How To Isolate Subjects, Part 2

© Mike Spinak

[Editorial Note: This is the second part of a series which started here, showing methods of isolating photography subjects.]

In the picture of the garlic mushrooms growing on a tanoak leaf, above, I isolated the subject from the background by photographing the subject lit up against a comparatively dark background. In this case, I did it by using a flash. I placed the flash about a foot behind the subject, and a little bit above the subject, pointed at a slightly downward angle onto the mushrooms. The ambient lighting was actually much more even than you see in this shot, with the background lit a similar amount to the foreground subject. When I greatly increased the light on the mushrooms by flashing them, I had to compensate for this by decreasing the exposure settings for the shot, to prevent the mushrooms from being overexposed. I did this by decreasing the amount of time the shutter was open to 1/250th of a second. This was 1/400th the amount of light that would have been necessary to photograph the mushrooms without flash. By using the flash this way, I made it so that the photo shows the mushrooms still well lit, while the photo only exposed the background with 1/400th of the light necessary for the background to be well lit – thereby making the background appear black.

To show you the difference this technique made, here’s almost the same picture, made a couple minutes earlier, photographed strictly with the natural light on the scene, exposed for 1.6 seconds, instead of 1/250th of a second.

© Mike SpinakOther than changing my angle a bit, shooting the mushrooms and leaf from a slightly lower angle for the flashed picture, the only difference between the two is the flash-with-less-exposure versus no-flash-with-more-exposure. As you can see, it made a marked difference in the appearance of the picture. (In my estimation, the natural light version is a decent picture, too; it just wasn’t what I had in mind.)

Photographing the subject lit up against a comparatively darker background is a simple way to isolate the subject from the background.

When using flash, the technique, of course, necessitates having a flash. For tiny subjects like these mushrooms, which are a fraction of an inch tall, you can place the flash close to the subjects, and overpower the natural light with a single flash. For larger subjects, like a person, it sometimes requires more than one flash to overpower the natural light. (In the dark woods, on a darkly overcast Winter day, one flash will do; In full sunlight, it’ll require more than one small flash.)

Additionally, if you want to get the flash off the camera, such as the way I flashed these mushrooms from behind, then you’ll need a way to fire the flash remotely – probably either by infrared remote, radio controlled remote, or with a flash cable. Off camera flash often looks better than on camera flash. On camera flash makes the angle of light incidence on the subject almost the same as the angle at which you’re taking the picture of the subject. This causes a couple of characteristics which are often undesired: 1) it doesn’t show much shadow at all on subjects, which makes the subjects look “flat”; 2) it often tends to reflect a lot of specular highlights, off of anything shiny, back into the lens.

While the natural light just wasn’t “cooperating” with me for the picture I wanted to make, with the garlic mushrooms, this technique can often be done with natural light, too. In fact, of the numerous pictures I’ve shown on this website which isolate the subject by showing a bright subject against a darker background, all of them except the garlic mushrooms were lit that way with natural, ambient light. For example, this shot of a passiflora tendril and leaf tip was made strictly with natural light.

© Mike SpinakAs in the case with the garlic mushrooms, the light on the passiflora tendril and leaf tip is coming from behind. When using this kind of isolating technique, I often prefer for small, organic subjects to be lit from behind. I like the way that this brings out structural details of the organism, such as the way the veins in the leaf look, above.

For natural backlit subjects against dark backgrounds, first look for light coming from behind the subject you want to shoot, and place yourself at an angle where the subject is lit from the rear. Or, as the case may be, if you have a special subject, be patient while the Earth rotates, until the sun is behind the subject. (With the passiflora tendril, above, it was growing curlier and twisting on its axis; I waited for more than a day for it to grow to look as I sought, and for it to twist into the angle I sought, and for the light to be right, in relation to the way it twisted.) Next, look for an angle that still shows the subject lit from the rear, but allows you to frame the subject with the background entirely in dark shadow.

Circumstances which allow this happen more often than you might think. If you know about the possibility, and look for it, you can usually find it – or find it within a few minutes, as the angle of the sun shifts. This is especially true in the dark woods, where most of the woods are in shade, but with many small patches of direct sun shining through. It’s easier to frame these kinds of shots with the background entirely in shadow, if you shoot the picture with a long lens. Long lenses have narrower angles of view, and that helps take advantage of smaller patches of shade, behind the subject, instead of needing large ones.

Subjects can’t be lit from behind, if they’re not transparent or translucent. If the subjects are opaque, as is usually the case with subjects that aren’t very small, then making the subject bright against a dark background has to be done with light coming more from the front side than the rear. Subjects can be isolated with bright light against a dark background with light either from the front or the back.

Lighting fairly small subjects against a dark background, with natural light coming more from the front side, could hardly be easier. You just need sunlight falling on the subject; then you cast a shadow behind the subject, and frame the picture so that the shadow is your background. You can often do that just by standing in a way that casts your shadow right behind the subject, like I did with this stock shot of a Macloskey’s violet.

© Mike Spinak

With many larger subjects, you can’t just cast a shadow behind the subject. Nonetheless, there are still many cases, such as this American kestrel, where the natural light allows for isolating the subject against a dark background.

© Mike SpinakWith this kestrel shot, it’s just a matter of the angle, with light falling on the subjects from the front right, while the edge of the grove of Monterey pines in the background was in dark shadow.

If you’re attentive to the light, or if you have the means and the skills to modify the light, then isolating subjects this way is a great technique to have in your skill set.

Go give it a try.

Garlic Mushrooms (Marasmius copelandii), Big Basin State Park, Boulder Creek, California

Passiflora Tendril and Leaf Tip

Macloskey’s Violet (Viola macloskeyi), Butterfly Valley, California

American Kestrel (Falco sparverius), Bluff Top Park, Half Moon Bay, California

All pictures and text are © Mike Spinak, unless otherwise noted. All pictures shown are available for purchase as fine art prints, and are available for licensed stock use. Telephone: (831) 325-6917.