Liam Dale Posted August 1, 2010 Share Posted August 1, 2010 I wondering if anyone can tell me if there is an equation for maintaining the relative size of a primary subject during a zoom dolly (For instance: Starting 10 feet from the subject on 100mm lens - a camera dolly of 8 feet over five seconds requires an 80mm zoom to maintain the relative subject size in the frame). What is the relationship between the two movements? Thought game - would it be possible to link dolly to zoom mechanically? -Liam Quote Link to comment Share on other sites More sharing options...
Liam Dale Posted August 11, 2010 Author Share Posted August 11, 2010 Any ideas, guys? Maybe someone knows another visual effects board where I could ask? Quote Link to comment Share on other sites More sharing options...
Scott Fritzshall Posted August 12, 2010 Share Posted August 12, 2010 I don't know offhand whether that kind of equation exists, although I wouldn't be surprised if it did. Try pre-vising this out in a 3d program- set up a scene with correct proportions and a camera with the correct film back and lens settings, and play with moving the camera and zooming in. The way you'd automate these things if you were shooting is with a motion control rig. Quote Link to comment Share on other sites More sharing options...
Liam Dale Posted August 12, 2010 Author Share Posted August 12, 2010 Thanks, Scott. Could you recommend a capable 3d program I could track down without too much expense? -Liam I don't know offhand whether that kind of equation exists, although I wouldn't be surprised if it did. Try pre-vising this out in a 3d program- set up a scene with correct proportions and a camera with the correct film back and lens settings, and play with moving the camera and zooming in. The way you'd automate these things if you were shooting is with a motion control rig. Quote Link to comment Share on other sites More sharing options...
James Steven Beverly Posted August 12, 2010 Share Posted August 12, 2010 Thanks, Scott. Could you recommend a capable 3d program I could track down without too much expense? -Liam Blender is free, steep learning curve but there is a lot of tutorials and support and I've seen some beautiful work done with it. B) http://www.blender.org/ Quote Link to comment Share on other sites More sharing options...
Kar Wai Ng Posted August 12, 2010 Share Posted August 12, 2010 Thought game - would it be possible to link dolly to zoom mechanically? The Scorpio remote focus system has an optional motion encoder module to do this exact thing. There is a kevlar belt that goes along the dolly track, the encoder reads the position of the dolly on the track, and the MDR automates zoom and focus motors to maintain the same subject size (and focus!) And then there is full-fledged motion control... Quote Link to comment Share on other sites More sharing options...
Scott Fritzshall Posted August 12, 2010 Share Posted August 12, 2010 The Scorpio remote focus system has an optional motion encoder module to do this exact thing. There is a kevlar belt that goes along the dolly track, the encoder reads the position of the dolly on the track, and the MDR automates zoom and focus motors to maintain the same subject size (and focus!) And then there is full-fledged motion control... Oh, damn, I didn't even know that capability existed. Further evidence that I need to get on set more often... Quote Link to comment Share on other sites More sharing options...
Juha Leminen Posted August 22, 2010 Share Posted August 22, 2010 I wondering if anyone can tell me if there is an equation for maintaining the relative size of a primary subject during a zoom dolly (For instance: Starting 10 feet from the subject on 100mm lens - a camera dolly of 8 feet over five seconds requires an 80mm zoom to maintain the relative subject size in the frame). What is the relationship between the two movements? Thought game - would it be possible to link dolly to zoom mechanically? -Liam If get the dolly done and there is definition to spare, in post-production an adjusted image scale transformation. 1920 1080 and shotted about twice the definition it should be possible. Or would that just result in wrong effect though Quote Link to comment Share on other sites More sharing options...
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