如果 镜头的分辨率比cmos的分辨率小的话，会出现什么现象？

chengsean

<DIV class=quote><B>以下是引用<I>3homer</I>在2007-3-1 12:32:05的发言：</B>
什么叫镜头的分辨率,你是意思是不是镜头的光学尺寸小于Sensor的,如果这样,那么图像就会有暗角啊, 什么叫镜头的分辨率,你是意思是不是镜头的光学尺寸小于Sensor的,如果这样,那么图像就会有暗角啊

<P align=right><FONT color=red>+1 RD币</FONT></P></DIV>


The 分辨率, I think it means resolution. If it means resolution, the fall-off in corner will
not appear. The 暗角 you means is the image circle of lens. If the image circle of lens
is smaller than sensor then the 暗角 will appear.
What happen when the lens resolution is smaller than sensor ?
The aliasing can be redueced. You can image that. Lens is to generate the signals to
sensor and sensor is to sample the signal from lens. From the Nyquist Sampling
Theorem, if you want to reprodued the signals the sampling frequence should be large than
2*signal frequcne. But the frequence of the signals always large than sensors, the aliasing
appear. If you can reduce the frequency of the signals, the aliasing will be reduced. Some
digital still camera will put a low pass filter in the camera module to reduce the aliasing. The
low pass filter is to reduce the signals frequence.  [br]<p align=right><font color=red>+3 RD币</font></p>