Mailbag: How to light a photo backdrop with the MP-E lens

A reader asks:

I also have a MP-E lens with the MT-24EX flash unit. I was curious to know something I didn’t see you mention in your recent blog post about this setup.

Could you share any technical points regarding how you achieve the visible backgrounds with that lens? In general, I get very nice shots with everything beyond the focused subject completely blacked out.

Since dark areas in photographs are the bits that aren’t sending light to the camera, it follows that getting a visible backdrop means applying light behind the subject.

Earlier, I wrote that the black backdrop in insect macrophotography with flash is often a sort of default setting. When bright flash is applied to a subject in the foreground, the background will fade to black as a matter of course. Consider this shot of Acacia ants taken in a Panamanian forest:

Pseudomyrmex spinicola on their nest thorn, Panama

Although I snapped this picture during the day, the photo is mostly black. That’s because little ambient light from the forest penetrated the small aperture I used to gain depth-of-field. Nearly all the light comes from the flash.

To bring up the background means either adding a second flash aimed behind the ants, or it means positioning something close enough behind the subject so that it is also lit by the foreground flash. In this case, I rigged a solution in the field:

A fallen leaf already suspended in the ants' tree is easily re-hung a few inches below it's original position to bring it behind the thorn of interest (photo by Jo-anne).

Shooting away- no more black background! The white tracing paper serves to soften the harsh light of the flash, while the orange leaf provides ambiance.

With a colorful leaf arranged a few inches behind the ants’ thorn and reflecting the flash, the resulting photographs have a different tone:

Pseudomyrmex spinicola on their nest thorn.

I was lucky here that the thorny undergrowth provided an easy way to suspend a leaf. Paper clips are more reliable, and it’s probably a good idea to carry a few into the field. In any case, the principle is the same: put something close enough behind the subject to reflect the flash.