Avoiding black backgrounds in macro photography.

There are many ways to do macro photography. Different equipment, techniques, and post-processing magic all contribute to the end result. My favourite way of shooting small insects and the like is to use a crop sensor DSLR with an extension tube, macro lens, and ring mounted macro flashes. I prefer this method because I can usually do it without a tripod, require only one shot, and can do it in the field without disturbing the organism. The only problem tends to be the pitch-black background that results when there is a void behind the subject.

This happens even on the brightest of days. It has to do with camera settings. As a matter of course I prefer to use low ISO values (100 or 200 usually), fast shutter speeds (maximum flash synch speed at 1/250th of a second), and very small apertures (often between f/45 to f/57). The low ISO means electronic noise will be kept to a minimum. The fast shutter speed reduces blur from the motion of me or my subject's. High f/values produces enough depth of field that I can get most of the organism in focus. It all makes perfect sense.

The problem comes when there is empty space behind the subject. Flash is providing the only measurable light; any that is not returned in a significant amount produces black zones which can seriously impair the image. In order to prevent these dark zones, there are a few options. Increase ISO to such a value that the background can be properly exposed but at the expense of significant noise. Do focus bracketing with a lower aperture and use a program after the fact to seamlessly stack the images together blending only the in-focus parts. The caveat here is that you need a tripod, take many images, use a focus stacking drive or appropriately fine screwed bellows mount, and stack them together later using the proper software. Then there is what I did to get the image on the right.

Use the back of a paper plate and place it just behind the focal point. The light that goes past the subject hits the white surface and returns to the camera where it is picked up as white or a very light grey. You also get the benefit of having a neutral surface to colour balance off of. Now, instead of black, there is a bright background which neither causes bloom (from overexposure) nor does it swallow up parts of the creature.

I make sure that the plate is perpendicular to the camera both horizontally and vertically. It doesn't have to be centered, but make sure there are no markings or engravings that will be rendered in the image. The only difficulty with the process is that it means holding a plate with one hand while operating a modestly heavy camera with the other. I rarely get what I want on the first shot and so I take several images, hand-held, while maneuvering both hands to obtain the photo. If I am doing this in a controlled environment I may tape the plate in the position I want and use two tripods; one to hold the camera and the other to hold the subject. There are many variations on the setup, I have probably used them all.

Keep in mind that macro photography is rarely a one-and-done endeavor. I may take ten photos of one setup. Two or three may be good; of those one will be the best. Although I find all kinds of interesting things to photograph not all of them are taken into post. I think I can safely say that for every 20-30 actuations of the camera I get anywhere from one to five useful images. Some days I am more successful than others. Equipment is part of the solution but so is time, patience, technique, and luck. As a photographer, I will take all the luck I can get.

Thanks for reading.     Ericspix     Eric Svendsen