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AAVSO Photometry CHOICE Courses

At present there are three AAVSO CHOICE Photometry courses, two for traditional CCD cameras and one for DSLR cameras. These are intense courses taught over a limited time and require daily commitment of time from each student to complete successfully. This includes time taking images as well as participation in discussion questions on the forum. Students will be asked to share their results with the instructor and with other students. An “open book” final test is required from each student. Please consult the syllabus to ensure you have the time commitment to take these courses.

CCD Photometry Equipment Requirements

The purpose of the CCD Photometry – Part I (CCD 1) and CCD Photometry – Part II (CCD 2) CHOICE courses is to instruct students in basic photometry so that they can carry out research on light variation of stars and star systems and submit their observations to AAVSO, other organizations, or use the results for their own research activities.

DSLR’s, CMOS, and color CCD cameras are not suitable for CCD1 and CCD2.  AAVSO is currently investigating mono CMOS cameras and may integrate them into a AAVSO CHOICE course in the future. However, at this point in curriculum development mono CMOS cameras are not supported in CCD1 and CCD2.  The instructor will provide images for students with cameras which are not supported by the course.

Photometric filters are different from those designed for astrophotography. Students contemplating photometric observations should purchase at least two photometric filters (Johnson V and Johnson B are recommended). Students coming from astrophotography who are not sure that they wish to pursue photometry but want to enroll to see if photometry interests them may use their RGB filters for both CCD 1 and CCD 2 but should realize that only G (green) can be reliably transformed to the Johnson V system for submitting data to AAVSO.

Students in CCD 1 and CCD 2 are assumed to have suitable software and know how to use it for such activities as taking, manipulating and analyzing images. For image analysis we encourage and actively support the use of AAVSO’s VPhot tool. Please consult the AAVSO Guide to CCD Photometry before enrolling for recommended software.

DSLR Photometry Equipment Requirements

Students undertaking the DSLR Photometry CHOICE course are expected to be using a reasonably modern 14-bit DSLR camera and be familiar with its operation, including how to change settings for ISO, shutter, aperture and file format. Images must be able to be saved in the camera’s native RAW format. 12-bit analog to digital converters are not considered suitable for photometry.

Other digital camera types, including astronomical one shot color CCD or CMOS cameras may be suitable. However the course presenter has no experience with these “One-shot” color cameras and will not be able to help with camera operation problems.

In previous courses many students were unfamiliar with the photometry software they chose to use, in particular the free IRIS software. This resulted in a great deal of the presenters’ time being spent solving software issues instead of teaching DSLR photometry techniques. Therefore IRIS will NOT be supported in future DSLR Photometry courses.

Recommended photometry programs are AIP4Win and MaxIm DL versions that support DSLR cameras. Other photometry programs are available but the presenter may not be familiar with their operation.

AAVSO 49 Bay State Rd. Cambridge, MA 02138 aavso@aavso.org 617-354-0484