of the adjusting ring further arrangements of the axial guide and guide cam are conceivable instead of the actuation of the adjusting ring 27 for axial displacement of the objective lens group 13 a motorized adjusting drive not shown could also be provided a corresponding axial movement of the objective lens group 13 could be executed by the motorized adjusting drive by actuation of an actuating button not shown the use of linear motors is advantageous for such an application since the movement of a linear motor can be used without a gear being necessary to convert a rotational movement into a linear movement such linear motors which are distinguished by a low energy consumption are already available as standard components the objective tube 41 is coaxially surrounded by a glare protector 45 on the side facing toward the object the glare protector 45 is mounted for axial displacement on the tube 41 so that the set position of the glare protector 45 is not inadvertently changed friction elements 47 such as felt for example are provided a maximum pulled out position of the glare protector 45 is ensured by a projection 49 formed on the objective tube 41 and a projection 51 formed on the glare protector 45 which strike against each other at the maximum pulled out position of the glare protector 45 a ring element 44 is provided for fixing a protective disk 43 and is fixedly connected to the objective tube 41 in.