Multiple exposure

Multiple exposure means superimposing several photos to create a completely new, different image. The name origins from analogue photography, where the same part of a film roll was exposed several times with different image sections to achieve this effect. In digital photography, multiple exposures are created by combining several image files with software, either directly in the camera or afterwards in image processing.

The first example image shows how multiple exposures can unexpectedly transform a very simple subject into a creative photograph. It shows a radiator, shown here in its entirety. With the idea of having the parallel ribs intersect to form a pattern, I switched on multiple exposures in my camera and took two photos with a smaller crop and the camera rotated in different angles. From these, the camera produced the photo shown at the very top.

You can already guess from the first example: The possible combinations and variations are unlimited, and the results can be surprising. If you enjoy it, you can experiment with it indefinitely. That way, you quickly get a lot of shots and two more challenges:

• sorting out and deciding which photos are the best – not so easy with unusual, uncommon image effects
• to somehow influence the multiple exposure in a certain direction if you don't want to be satisfied with random results.

To illustrate this, here are two more multiple exposures of the same radiator, this time from four individual shots – once rotated only marginally, once rotated more against each other more than before. In the upper one, I also varied the direction of view onto the radiator, so that the dark spaces in between were differently intense.

If you expose the same area several times on a conventional film, the final photo will become brighter with each additional exposure, because additional light comes in each time. Two normally exposed shots together result in a rather overexposed one. This can be desirable and can be cleverly used, for example, to achieve a white background – or be unfavorable. At some point the result of many multiple exposures will be uniform white.

If you want the multiple exposure to appear similarly bright as photos taken individually, each individual shot must be exposed darker. If you turn on multiple exposures in a camera, there will be a choice for exposure compensation, then you don't have to worry about it.

If you want to uderstand the logic behind: For two exposures you need a -1.0 correction by one exposure value, for four frames a -2.0 correction by two exposure values, etc., because one exposure value always means the doubling or halving of the amount of light.

The photo shown at the beginning was taken with exposure compensation, here another multiple exposure without exposure compensation. You can already see in two shots how the multiple exposure is clearly brighter.

The more shots you combine, the less each one contributes to the final result. You should bear this in mind if you want details from the individual images to be recognisable. The next examples of a church tower against a uniform grey sky show the effect quite clearly. People become blurred, ghostly figures in just two shots.

The more images you combine and the greater the differences, the more you will get a random, difficult to recognise photo. Here is a spur-of-the-moment example of this, a multiple exposure (with exposure compensation) of six images. Enlarge the picture by clicking on it to see details.

The plate with lemons, the view out of the window onto another house as well as the stripes of the radiator, which I have already used above, easily catch the eye. Likewise a plant with long, slender leaves. The fifth and sixth subjects are more difficult... a landscape with ocean waves, you can see them in the upper right quarter. And then there is a wall clock, below the lemons you can see its dial.

OK, it's not a particularly profound composition, but it shows nicely how individual components are still recognisable or can only be faintly guessed – this enables complex, multi-layered images that challenge the viewer to look at them.

It can become quite complex and difficult to influence a multiple exposure in a desired direction when very different images are mixed. On the other hand, it is a superimposition according to simple rules. If you watch carefully which parts will be superimposed, the result will not be a pure coincidence.

Identical image parts remain clearly recognisable | By ”identical image parts“ I mean sections of the image that are the same in all combined photos. Here is a multiple exposure, taken in a pedestrian tunnel. The camera was mounted on a tripod, so the walls where no pedestrian walked through the picture look like a normal photo; the multiple exposure is a superimposition of identical pictures there.

If the camera is not fixed exactly, there would be an effect similar to camera shake with long exposure times, but the subject would remain recognisable.

Uniform areas let other images shine through better | The next example photo shows this effect. While experimenting in a park with autumn trees, I came to the idea of interspersing the shape of a bare tree with the shapes and colours of autumn leaves. One shot of the multiple exposure is the silhouette of a tree against cloudy sky; the second one a detail showing mainly autumn leaves on a tree,. The autumn leaves of the second shot are visible everywhere; more clearly above the dark silhouette of the bare tree than against the bright sky.

So far I have presented two variants – multiple exposures with and without exposure compensation. They differ in how bright the result turns out, but they are more or less recognisable superimpositions of all images everywhere.

Since the multiple exposure is created in image processing software, other rules of the game are conceivable. As an example and suggestion, I show two that my Nikon camera (Z6 II) has; other models may have fewer or even more and fancier ones. If your camera doesn't offer anything like this, there is always the alternative to image processing on the computer, more on this below.

