Are Longer Lenses Better For Security Investigations Or Will Wider Angles Do?
Are Longer Lenses Better For Security Investigations – Does SEN think most applications should feature a much smaller angle of view than we typically see and more use of cameras with overlapping fields of view?
A: If money was no object, you’d opt for multiple cameras with longer focal lengths that gave sufficient coverage of a scene. That said, you’d still want a wider angle of view specifically to give situational awareness so as to highlight the way people and objects are interacting.
There are applications in which those landscape-style, 120-degree-plus fields of view are ideal – lobbies, public transport, foyers, meeting rooms. But 120-degrees-plus doesn’t translate as well into deeper scenes unless situational awareness is all you want.
With wide angles, a covered space needs to be compact, and applications should be tested to ensure a particular camera and lens meet a particular operational requirement. While the tiny hyperfocal distance of wide-angle lenses keeps everything in focus optically, pixel spread means resolution is spread very thin.
In good light, wide angle lenses work better with larger sensors that have more pixels, yet in these penny-pinching times they are too often found on cameras with the smallest and least expensive sensors that try to do everything but do nothing well.
In short, resolution is important, and you can gain resolution by reducing angle of view. You also flatten the image and reduce areas of softness induced by extreme lens profiles. Perspective is altered with wide angle lenses, too. Objects can appear further apart than they are.
We’d argue sharpness is the key for security investigators, day or night. A soft, low-resolution image is no use for video surveillance teams unless it’s verifying alarm events and/or governing real time response teams.
You can learn more about the challenges of using wide angle lenses here – yes it’s photography but much translates – or find more SEN news here.
“Are Longer Lenses Better For Security Investigations Or Will Wider Angles Do?”
