Hitachi Microscope & Magnifier S-4800 Manual De Usuario

3 - 16

surface of the specimen.    At a shorter WD, higher resolution is attainable.     
At a longer WD, a larger tilt angle and a greater depth of focus is attainable. 

 
 
 
 
 
 
 

When a WD is selected from pull-down menu, the objective lens current is adjusted in order to 
focus an image at the specified WD. 
This function is useful for: 

1) 

To obtaining focus of the specimen surface quickly after introducing a specimen. 

2) 

Focusing the specimen at a specific WD. 

For X-ray analysis, the same WD (15 mm) should be used in order to maintain the   
X-ray take-off angle.    In that case, set WD from pull-down menu and adjust Z position of the 
specimen stage to focus the image.    (Use focusing operation only for fine adjustment.) 
The shortest usable WD is changed according to present accelerating voltage. The possible 
The WD range indication shows the present available value.       
The following table shows relation of WD and resolution, depth of focus or specimen tilting 
angle.   

 

 

Short               WD                Long

 

Resolution 

High                                                                      Low 

Depth of focus 

Shallow                                                                Deep 

Specimen tilt angle 

Small                                  Large 

 
 

WD

Specimen

Objective lens