia Technologies. Merging the capabilities of both technologies enabled the high school to significantly reduce the number of cameras it needed, and to get superior images in the process....[More]

Today’s megapixel cameras have many advantages as long as you have the right lens for the job. When that includes covering large areas or reducing cost by installing fewer cameras, that lens is a wide angle lens. Until recently only fisheye lenses were available for an ultra wide field of view. Fisheye lenses create a curved and distorted image which no one seems to like. This significant distortion causes loss of resolution at the image edges.

In the past year a new rectilinear lens giving a different ultra wide view without the barrel distortion or loss of edge resolution of fisheye lenses has been developed. This report is an overview of wide angle lens technology and how we overcome fisheye distortion using Linear Optical Technology....[More]

...Despite the limited budgets of so many state and local governments across the country, communities are finding ways to upgrade their security systems and use the latest technology to support their security plans. Upgrading to security systems using megapixel IP cameras with ultra wide angle lenses can be cost effective by reducing the number of cameras to be installed and maintained and eliminating cabling and DVRs without sacrificing video surveillance area.

One example is the Murrieta Valley Unified School District. At one of the district’s high schools a security system upgrade will remove all 170 existing analog cameras and replace them with just 43 IQeye megapixel cameras with ultra wide angle lenses from Theia Technologies....[More]

...In 2006 Gohman and Peterson obtained an exclusive license from InFocus to take the lens technology into other markets. They founded Theia Technologies and decided to enter the security and military markets initially.

Theia Technologies was started along with Japanese manufacturing partner Nittoh Kogaku KK. Nittoh Kogaku is a well respected lens manufacturer with plants in Japan and Indonesia...

Theia Technologies has introduced the world's first ultra wide rectilinear lens for the security and machine vision markets. Theia's proprietary Linear Optical Technology allows the design of ultra wide angle lenses with fields of view of up to 135° while almost completely eliminating barrel image distortion. Straight lines remain straight in the image. Distortion correction is achieved optically in the lens; no additional de-warping software is required, allowing...[More]