Tilting Lens Port - Developed by ILM for Star Wars

[Riskbreaker]

Is anyone familiar with the "tilting lens port?" This is something John Dykstra helped develop for the original Star Wars as part of his Dysktraflex system. As far as I understand, it allowed the visual effects team to maintain perfect depth of field (focus, essentially) on the model miniatures (the ships) as they filmed them from great distances and then zoomed in for close-ups.

I'm looking for better information about this system, what it was, how it worked, etc. I've come up empty with my previous searches and was hoping some good, old fashioned RPF geekery could put me over the top. Thanks.

 

[Ozymandius]

I'm somewhat familiar with it.

It was the first computer controlled camera system wherin the computer would fully control the dolly, tilt, zoom, and focus of the camera. It was revolutionary because it allowed the crew to create moving FX shots, wheras before they could only composite models against a static background.

Also because the rig could duplicate the same shot over and over, it allowed them to do multiple passes over a model, thereby getting a seperate exposure for each individual element. For example they would do the first pass of an x-wing in silouhette to get the cut out shape for the template. Then they would do a well lit beauty pass with the model to get the intricate details of the craft. And then they would do a practical lighting pass in dim light so that they could get good exposure on bright elements like the engine glow and other light sources. These three images would then be composited on top of one another to create a single complete image that was then composited onto the moving background.

Did any of that help?

 

[Riskbreaker]

Yeah, that's helpful. I had a pretty good understanding of the motion control system.

What, specifically, though is the "tilting lens port?"

 

[vistaVision]

It's nothing new, Dykstra and crew didn't invent it, but they did create custom equipment to make this work with their various camera rigs. You will find a pretty good explanation here: View camera - Wikipedia, the free encyclopedia

The entire thing is a good read, but if you scroll down to the "Tilt" heading, you will find the principle of what ILM was doing explained.

 

[Riskbreaker]

Thanks, VV. Very helpful.

 

[erredois]

1- Maybe you are looking for Scheimpflug effect:
https://www.youtube.com/results?search_query=Scheimpflug+camera

2- Also, some tilt shift lenses (?)
https://www.youtube.com/results?search_query=tilt+shift+lens+camera


2- https://www.youtube.com/watch?v=4QJr2FvQlqY
at 1:30 min
this is early days of Dykstraflex

 

[anamorphicWayne]

You might find this interesting.

http://videoandfilmmaker.com/wp/index.php/features/a-look-back-at-star-wars-old-school-vfx/

I found this in an AC.

"With our system, motion of camera and subject continues during exposure, just as in live-action photography. This is where the 300 shutter creates a problem. When the ship being photographed becomes small and its motion-per-frame is greater than a quarter of its overall size, it becomes a smear. In this situation, there is a happy medium of shutter-angle setting which makes the ship image apparently sharp and reduces strobing, minimizing that annoying syndrome as much as is possible. Once our shutter angle is chosen, we can deal with focus. The follow-focus device is built into the camera, and includes a tilting lens board for tailoring depth of field on tight shots. It runs off the same time base as the motion control motors. It can be initialized (establishing base point for focus calculations) and will change directly with the camera moves on the track. Or it can be individually programmed in cases where the camera subject distance is determined by something other than the camera track (if the camera boom is used or the subject is mounted on another track which moves it nearer to or farther from the camera during the shot)."