Here we are looking at the southerly constellation of Puppis, focusing on the portion below Canis Major, in particular the right triangle comprising π, σ, and ζ Puppis.  Being able to recognize this triangle is the gateway to spotting one of the most extreme contrasts between open cluster types in the sky, even more radical than M46/M47.  We are talking about NGC 2451 and NGC 2477, close together along the line from π to ζ.  NGC 2451 is extremely loose and sparse, but with a beautiful color contrast between the bright orange star in the middle and the remaining cluster members; NGC 2477 comprises hundreds of uniformly faint stars, creating a nebulous appearance.  The difference in appearance is explained by their true size and distance ~ NGC 2477 is about 3,600 light years away and contains at least 300 stars, while NGC 2451 contains dozens of stars in two separate clusters, the nearer being 600 light years distant and the farther one being 1,200 light years away.  Unannotated image.