# magnification of objective lens of microscope

The magnification of objective lens of microscope is tube length divided by focal length of the objective lense. But Serway and Halliday give different definitions of tube length. One says the tube length is the distance between the objective lens and the eyepiece lens, another says it is the distance between the focal points of the objective and ocular lenses. Which one is right?

• The distance between the focal lengths is what you are looking for, if you asssume that the magnificiation is tube length divided by focal length. However both the definitions are correct and it is matter of semantics. – cobra121 Mar 20 '18 at 22:34
• But in serway's college physics 9th edition figure 25.7, tube length is the distance between the two lenses while in Halliday's fundamental of physics 9th edition figure 34-20 the tube length is the distance between the two focal points – David HM Mar 20 '18 at 22:45