I'lfOTOMlCROCR.iriiy .1X1) TECHNICAL MICROSCOPY 10.1 



.III iiuiTltd rial iiiia^f of tlir nlijiTl Oi at Oj luit tin.- rays art' iiilt-r- 

 i-fptcd by the lower lens of the eyepiece hefori' the real image is 

 fortiied. The lower e>epiece lens in coinl)iiiatio!i with the upper 



Kig. 2 — Researih \\\x- i.l micro 

 sco()c by Zeiss. Large barrel for 

 photo- micrography; revolving 

 mechanical stage, and sliding ol)- 

 jective changers. 



Kig. .V -Kesoarch type of micro- 

 scope by Spencer Lens Co. Large 

 barrel for photo-micrography: a 

 large revolving stage with grad- 

 uated circle, and a removable 

 mechanical stage. 



eyepiece lens forms a magnified \ irlual image (^4 of the real image Oz. 

 There are two magnifications of the object and the resulting final 

 magnification is the product of the magnifying powers of the objective 

 and the eyepiece. 



It should be noted that the objective produces an enlarged image 

 of the object and that the c\epiece further magnifies this image; 

 from this it is evident that if detail is lacking or if the image is not a 

 good likeness of the object, the eyepiece will not make up for the 

 shortcomings of the objective. The objective, then, becomes perhaps 

 the most important part of the whole outfit. N'o one objective will 

 serve for all purposes because of the limited range throughout which 

 each particular objecti\e is most useful; hence it is necessary to have 

 a whole batter>- available so that the iil>irr-ti\e may be selected to 

 suit the requirements of the work. 



