Simple observed emission line ratio images (linear scale, × 100) with respect to an H line for NGC 7009, ordered by decreasing ionization potential of the nominator image: [Mn V]6393.5Å/Hβ; He II 5411.5 Å/Hβ; [O III]4958.9 Å/Hβ; He I 5875.6 Å/Hα; [O II]7330.2 Å/Hα; [N II]6583.5 Å/Hα; [S II]6730.8 Å/Hα and [O I]6300.3 Å/Hα. The 3× 3-σ clipped means on the signal-to-error above 3× the error on the ratio are: 8, 35, 47, 60, 26, 41, 34 and 29, respectively.