Designing a Monster Drop
Small drops are simple.
Putting aside the day|night aspect and production of the physical drop, both of which can complicate matters, composing anything less the 50 feet long is easy peasy. 50 to 90 feet long adds a bit more work due to the increase of perspective distortion that can cause the sides of the image to fall into the uncanny valley. Although, this is easy to fix if you know what you are doing. 100 plus feet is where things get complicated.
Any drop that is 100 to 150 feet long is going to wrap around the set on two sides, covering two directions of view, which means you now need to maintain your horizontal perspectives for two directions. Accomplishing this can be tricky because you will need to make multiple panoramas from the same source files and merge them somewhere in the middle. This can become especially complicated with city views due to the need for buildings to render properly. However, 165 plus feet is where the rubber really meets the road since the drop is now wrapping around three, or maybe four, sides of the set.
On a recent production in Utah, we were hired to produce a custom 20 x 193 foot backing that would act as the view on three different sides of the set with the flanks wrapping around the fourth side. For a drop this big, it is easy to accidentally skew areas within the view from the position they would be in if you were viewing it on location. Likewise, given the many different styles of panoramas, ending up with an image that is either stretched or compressed is possible as well, something you may not realize until after you already put a lot of time into making it. So, to avoid this, you really need to think about this image not as a photograph but a design.
My first step was to create a 30 x 220 foot Photoshop file. With the lens I was using, the image would fill 25 feet of the height, for a 1:1 scale, with the rest being additional sky that would be added in post. This, plus the additional width, would give a decent amount of breathing room in the final image in case the DP wanted to push the view a little further back. Looking at the set plans, I then calculated the position and length of each four curves and three sides in the backing. Using guide lines in Photoshop, I marked the position of each of these, along with the center of the central view, in the file.
Next, I created three rectilinear panoramas from my source images, representing each direction of view, and placed them into the file. To ensure I positioned them as accurate as possible, I used location pics I captured with my iPhone as reference. After this, I could then mark (arguably the most important aspect of any backing) the position of the horizon line, and use that marking to mark the top and bottom crop lines for a 20 foot tall drop. Now, one of the downsides of rectilinear panoramas is the tendency to flare the edges above and below the view. For smaller drops, this may not be much of an issue, but with larger drops it will distort the view in these areas giving an inaccurate rendering of the scene.
To correct for this, I used the source files to create three additional panoramas for the center of the two inner curves and the right flank of the image utilizing a different panorama style then rectilinear. The left most side of the image was created from a different set of source images altogether (approximately 100 feet away) allowing me edit out the construction equipment in the view. After dropping these four additional panos into the file, I used Photoshop tools to blend everything together. At this point, I was finally able to drop in a new sky and clean up the ground from the construction.
Insofar as a timeline, I flew into Salt Lake City Tuesday July 15th, photographed the backing on the 16th, had a first draft file end of day on the 17th, I was back home on the 19th for my daughter’s 1st birthday party, file went to print end of day of the 21st and backing arrived on set in Utah August 5th, just four weeks from shoot date.