Contrasting open star clusters NGC 2477 (dense and in centre) and NGC 2451 (loose and below centre) in Puppis. This is a stack of five 2-minute exposures with the 135mm L-series Canon telephoto lens at f/2.8 and Canon 7D at ISO 1250. This was taken from Atacama Lodge in Chile, May 2011. The field of view simulates a binocular field (roughly 7°).
The contrasting open star clusters in Puppis: NGC 2477, the rich condensed cluster at left, and NGC 2451, the loose and sparse but bright open cluster at right. It has a prominent yellow star amid the blue stars. This is with the Borg 77mm astrographic apo refractor (330mm focal length) at f/4.3 for a stack of 5 x 8 minut exposures with the filter-modified Canon 5D Mark II at ISO 800.