What is the trick for checking the coolant level on this car?

The min/max lines are about a foot down a narrow dark crevasse, If the light into the engine compartment is just right I can barely make out where they are, but cannot tell where the coolant level is at all. The tank itself is a bizarre twisty shape so I can't just look in there with a flashlight to estimate the height.

When it was last in the shop they said the coolant level was OK, but when I take the radiator cap off when it is cold the fluid level is well below the drain tube, just about at the bottom of the "neck", which does not look right to me.