Tutorials

The most basic processing step after image calibration is simply altering the way in which the image is displayed so it looks best on your computer screen. Computer screens are limited to displaying 256 shades of grey. This is all...

A filter is an image processing routine applied to an image to enhance details. This is usually done in one of two ways: by smoothing the image to remove noise and show subtle features hidden by the noise, or by...

Most astronomical CCD cameras create color images by combining black and white images taken through red, green, and blue filters. In theBasics of Taking CCD Images section we gave the example of the Trifid Nebula, M20, imaged using this technique....

The most basic use for filters is for taking color images. By shooting through red, green, and blue colored filters it is possible to capture objects in full color. Filters can also be used to enhance certain details, to block...

When starting in CCD imaging, price often determines what camera you buy. Relatively inexpensive CCDs typically have smaller chips, lowerquantum efficiency, and lack certain features such as self-guiding and compatibility with certain accessories. Advanced CCDs take up where the smaller...

Schmidt-Cassegrain telescopes and refractors are the most popular systems for CCD imaging. Most SCTs come as a complete system with optical tube and fork-mount as one assembly. Less expensive refractors may include a small German equatorial mount, but many high-end...

The most popular telescope design used for CCD imaging is the Schmidt-Cassegrain. This design offers a lot of versatility for both imaging and viewing. This fact as well as their portability and moderate price make them very popular instruments. However,...

If you have not already, please read the section on Basic CCD Accessories for some of the most common items used to make imaging easier. Below are some of the best accessories for advanced imaging. Autoguiders If your CCD camera...

In the Basics of CCD Imaging section, a simple dark frame was used to calibrate the images. Subtracting dark frames is the most important calibration process, but flat fields can also be critical. Bias frames are only used in certain...

By taking multiple images it is possible to significantly reduce the noise in a CCD image allowing for more enhancement later. See the Advanced Image Processing section for details on combining and processing sequences of images. A Single Image The...

LRGB In the Basics of CCD Imaging section, only RGB imaging was discussed. The shortcoming of RGB imaging is that the individual filters cut down on the amount of light reaching the CCD. An image through the clear filter will...