How to Use Double Exposure For iPhone, iPad and iPod Touch Double Exposure iOS Blocked Unblock Follow Following Apr 25, 2016

Double exposure photography is the technique of layering multiple photos on top of one another creating surreal photos without the need for post processing. While double exposure photography was traditionally limited to film and high end SLR cameras, this tutorial will show you how to shoot great double exposures using Double Exposure for iPhone, iPad and iPod Touch. Exposure Compensation Before learning to shoot double exposures, it’s important to have an understanding of what exposure is and how to control it using exposure compensation. So what is exposure? In photography, exposure is the amount of light per unit area (the image plane illuminance times the exposure time) reaching a photographic film or electronic image sensor, as determined by shutter speed, lens aperture and scene luminance. Exposure is measured in lux seconds, and can be computed from exposure value (EV) and scene luminance in a specified region. — Wikipedia In other words, exposure is the amount of light your camera’s lens allows into your photo. When a photo is too bright (too much white), it is considered “over exposed.” When a photo is too dark (too much black), it is considered “under exposed.” A perfectly exposed photo is a photo with just the right amount of light. Your iOS device’s camera has the ability to automatically calculate the correct exposure for your photo. When shooting double exposures, you will sometimes want to purposely under or over expose your photos to achieve a particular effect. In Double Exposure, this can be done using the exposure compensation picker. By sliding the picker to the left or right, the exposure value calculated by your device’s camera can be offset.

An example of the same subject with different exposure compensation values

The same way distance is measured in feet or meters, exposure is measured in a unit referred to as a stop. The exposure compensation picker allows you to offset exposure by 1/3 stop increments similar to the way a digital SLR camera would. How to Shoot a Double Exposure To create a double exposure, you’ll first want to line up your first photo. Set your exposure value using the exposure compensation picker. In this case, the photo is over exposed by 1 1/6 stop blowing out the background giving it a white colour. In film and digital photography, once film or a pixel becomes white, it cannot be brought back to a darker colour. The sections of the photo which are still dark will be used as the area to be rendered to in the next photo. Snap your photo using the little shutter button. This is like taking a photo with a film camera, but not winding to the next frame allowing you to shoot your next photo on top of it.

In this sequence, the little button is pressed for the first photo and the large button to finish off with the second photo. The live preview is hidden in the third shot to see the second photo in its entirety. Take note of the how the white background from the first photo masks the second image. Also take note of the exposure values. The first photo is over exposed by +1 1/6 to blow out the background and the second photo is under exposed by -1/6 to create a silhouette with the leaves.

For the second photo, the exposure value is lowered. The bushes are shot sideways to blend with the subjects face from the first photo. Since the background was white in the first photo, any sections of the second photo overlapping the white from the first will be masked. When lining up your second photo, the “live preview” can be shown and hidden using the Live Preview Button making it easy to see the current photo being shot and lining up your composition. Additionally, the individual photos can be saved when shooting a double exposure by toggling the Individual Save Button (The third button on the top from the right). Shoot your second photo by pressing the larger shutter button. This is the equivalent to shooting a photo on a film camera and winding to the next frame to start fresh for your next photo. Double Exposure is not limited to double exposures. Triple, quadruple, quintuple… even centuple (100) exposures can be taken. These are normally referred to as multiple exposures. Since exposure values are accumulated when shooting multiple photos, it’s normally a good idea to keep your exposure levels low to avoid over exposing. Using Photos From Your Library In addition to using your iOS devices camera, photos from your library can also be used. To do this, open your photo library and navigate to the photo you would like to use. After selecting the photo, you will be brought to the photo viewer. Here you can view your photos or use them in the editor menu by pressing the blue button at the bottom which looks like the shutters. To use a photo from your library, navigate to the photo in the photo picker, select it, then in the viewer, press the blue button which looks like the two shutter buttons (Bottom of the second screenshot). This will allow you to edit your photo as well as use it in a multiple exposure. From the editor menu, photos can be scaled, rotated and moved with pinch, twist and drag gestures. Exposure can be modified with the exposure compensation. The same shutter button options can also be used as if the photo was being taken with the camera. In this sequence, a triple exposure is made with three photos from the library. The first two photos have an exposure compensation value of -2 applied. Since the photo is shot with a black background, the appear faded. The last photo has no exposure compensation applied to it. Applying Filters to Your Photos By pressing the filter button on the bottom right of the screen, you get a live preview the filters applied to your current photo. Adding filters to your multiple exposures will give your photos a unique look. Select your filter and shoot your photo similar to the way filters work with the native iOS camera.

Different filters applied to the same photo.