Alexander Sutton Hough Posted March 24, 2017 Share Posted March 24, 2017 I need to film some items falling and want to slow it down so it takes 15-30sec to travel from top to bottom of frame at a play back speed of 23.976fps. Any recommendations of what frame rates I should film in and what what high speed camera I should rent? Quote Link to comment Share on other sites More sharing options...
Max Field Posted March 25, 2017 Share Posted March 25, 2017 Depends how high up the items fall from. Should also precisely count how many seconds the falling lasts to get in the mathematical ballpark of what you want. Quote Link to comment Share on other sites More sharing options...
Sustaining Member Satsuki Murashige Posted March 25, 2017 Sustaining Member Share Posted March 25, 2017 First, figure out how many seconds (X) it takes for each item to fall though your frame in real-time. Then divide your screen-time of 30 sec / X = F. That is the factor (F) by which you need to slow down the motion. Last, multiply F x your playback rate of 24fps to get your required frame rate. For example, let's say it takes 2 sec for an apple to fall in real-time. 30 sec (screen-time) / 2 sec (real-time) = 15 (F). 24fps (playback rate) x 15 = 360fps. That's getting into Phantom territory for sure. Quote Link to comment Share on other sites More sharing options...
Michael Rodin Posted March 25, 2017 Share Posted March 25, 2017 And time of free fall in seconds is roughly 0.45 x square root of height in meters. It's physics, gt^2 = 2h :) Several hundred fps can be shot on many 16/35mm cameras, and it might end up cheaper than a Phantom. Quote Link to comment Share on other sites More sharing options...
Max Field Posted March 25, 2017 Share Posted March 25, 2017 This camera could get some work done if renting a Phantom is out of your budget. 1000fps at 1080p https://www.bhphotovideo.com/c/product/1159879-REG/sony_dsc_rx100_mark_4_digital.html Quote Link to comment Share on other sites More sharing options...
Sustaining Member Satsuki Murashige Posted March 25, 2017 Sustaining Member Share Posted March 25, 2017 I don't know about that particular Sony camera, but the budget slowmo camera Sony FS700 gets to higher framerates by line skipping and then eventually cropping. So it's really only useable up to 240fps. 480fps is quite soft and aliased, and 960fps is basically unusably soft. The newer cameras may have improved on this, but it's something to be aware of. Here's an FS700 test I shot about four years ago: https://vimeo.com/61947098 (starts @ 1:24). Quote Link to comment Share on other sites More sharing options...
Richard Perrine Posted April 5, 2017 Share Posted April 5, 2017 (edited) I've got a Fastex F4 16mm rotating prism camera from the mid 1950's or 60's. I've never run it...got the camera with a bunch of other stuff I picked up and since it's low speed is 500 frames per second I didn't think I would ever have to stop a bullet.....I think the top speed is some thing like 3000 frames. (would have to check the manual). Cables and books are there on how to use it and calculate exposure. Battery is not with the camera.....runs on something like 40Volts (another thing for me to check) If your interested..... About 100 lbs to ship. $400.00 plus packing and shipping (it is in it's own case.....I have some pictures I could send you). Located in Akron Ohio E-mail RBPerrine@att.net Edited April 5, 2017 by Richard Perrine Quote Link to comment Share on other sites More sharing options...
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