Choice of Equipment / Requirements

What you will need



You will need the following things to perform good variable star photometry with digital cameras:

- The camera itself: while this tutorial is focused on DSLRs, any digital camera will do as long as it meets the following criteria (all popular DSLR cameras, even the cheaper entry-level models, will meet these requirements):

-- you can extract images in so called RAW format, and the format is supported by one of the software packages discussed in this tutorial (..........). Working with JPEG images will not give good results.

-- you can focus manually. Auto-focus will not work very well on the night sky most of the time

-- you can manually select a shutter time [exposure time ??] of several seconds.   

-- A lens for your camera that allows to get the variable star and comparison stars in the central region of a single image. For DSLRs and bright variable stars, a focal length of ca 50 -90 mm will work just fine. You do NOT need a telescope unless you want to do photometry for really faint stars, we'll focus on bright stars here.

- A simple tripod. For bright variable stars, you do not need a motorized telescope mount or even a telescope mount at all. Even those little pocket-size tripods will do as long as they can support the weight of your camera.

- The software needed to evaluate the star field images. This tutorial discusses the most poular software (some are freeware, some are commercial or are add-ons to a book)[...link to chapters....].

- A PC that can run one of the these software packages (check the requirements of those packages). Last but not least, you will also want to use a PC to report your measurements over the Internet to the AAVSO and share your results with the scientific community.

- an observation point that offers an unobstructed view to the variable and the comparison star during the observation period. Of course a country-sky is better for photometry than a "light-polluted" city-sky, but even in the city you can often do meaningful bright-star-photometry with a DSLR.