The results of illumination calculated in two methods are different !

<P>I use the sample lens "cooke1.len" to analysis.</P>
<P>[method-1]</P>
<P>calculated from [analysis]=[illumination]
<img src="data/attachment/forum/dvbbs/2005-3/200532214394311.gif" border="0" onload="if(this.width>screen.width*0.7) {this.resized=true; this.width=screen.width*0.7; this.alt=\'Click here to open new window\nCTRL+Mouse wheel to zoom in/out\';}" onmouseover="if(this.width>screen.width*0.7) {this.resized=true; this.width=screen.width*0.7; this.style.cursor=\'hand\'; this.alt=\'Click here to open new window\nCTRL+Mouse wheel to zoom in/out\';}" onclick="if(!this.resized) {return true;} else {window.open(\'data/attachment/forum/dvbbs/2005-3/200532214394311.gif\');}" onmousewheel="return imgzoom(this);" alt="" />
illumination =0.11089/0.39542=0.280436
</P>
<P>[method-2]</P>
<P>calculated from [MTF]
Cooke Triplet f/4.5
                                                           WAVELENGTH   WEIGHT  NO. OF RAYS
      FIELD (X,Y)=( 0.00, 1.00)MAX, (  0.00, 20.00)DEG      656.3 NM       1      1622
      RELATIVE ILLUMINATION =  57.2 PER CENT                546.1 NM       2      1620
      ILLUMINATION (UNIT BRIGHTNESS) = 0.022212             486.1 NM       1      1614
      DISTORTION =   1.12 PER CENT</P>

请问,你的接收器的大小是多少?

请将具体的设置参数列一下.