Jump to content


Photo

Of Giants and Miniatures


  • Please log in to reply
6 replies to this topic

#1 Joe Giambrone

Joe Giambrone
  • Basic Members
  • PipPip
  • 98 posts
  • Director

Posted 26 July 2008 - 06:11 PM

Hello,

I've been talking to various DPs about how they scale images, and have found various formulae for this regarding frame rate, distance, etc.

For example, a 1/12th scaling you shoot the sqrt 12 * framerate (24) to arrive at 83 fps for a desirable upscale (slowing) of the element you want to look 12 times bigger.

Are there people here who have actually done this in practice on professional shoots?

Can you elaborate on the dirty details involved in making it look as real as possible?

It was suggested to shoot 10mm focal length for the scaling, as you get a lot of depth of field.

In matching the small blown up object (in front of a green screen) to the background plate, I am very concerned with a similar field of view and depth of field characteristics. Those would seem to be the hard part of the deal.
  • 0

#2 Jim Keller

Jim Keller
  • Basic Members
  • PipPipPipPip
  • 290 posts
  • Producer
  • Fresno, CA

Posted 28 July 2008 - 04:21 PM

I've only ever done miniature work for still photography, so I can't address the frame rate issues, but for still photography I'm not a fan of using shorter lenses for models. Audiences perceive the fisheye and it feels like a model. Rather, I prefer to use a longer lens with lots and lots of light (improving my depth of field by letting me use a smaller aperture).
  • 0

#3 Chris Keth

Chris Keth
  • Sustaining Members
  • 4427 posts
  • 1st Assistant Camera
  • Los Angeles

Posted 28 July 2008 - 05:08 PM

I have to agree with the disapproval of using wider lenses. Use the lens to achieve the perspective and angle of view that you want. Then light to the stop that will give you the depth of field you want. That will look more convincing than going much wider on the lens.

As for the framerate, that is the same "rule" I have heard. I have never tested it myself, though. I know there are quite a lot of books about Ray Harryhausen's work and about the effects work for Star Wars. Perhaps you can find some good answers there.
  • 0

#4 Stephen Williams

Stephen Williams
  • Sustaining Members
  • 4708 posts
  • Cinematographer
  • Europe

Posted 28 July 2008 - 05:39 PM

I have to agree with the disapproval of using wider lenses. Use the lens to achieve the perspective and angle of view that you want. Then light to the stop that will give you the depth of field you want. That will look more convincing than going much wider on the lens.

As for the framerate, that is the same "rule" I have heard. I have never tested it myself, though. I know there are quite a lot of books about Ray Harryhausen's work and about the effects work for Star Wars. Perhaps you can find some good answers there.


Hi,

The framerate formula works fine, I have used it many times. I use the same lens for scale models & full size, then you can move the camera with a motion control rig doing a matched but scaled move.

Stephen
  • 0

#5 Leo Anthony Vale

Leo Anthony Vale
  • Basic Members
  • PipPipPipPip
  • 2010 posts
  • Other
  • Pittsburgh PA

Posted 29 July 2008 - 02:44 PM

I've been talking to various DPs about how they scale images, and have found various formulae for this regarding frame rate, distance, etc.

For example, a 1/12th scaling you shoot the sqrt 12 * framerate (24) to arrive at 83 fps for a desirable upscale (slowing) of the element you want to look 12 times bigger.

Are there people here who have actually done this in practice on professional shoots?

Can you elaborate on the dirty details involved in making it look as real as possible?


quite awhile back, I came across a circa 1930 SMPE Journal ( the T for telvision had yet to be added)
in which it was shown how that formula for miniature speeds was derived from the formula for the speed of falling objects based on gravitational acceleration. Unfortuneately I can no longer remember the proof.

Certainly use the same lenses that you would use for the live action, else the miniature shots will stick out. Unlike the other responders I would use wide angles for both.
Suppossedly michael Chapman has said that long lenses are "...elitist, immoral, and possibly even corrupt".

Adding atmospheric perspective (haze) will help, a light diffusion or fog filter or a lot of cigerette smoke will help.
  • 0

#6 Joe Giambrone

Joe Giambrone
  • Basic Members
  • PipPip
  • 98 posts
  • Director

Posted 29 July 2008 - 08:02 PM

Thanks for the answers.

"Adding atmospheric perspective (haze) will help, a light diffusion or fog filter or a lot of cigerette smoke will help."

It on the water, so there will be some water spraying involved.

Is there a web depth of field chart where I can study the various field of view and aperture possibilities?

I may use pretty wide lenses for both the small and large, but I don't want to be locked into that configuration for all those shots.
  • 0

#7 Jim Keller

Jim Keller
  • Basic Members
  • PipPipPipPip
  • 290 posts
  • Producer
  • Fresno, CA

Posted 31 July 2008 - 01:21 PM

Thanks for the answers.

"Adding atmospheric perspective (haze) will help, a light diffusion or fog filter or a lot of cigerette smoke will help."

It on the water, so there will be some water spraying involved.

Is there a web depth of field chart where I can study the various field of view and aperture possibilities?

I may use pretty wide lenses for both the small and large, but I don't want to be locked into that configuration for all those shots.


I use the depth of field guides published by the ASC. Remember, though, that the "same" depth of field on different length lenses does, in fact, have a different look, so I suggest testing to be sure you like the result (you can do this on a still camera with the same size chip as your production camera / same size negative as your production camera) before doing the full production.

You'll want to use more mist than you think you need, because the audience will perceive the mist as atmosphere first and mist second. Bear in mind that water doesn't miniaturize well, so, again, you'll want to run tests.
  • 0


Abel Cine

Metropolis Post

Wooden Camera

Willys Widgets

Ritter Battery

CineLab

Opal

rebotnix Technologies

Broadcast Solutions Inc

CineTape

The Slider

Tai Audio

Visual Products

Rig Wheels Passport

Technodolly

FJS International, LLC

Aerial Filmworks

Gamma Ray Digital Inc

Paralinx LLC

Media Blackout - Custom Cables and AKS

Glidecam

Media Blackout - Custom Cables and AKS

CineLab

Wooden Camera

Gamma Ray Digital Inc

Glidecam

Opal

Abel Cine

CineTape

Technodolly

Tai Audio

Willys Widgets

Rig Wheels Passport

Aerial Filmworks

rebotnix Technologies

Ritter Battery

Visual Products

Broadcast Solutions Inc

Metropolis Post

Paralinx LLC

FJS International, LLC

The Slider