In Security camera field, auto focus zoom camera is key component in the speed dome.
The camera module main supplier is including SONY, Panasonic, LG, CNB and etc.
How to measure the Auto focus speed (AF speed)?
1. zoom speed:
When you control the zoom times from 1x to 18x, the speed must be quick.
2. Auto focus speed
When you choose the 18x zoom position, the image must quickly become sharp image.
If we compare with DV, the security zoom camera does not care about the noise that stepping motor make.
What the speed is good?
I do not have the quantification number.
We always compare with SONY 18x AF camera module
(FCB-EX480). See the demo film as below.
Auto focus Algorithm is still secret. But it usually divided two step.
step 1: tracing curve
This noun is invented by
Step 2: using contrast Algorithm or math differentiation to get local maximum value
Taiwan AF manufacturer follow step1 and step2 to do develop the zoom camera but most of China AF manufacturer only do step 2.
I got the
General speaking, the AF speed from china maker could not compare with brand maker (SONY and etc).
See the demo film as below.