Effect of extinction: filled circles depict the standard LDCs (h′₁, h′₂) without interstellar extinction; filled stars depict them when assuming an extinction of A_V = 1 mag. All data are normalized to solar conditions. The solid black line with labels is a fit to the reddening-free data points; the dashed violet line to the reddened ones. The coloring of the symbols according to field strength follows our standard color scheme.