The Living Pictures captured with the LYTRO ILLUM can be refocused, just by tapping. This ability to refocus is remarkable, but it does have limits — what we call the refocusable range — for every picture. The refocusable range comprises all the points brought into relatively sharp focus after a picture is captured.
The refocusable range is made up of two component ranges: the near refocusable range, which is closer to the camera, and the far refocusable range, which is further away. Each offers a spectrum of relative sharpness, depending on the depth who which the image is refocused.
In the illustrations below, the brighter the shade of the blue or orange band, the sharper objects at that distance will appear when refocused. The brightest band in each component range is its peak — where objects will appear sharpest when refocusing.
The refocusable range varies widely, depending on the zoom and focus positions of the camera when a picture is captured.
Effective use of the refocusable range and the depth composition features on the LYTRO ILLUM is the key to creating extraordinary Living Pictures. To find out how to best leverage these tools, visit training.lytro.com for in depth education and training.
The Depth Assist Bar appears as a column near the right edge of the screen. The orange and blue bands within the bar show where the current refocusable range falls in terms of distances from the camera. The objects within that range are the ones that can be refocused on after the Living Picture is captured.
Each of the colored bands represents one slice of the depth within the refocusable range, called Depth Steps. The brighter the color of a Depth Step, the sharper the objects at that distance will appear when it is refocused.
The distances are measured from the sensor plane symbol, , visible on the right side of the camera’s exterior. While the measurements are mostly accurate, they are not perfect. Think them as useful guide, there to give a good sense of where the refocusable range is located.
When the lens is set to the light field hyperfocal position, the refocusable range extends from optical infinity (the horizon) to a close focus distance. More specifically, objects at or near optical infinity are at a depth near the peak of the far refocusable range, while the entire near refocusable range extends closer to the camera.
The close focus distance depends on the current focal length of the camera. At wide angle, the close focus distance is approximately 25cm from the sensor plane. At maximum zoom, the close focus distance is approximately 10m.
When looking at the live view, the shallow depth of field is due to the f /2.0 main lens. There is much more in the refocusable range than what appears sharp in the live view. The optical offset plots the optical focus position used in the live view (and for autofocus) to the refocusable range — and can be adjusted to suit the style of Living Picture being captured.
When the optical offset is at the default setting, objects at the peak of the near refocusable range will appear sharply focused in the live view. This means that a Living Picture can be refocused on whatever looked sharp in the live view when it was taken, as well as on objects further away, since most of the refocusable range will fall beyond that point.
Depending on the style of photography and the subjects being shot, it may be advantageous to relocate the optical offset position. As an example, when shooting landscapes, set the optical offset to the peak of the far refocusable range. Then, when composing a shot by focusing on a distant object, most of the refocusable range would be available for closer objects.
To adjust the optical offset, add the Optical Offset icon to the Menu Bar (see Rearrange Menu), then tap it. The Menu Bar will be hidden, and a depth scale will be displayed.
Bands in shades of blue represent the near refocusable range, and bands in shades of orange represent the far refocusable range. The current optical offset position is indicated by a white band (the default position is -4). Rotate the front dial to relocate the optical offset closer or further away in the refocusable range.
To close the depth scale, unhide the Menu Bar by swiping left from the right edge of the screen. The optical offset will remain at the new setting until it is changed using these same steps.
Spot Depth Feedback allows you to check the distance of the object at the center of the live view. Press the Lytro button halfway to activate it. A light blue band will appear on the Depth Assist Bar, representing the distance of the object from the camera. It is then easy to see if the object falls within the focusable range, indicated by the orange and blue Depth Steps. Activating Spot Depth Feedback does not affect the focus of the camera.
The LYTRO ILLUM offers live, interactive depth analysis in the form of the Depth Histogram and Depth Overlay. Both provide feedback on where subjects fall relative to the refocusable range. To activate them, fully press the Lytro button.
The Depth Histogram consists of bands extending out to the right of a depth scale. Bands in shades of blue represent the near refocusable range, and bands in shades of orange represent the far refocusable range. The more there is available to refocus on at a given depth, the further the band beside it will extend to the right.
Glancing at the histogram can tell if you have a substantial subject within the refocusable range. To maximize the impact of refocusing, it is ideal to have a significant histogram wave in both the near refocusable range and the far refocusable range. Waves outside of the refocusable range correspond to objects in the background or foreground that can not be refocused.
The Depth Overlay provides the same kind of information as the Depth Histogram, but displays it as an overlay on objects in the live view. Objects that fall within the near refocusable range are edged with blue. Objects that fall within the far refocusable are edged with orange. Instantly see whether there is enough subject matter in each of the ranges to provide good refocusing possibilities.
Like the more familiar exposure bracketing, focus bracketing causes the camera to take a series of pictures each time the shutter button is pressed. But instead of varying the exposure between each picture, the camera varies the focus. That means the refocusable range is shifting, too, so there is a better chance of capturing a picture with great possibilities for refocusing.
The change in focus between each picture is expressed in Depth Steps. Choose the number of Depth Steps, from 1 to 10, between each picture. One can choose 3 or 5 pictures.
To use focus bracketing, add it to the Menu Bar (see Rearrange Menu). Then activate it and set the number of pictures that will be taken and the number of Depth Steps between each picture. For help setting those parameters, see Applying focus bracketing.