image Editing

transitions set the rhythm of the journey.

SMOOTH TRANSITIONS AND HARD CUTS

In 360° film, the projection surface is both fundamentally much larger than in conventional film and contains more information. The story is told as spaces strung together and not in a sequence of framed shots. A cut in a head-mounted display (HMD) is not only a change of setting or context, but of an entire environment. Therefore, the audience perceives the change much more intensely and with more unpredictability. This reception is explained in the factors below.

Viewing direction
360° films require users to turn their bodies around in order to follow the panorama-wide events. This additional degree of freedom is only possible when the user is sitting on a swivel chair or standing. Unlike classical films, scene "cutting" in VR introduces new challenges as we bring users from one space into another. How can we guarantee the story's feeling of continuity despite an intensely perceived transition? Observations from test screenings and interview evaluations show that orientation is a key component to this question, especially for audiences that are not yet used to viewing 360° films through an HMD. 

If the story flow is to be maintained, we recommend directing the viewer's orientation during the transition and planning the scene alignment for both before and after a cut in order to create a smooth and effective transition. Specifically, the points of interest at the end of a shot are aligned with the those in the subsequent shot; ensuring that the viewer remains focused on the key story elements. Depending on the design approach, free or dead spaces can be offered within planned sequence so that the explorative quality of the 360° film can help orient and give the viewer their own individual experience.
This approach should already be included in pre-production. Jessica Brillhart has written articles on this that are worth reading:

• Direction of Attention

• Holding attention (engagement)

Rhythm 
The rhythm of the 'cut' should be adjusted based on the audience's experience or familiarity with 360° films as well as the final medium such as a HMD, desktop or mobile screen. Additionally, user orientation plays an important role for the rhythm. The faster the cut, the closer the points of interest should be placed at the end of one shot to the beginning of the next. This prevents viewers from having to search for the action connection by turning their heads and bodies. Therefore, what is achieved in 360° film with body alignment is done in conventional film with eye movement. Mad Max Fury Road is an illustrative example that uses rhythm and points of interest in centre framing.

Commonly used transitional forms

Based on a wide variety of 360° productions viewed during the project, types of transitions are as follows.

Fade to Black oder White
This classic transitional form is reminiscent of the raising and lowering of the curtain in the theatre. It can also be interpreted as the end of a scene or a chapter. With this transition, the points of interest do not necessarily have to coincide, as the settings are interrupted with a neutral black or white fadeout. It is possible that in the new scene users must first search for the point of interest. This adjustment can be used as a creative element. If the new point of interest is outside the user's field of view, i.e. if it shifts by more than approx. 110° horizontally and by more than approx. 70°, then an additional indication such as an spatially placed acoustic signal can be helpful to reorient the user.

Cross-fade
This connects the two scenes by crossfading. It gently guides the viewer from one space to the other. This approach of using a montage based on points of interest can be seen below.

Hard cut
This variation has its pitfalls. The filmmaker should be sure that the viewer looks at the intended point of interest when changing the scene to guarantee the correct user orientation after the cut. This type of editing can be both combined and supported by the rhythm of the music, as is done in conventional film.

Of course, the described cut variations can be combined in the same film, as the following example shows.

Jump Cut
A jump in the time plane to a cut in the same shot. In principle, this works in 360° films. In principle, this works in 360°film.

Animation
Transitions can also be created through elaborate animations. A good example of this can be seen in iPhilip (Hulu VR, 2017).

Tracking shot
In this form of transition, you 'drive' into the space of the next shot. This transition works particularly well with journeys, as most users are oriented in the direction of the movement. They want to see where the journey is going, as if they were at the steering wheel.

Working at the editing suite

We recommend installing a head-mounted display in the editing suite as earily as possible. This makes it easy to control and repeatedly visualise the project as well as precisely design the transitions. With Premiere Pro, for example, the software monitor can be displayed directly in the headset with the help of GoPro VR plug-ins. In addition to 'internal' testing, we also recommend screening and testing with external audiences. The user feedback can provide valuable clues for precise and well-perceived image mounting. User observations should focus on orientation, alignment, rhythm, and attention span.

Conclusion
Editing is also an effective way to advance narration and user engagement in 360° film. However, we can only partially draw on this knowledge in classic film. Since the field is young and there is little experiential knowledge readily available, we advise to plan, test and to include the experiences of the test audience in the work process. 

Further Links
Editing 360°Film in Premiere Pro