Objective

Objective may refer to:

See also

Goal

A goal is a desired result that a person or a system envisions, plans and commits to achieve: a personal or organizational desired end-point in some sort of assumed development. Many people endeavor to reach goals within a finite time by setting deadlines.

It is roughly similar to purpose or aim, the anticipated result which guides reaction, or an end, which is an object, either a physical object or an abstract object, that has intrinsic value.

Goal setting

Goal setting may involve establishing specific, measurable, achievable, relevant, and time-bounded (SMART) objectives, but not all researchers agree that these SMART criteria are necessary.

Research on goal setting by Edwin A. Locke and his colleagues suggests that goal setting can serve as an effective tool for making progress when it ensures that group members have a clear awareness of what each person must do to achieve a shared objective. On a personal level, the process of setting goals allows individuals to specify and then work toward their own objectives (such as financial or career-based goals). Goal-setting comprises a major component of personal development and management.

Objective (optics)

In optical engineering, the objective is the optical element that gathers light from the object being observed and focuses the light rays to produce a real image. Objectives can be a single lens or mirror, or combinations of several optical elements. They are used in microscopes, telescopes, cameras, slide projectors, CD players and many other optical instruments. Objectives are also called object lenses, object glasses, or objective glasses.

Types

Microscope

The objective lens of a microscope is the one at the bottom near the sample. At its simplest, it is a very high-powered magnifying glass, with very short focal length. This is brought very close to the specimen being examined so that the light from the specimen comes to a focus inside the microscope tube. The objective itself is usually a cylinder containing one or more lenses that are typically made of glass; its function is to collect light from the sample.

Microscope objectives are characterized by two parameters: magnification and numerical aperture. The magnification typically ranges from 4× to 100×. It is combined with the magnification of the eyepiece to determine the overall magnification of the microscope; a 4× objective with a 10× eyepiece produces an image that is 40 times the size of the object. Numerical aperture for microscope lenses typically ranges from 0.10 to 1.25, corresponding to focal lengths of about 40 mm to 2 mm, respectively.