ABSTRACT
In this chapter, the author chose a large subject with a variety of elements, suitable for a short refractor; the Heart Nebula was discovered by William Herschel in 1787 and is predominantly an emission nebula, with some dust clouds and small star clusters. The camera was attached to the back of the refractor’s field flattener via its 48-mm thread, at the right spacing, to ensure round stars into the corners. This required a careful analysis of QHY’s mechanical drawings for its camera, adaptors and spacers to match the flattener spacing and thread. The exposure plan used two filters with very different glass thicknesses and which required re-focusing when they were changed over. The author sets up the guider and imaging scope to approximate focus, with the help of a bright star and a cycle of short exposures.
