Advanced Imaging Techniques

Narrowband Imaging

What is narrowband imaging? In normal color imaging, three filters (red, green, and blue) are used to separate the primary colors of the visual spectrum.  Red, green, and blue (RGB) filters are designed to approximate the color sensitivity of the human eye, so that the resulting image is true color.  Each of the RGB filters… More »

Taking Mosaic Images

Mosaics are large, usually wide-field, images stitched together from several smaller images.  The reasons for creating mosaics include obtaining a wider field of view with a small CCD and/or long-focal-length scope, and making larger image files for creating larger, more detailed images and prints. There are two major steps involved in creating mosaic images.  The… More »

Imaging Supernovae

Imaging Supernovae Professional astronomers distinguish between two main classes of supernovae.  The distinctions have to do with the type of explosion occurring, how it is triggered, the resulting light curve and the atomic elements visible in the spectrum of the supernova.  However, for amateur astronomers’ purposes we can consider two very basic types of supernova: … More »

Imaging Asteroids

Imaging Asteroids While asteroids do not share the stunning beauty of their solar system cousins the comets, they are worthy CCD targets nonetheless.  Only the most powerful professional telescopes have the capability to resolve features on the surface of asteroids — and then only the closest or largest asteroids.  The best we amateur astronomers can… More »

Imaging Comets

Imaging Comets There are basically two types of comets:  faint ones and bright ones.  The bright ones certainly get all the glory, and names like Halley, West, Hyakutake, and Hale-Bopp are all familiar to most amateur astronomers.  Occasionally a fainter comet will take the spotlight such as when Comet Shoemaker-Levy 9 impacted Jupiter in 1994. … More »

Getting the Most Detail

There are two ways to think of getting the “most” out of an image:  capturing the faintest possible details, and capturing the finest possible detail.  The ideal situation would involve getting an image with both extremely fine detail (high resolution) as well pulling in the dimmest wisps of nebulosity or the most elusive galactic spiral… More »

Planetary Imaging

Much has changed in the last few years regarding the way in which planetary images are taken.  Planetary imaging used to be one of the most challenging aspects of astronomical imaging, but new technology has now made capturing high-resolution pictures easy and inexpensive.  CCD cameras and inexpensive digital cameras can be used for planetary imaging,… More »

Color Imaging

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 yield much more detail and information than an image through a color filter.  LRGB imaging… More »

Imaging Sequences

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 best way to start capturing a high-quality CCD image is to begin with a single… More »

Calibration Images

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 situations, but they are discussed below.  And there are ways to improve upon the basic… More »