How are the smooth, colorful backgrounds created in these wildlife macro photos?

Question

I've been following a biologist and photographer for a while, and it always strikes me, how visually pleasing his images are because the background always complements the subject very well.

Question 1: How are the backgrounds-colors in all of these images, so perfectly complementary to the subject-colors? Is digital manipulation involved?

Question 2: Is the unusual texture of the background natural?

Question 3: Is it possible that gels are involve in the creation of such complementary colors?

Context for Question 2: Most macro lenses peak at f2.8, I've never obtained such a beautiful and smooth background even at this aperture.

Images in question

The following images Copyright Paul Bertner.

Answer 1

Question 1: How are the backgrounds-colors in all of these images, so perfectly complementary to the subject-colors? Is digital manipulation involved?

The photographer surely made some adjustments that affect the colors, such as adjusting white balance, saturation, highlights, etc.

I wouldn't describe the background colors in the examples you cited as complementary -- the complement of green is red or magenta (depending on the color model), and the complement of blue is orange or yellow. The colors are certainly different and provide some contrast, but not all of Bertner's photos are like that. Some have similar colors (e.g. a green frog on a green background). I think that Bertner, like any photographer, looks for opportunities to compose an attractive image, and that often involves looking for contrasting background colors.

Question 2: Is the unusual texture of the background natural?

There's nothing unusual about the texture -- it's just heavily blurred. It's actually difficult to avoid that sort of strongly blurred background when you're shooting macro, where the camera is very close to the subject.

Context for Question 2: Most macro lenses peak at f2.8, I've never obtained such a beautiful and smooth background even at this aperture.

You don't even need to go as wide open as f/2.8 to get that kind of blur. Here's an example I created in 60 seconds:

The subject here is a Lego minifigure standing on the back of my sofa. If you've ever seen a mini figure, you'll know that the photo covers a vertical distance of maybe 1.5". This was shot using a 100mm f/2.8 macro lens at f/5.6, and the distance from camera to subject was around 6-8" The red background is a textured red blanket that happened to be laying on the sofa. Here's another shot of the same scene:

I shot this one from further back, maybe 18", and at f/32, so that you get more depth of field. As you can see, you don't need to shoot at an enormous aperture to get a lot of background blur if the subject is close to the camera.

Question 3: Is it possible that gels are involve in the creation of such complementary colors?

It's certainly possible, maybe not even unlikely, but I don't think it's necessary to assume that -- the colors don't look unnatural to me.

Answer 2

He describes his Macro process on his blog. https://pbertner.wordpress.com/how-i-shoot-macro/

While you selected a few that have that effect, many don't. I don't think its anything more than composing the piece, being patient, and waiting for the specimen to be in the right contrast area with the right lighting. He does mention occasionally using flashes for fill. The other thing specific to your question he says is,

"For example, by using a larger aperture and rolling a leaf, the edge can fade away, leaving a smooth green foreground."

It sounds like he also shoots predominately free-hand but with lots and lots of different manual focuses deliberately trying to not get edge to edge sharpness but a sharp focus area and then very soft everywhere else. I half-expected him to say he tilt shifts or uses something like a lensbaby at times.

Answer 3

The photographer has arranged a shallow depth of focus, and has chosen a plain background. And, according to his blog, has selected from a very large number of less successful attempts!

Answer 4

Context for Question 2: Most macro lenses peak at f2.8, I've never obtained such a beautiful and smooth background even at this aperture.

You don't need a huge aperture. You can get better bang for your buck getting smooth backgrounds using a longer lens rather than a wider aperture. The amount of background blur depends on the size of the entrance pupil, not the f-number, and the pupil increases in size with focal length.

For example, the following picture was shot using a cheapo Tamron 70-300, f5.6 @ 300mm. The background to the left of the subject is just as soft and blurry as your examples, and the background on the right is similarly blurry, and getting a constant color across the background would have only required a different shooting angle from me, not any sort of fancy gear.

The other added bonus of a longer lens is that you don't have to get so close to and risk spooking the wildlife.

Answer 5

Question 3: Is it possible that gels are involve in the creation of such complementary colors?

Possible? Sure. The bluish cast to the backgrounds (presumed to be plant matter lit by skylight), and the blue rim lighting in the first and last pictures contrasted with the neutral tone of the fill lighting hints that the fill was warmer than the ambient. After white balancing for the fill, the ambient becomes cooler, giving the images more of a complementary blue-yellow dynamic than they would have otherwise.

This could be intentional, with a warming gel on the flash, or could simply be a result of using diffusion materials that have this effect.