Collimation is the procedure of aligning each elements in a telescope to make light to it’s best focus point. Telescopes are generally collimated to be more accurate and focused.
The word “collimate” comes from the Latin word collimare, means”to direct in a straight line”.
Captain Henry Kater (An English physicist and astronomer) invented Collimator in the year 1825. Collimators are widely used in astronomical observations
Collimation and Decollimation
This is the process of aligning each component in an optical instrument to have perfectly focused light. A collimator is an equipment that narrow-down a beam of waves/particles, by a collimation technique. Narrow can mean to be aligned in a particular direction (i.e., create collimated light or parallel beams ), or to create the spatial cross-section of this ray or beam to become narrower (beam limiting device).
An optical collimator is consisting of a curved mirror or lens having some light source and an image created at it’s focus point with little or no parallax.
The Optical collimators are utilized in the collimator sight, which is another reticle during its focus or a simple optical collimator using a crosshair as gun sights. The viewer in this process just sees an image of the reticle. If we include a beam splitter in these arrangements enables the viewer to see the reticle with the field of view additionally.
Do we need to collimate a Schmidt Cassegrain telescope?
Under normal usage, it’s not required, so without collimating a Schmidt Cassegrain telescope will work perfectly. There is no extra tool requirement also in contrary to collimating a Newtonian, where we have to use an SCT. You will have to check that the collimation, therefore.
Why we need Collimation?
Collimation identifies each of the optical components in a tool being in their intended optical axis or not. Additionally, it indicates the practice of fixing an optical device so that its components are on that axis (parallel and directional, etc.). The expression denotes how each element’s axis ought to be parallel and centered, so light originates in the eyepiece, with respect to your telescope. In the Amateur reflector telescopes, need to be re-collimated periodically to keep performance at in optimum level. This may be achieved by visual techniques like looking down the assembly with no eyepiece to be certain that utilizing a Cheshire eyepiece line up, or with the guidance of a laser collimator or autocollimator.
All telescopes have been collimated at some point to bring light to its best focus. So, collimation process of aligning all apparatuses in a telescope is essential part for space research and observation.
Application of Collimator:
Collimators used for various application starting from space research to radiography and camera device. An interferometer is used for proper collimation for the laser source with sufficient coherence length.
X ray Collimator:
Collimator (beam limiting device) is used in linear accelerators for radiotherapy. They can restrict the field size of a beam and help shape the beam of radiation from the linear accelerators system.
In X-ray radiography, gamma-ray, and neutron-based imaging, a collimator is mandatory, a system that filters a flow of streams that parallel to some direction is permitted through. It’s tough to focus these kinds of radiation source into a picture with only lenses. This is the reason the collimator is regularly used with electromagnetic radiation in near-optical or optical wavelengths. In addition, collimators are utilized in radiation sensors, detectors in power stations for better sensitivity.
How does the Collimation improve image quality?
Appropriate collimation is among those facets of maximizing the imaging procedure. It prevents exposure of the body by generating scatter radiation, and in addition, it enhances image quality.
What is collimation in radiography?
In radiography, The beam has to be in the region of interest on the patient so collimation is employed to protect the patient from the undesired radiation, which are evident from different radioisotopes or waves.
Why is collimation important in radiology?
X-ray collimation for fluoroscopy and radiography imaging is very important for patient dose and image quality. Collimating into the volume of interest reduces the dose, hence the radiation issue.
Limitations of Collimator :
Collimator improves resolution and reduce beam intensity. “The gamma-spectrometry used in Mars Odyssey” is a tool that is gamma-related one for this reason. Efforts have been made to substitute collimators with electronic analysis and utilizing other instruments.
Collimator for Aeroplane:
Which material is used as a collimator?
Material used for collimators are lead, tungsten, molybdenum, tin, bismuth, high-density plastics, and many more.