Your Los Angeles Family
Whether you’re looking to check up on the babysitter, check in on your grandparents, keep up with your kids or just keep them close, our security cameras with Total Connect puts peace of mind in the palm of your hand.
Surveillance Systems starting at $499
But when protecting your family we will help you select the right surveillance system to meet your specific needs, some of the factors to be considered are:
I. Introduction to lensing
A. Initial questions concerning the system you are buying and installing
II. Lens terminology
A. Focal length of cameras
1.
Fixed focal length2. Variable focal length
B. F-stop
1. Aperture
C. Depth of field
III. Effects of lighting
•A. Auto iris lenses
B. Electronically shuttered cameras
IV. Mounts and formats
A. C/CS
B. Image formats
C. Combining unlike formats
V. Lens selection
A. Calculation
B. Tables
C. Wheels
D. View finder
Question and answers
Since the introduction of electronically shuttered cameras there has been discussions concerning where these type of home security cameras can effectively be used. Questions most often asked are:
• How close are they in performance to an auto iris lens?
• How much light can these cameras tolerate?
• Can they be used outdoors?
Auto-shuttered cameras have the ability to vary shutter speed in accordance with the intensity of light. Our home Security Cameras Shutter speed increases with brighter lighting thereby lowering the video input level. The camera will work similarly to an auto iris lens. The greater the quantity of shutter speeds the less likely the camera will "jump" between steps.
Also the faster the shutter can operate the greater the light range the camera and lens can effectively perform
within (i.e. a home security camera which can step to 1/10,000 sec. will not perform as well as one which goes to 1/20,000 sec.).
Because of the extreme sensitivity of CCD's on the market today, there are limits as to how much light they tolerate. In the chart below we see that if a lens is set at f 1.2 the shuttered camera is effective from 0.3 lux to only 16,000 lux. We can extend this range by closing down the iris, but you will lose some of the security cameras low light capability. In the brightest condition outdoors light can get as bright as 200,000 lux (full daylight in good weather measures about 85,000 lux). This can pose a serious problem!
An auto iris lens with an average spot filter will reduce the intensity of light reaching the chip. In fact, even under the brightest conditions, an auto iris lens will reduce the light to a manageable level for most chip security cameras. 200,000 lux will change into approximately 26 lux. With an auto iris lens you can get the best-low light capability without sacrificing the home security camera's ability to operate in full or direct lighting conditions. In short an auto iris lens
