[victorchan32]

Would you tell me what is meaning? I found that some camera which is 1/1.8. Actually, this value is smaller or larger better ? Thank you very much.

[Vistaresort]

1/1.8" larger

[victorchan32]

you mean that it is better in smaller value.

[Vistaresort]

1/2.5" smaller, about 5.5mm x 4mm

[victorchan32]

What is this 感光元件大小????
Would you explain to me or reference web site to me.
Thank you so much

[Bus Fans]

Have a look of this:

http://www.dpreview.com/learn/?/Glossary/Camera_System/sensor_sizes_01.htm

Then, you'll know that the size is determined by old-fashioned TV camera vacuum tubes and there is no specific mathematical relationship between the diameter of the imaging circle and the sensor size.