Digital single lens reflex cameras are now commonplace with a number of manufacturers offering a variety of models and many options for lenses. They range from relatively inexpensive consumer level bodies, often packaged with average quality zoom lens, up to very expensive professional bodies and l...

Setting Up & Using the Camera In this document I’ll describe my current image acquisition process. Some of it will be generic in nature. However, much will necessarily be specific to the DSLR and other hardware/software that I use.

There are a number of commercial and freeware packages suitable for opening DSLR RAW files and performing aperture photometry, including MaxIM DL, AIP4WIN and IRIS. I use AIP4WIN because it came bundled with my copy of The Handbook of Astronomical Image Processing, Berry and Burnell (2009). I have h...

You may think that when you measure a star through filters that the derived magnitude is a real measure of its brightness but, unfortunately, that is not the case. The UBVRI filter system was created by Harold Johnson in the early 1950s and was a major step forward in measuring the brightness of sta...

In the early days of photoelectric photometry, the detectors were single channel and required a focal plane diaphragm to isolate the target stars. Thus, all measures were sequential and usually involved a sequence like sky background, comparison star, variable star, variable star, che...

Having determined how your images need to be corrected to conform to the standard system let’s look at the way the atmosphere effects these measures. This atmosphere is rather unpredictable, even when it appears clear, and the best approach is to make your observations in a manner whi...