Picking the brighter parts | The multiple exposure shows only one of the photos used at each spot - the one that is brightest there. Look at the next example photo to verify it: a light car with dark windows as well as a wall covered with red autumn leaves. Compared to the dark windows, the red foliage is lighter - only the foliage is visible. The other way round on the light-coloured body, only the shape of the car appears. And where both photos have similar brightness, the result is a colourful mixture, similar to an overlay.

Picking the darker parts | This is the other way round: The darkest photo prevails at each point of the finished picture. Here illustrated with a church tower against a much lighter, cloudy sky. The second shot of the pavement with autumn leaves was darker than the sky, so it appears around the church steeple. The tower, in turn, was darker than the foliage and paving stones, so it is still clearly visible in the picture. However, it is interspersed with the even darker joints of the paving.

So these variants also produce mixed, combined images, but individual elements of the picture assert themselves more clearly, you don't get the blurred, ghostly effects.

Wenn du mit Mehrfachbelichtungen experimentieren möchtest, sollte ein erster Gang in die Kamera-Menüs oder die Anleitung führen, um nachzusehen, ob deine Kamera Mehrfachbelichtungen unterstützt. Das ist nicht selbstverständlich, meine Beobachtungen sind:

• Nikon und Canon-Systemkameras bieten sie an, mit Ausnahme der kleinsten Einsteiger-Modelle.
• Sony-Kameras scheinen sie nicht beigebracht zu bekommen, auch die fortgeschrittenen Modelle nicht.
• Bei Kompaktkameras scheinen Mehrfachbelichtungen nicht üblich zu sein.

Bei Nikon und Canon gibt es ein Menü Mehrfachbelichtung, hinter dem sich die weiteren Einstellungen verbergen, an beispielhaften Modellen habe ich beobachtet:

• Anzahl der zu überlagernden Bilder
• Ob die Kamera Mehrfachbelichtungen wieder ausschalten soll, wenn eine Folge komplett ist.
  Achtung: Unbeabsichtigt eingeschaltete Mehrfachbelichtungen verderben deine anderen Fotos.
• Wie die Bilder überlagert werden sollen:
• mit Belichtungsausgleich (Durchschnitt)
• ohne Belichtungsausgleich (addieren)
• die hellsten oder dunkelsten Bildstellen setzen sich durch
• Ob alle Fotos für eine Mehrfachbelichtung auch als eigene Dateien gespeichert werden sollen
• Evtl. lässt sich ein beliebiges vorhandenes Foto auf der Speicherkarte als Anfangsbild für eine Mehrfachbelichtung auswählen.

If you want to experiment with multiple exposures, a first step should be to check the camera menus or the manual to see if your camera supports multiple exposures. This is not a given, my observations are:

• Nikon and Canon system cameras offer them, except for the smallest entry-level models.
• Sony cameras don't seem to be taught how to do multiple exposures, not even the advanced models.
• Multiple exposures do not seem to be common in compact cameras.

Nikon and Canon have a menu Multiple Exposure with further settings behind it, on sample models I have observed:

• Number of images to be superimposed
• Whether the camera should switch off multiple exposures again when a sequence is complete.
• Attention: Unintentionally switched on multiple exposures will spoil your other photos.
• How the images are to be superimposed:
• with exposure compensation (average)
• without exposure compensation (add)
• the brightest or darkest parts of the picture prevail
• Whether all photos for a multiple exposure should also be saved as separate files
• It may be possible to select any existing photo on the memory card as the initial image for a multiple exposure.

The same effect as with multiple exposures from the camera can also be achieved in image editing programmes on the computer, with advantages and disadvantages. The prerequisite is that you are familiar with more advanced functions, specifically how to create, fill and overlay layers. And of course you need to have an image processing programme that can handle several layers.

Advantages of a combination on the computer are:

• You can control the overlay better and more delicately than in the camera:
• select and deselect any photos
• adjust the mixing ratio yourself
• Select the blending method - with the four variants shown above and whatever else the software developers have come up with.
• move images against each other
• edit images combined in the multiple exposure beforehand
• combine any photos from your collection, also from different places and dates of shooting.

The disadvantages of a multiple exposure on the computer are:

• It helps immensely to see the result of a multiple exposure immediately and on the spot. Only then can you see if you have taken the right pictures at all.
• You sit at the computer in front of the monitor... If, like me, you enjoy working with the camera and the subjects on location, you have another strong argument for multiple exposures directly from the camera.

• Set your camera to also save the single shots of a multiple exposure.
• Work with multiple exposures directly in the camera and shoot until you have a result in the camera that you like. This will ensure that you have all the appropriate single exposures.
• Afterwards, if you are not completely satisfied, you can create a final image on the computer from the individual shots, with any correction you may want to apply.