How is it possible for the ¼” CCD to have more “effective pixels” than the larger 1/3” CCD camera. Here are the two cameras I am looking at:
Camera Specifications Model GW648W
Image Sensor 1/3" SONY CCD
Effective Pixel NTSC: 768(H)x494(V)
Sensor area 4.9mm x 3.7mm
Horizontal Resolution 540TV Lines
Minimum Illumination 0.0 Lux (IR LED ON)
Electronic shutter Auto: 1/50(1/60) ~ 1/100,000Sec
S/N Ratio >48dB
Gamma 0.45
Lens 3.6mm
Video Output 1. 0Vp - p, 75Ω
IR wave length 850nm
Power supply DC12V±10%
Power consumption IR Distance
20M (65.6 ft with 24 Unit infrared LED)
Camera Specifications Model GW648
Image Sensor 1/4" SONY CCD
Effective Pixel NTSC: 811(H)x508(V)
Horizontal Resolution 540TV Lines
S/N Ratio >48dB
Clock Frequency (MHz) NTSC: 19.0699
Scanning System 2:1 Interlace
Minimum Illumination 0.0 Lux (IR LED ON)
Synchronous System Internal, Negative sync.
Auto Electronic Shutter NTSC: 1/60s~1/100,000s
Gamma 0.45
IR Distance 20M (65.6 ft with 24 Unit infrared LED)
IR Status Under 10 Lux by CDS
IR Power On CDS Auto Control
Video Output
1. 0Vp - p, 75Ω
Auto Gain Control Auto
Power/Current DC12V±10%/500mA
Lens 3.6mm
Dimension (mm) 126x69x67
Weight (g) 700
Storage Temperature -30 ~ +60˚C
Operating Temperature -10 ~ +45˚C
Also, I notice that when I research the 1/3" CCD camera above, that I get conflicting TVL's on a different website. It tells me 480TVL. Now I am really confused. What's the deal with a particular camera's specs. giving two different TVL specs? Am I being lied to?
Thanks.