[ricardo]

when your keyboard is faster than your mind - I'm a big fish here...

[jfrancis]

Just to really confuse things...



Frames are not points in time. Frames are periods of time. It's not even meaningful to use the phrase at frame 1. Saying at frame 1 is like saying at September.

http://www.digitalartform.com/archives/ ... _blur.html

http://www.digitalartform.com/motionBlur.htm

[darinh]

Wow this is an old thread!,

I don't claim to be an expert but there is a huge difference between the way an SLR film camera and a motion picture camera capture an image.

Still camera's usually use a diaphram shutter which dilate to the size of the lens and then retract depending on the exposure time, obviously motion blur will occur either with fast or slow moving objects depending on the time the object is exposed.
Motion picture cameras use a continuously spinning rotating disc shutter (a mirror) that alernately expose a frame of film or reflect the view through the lens back to the viewfinder to the camera operator. Motion blur can be controlled by adjusting the shutter angle which is usually defaulted at 180 degrees (imagine the circular mirror lying on it's side allowing maximum exposure).
at each 1/24th of a second a frame of film is only really exposed about half the time since the shutter will be reflecting the image back to the viewfinder for the other half. This translates to an exposure time of 1/48th a second sometimes rounded up to 1/50th of a second

If you exposed more frames per second you get less motion blur since those frames would be recieving half the amount of light as a 24fps sequence, you could adjust your shutter angle to compensate for this and perhaps your film stock.

So the shutter angle is the most important factor affecting motion blur in motion pictures not frame rate. In CGI motion blur is faked by sampling inter frames, it's not true motion blur since the image is not being exposed like in film. The obvious exception is maxwell of course!.

Also exposing an image for a long period of time is not time lapse, that is time exposure, time lapse is imagery captured at a slower rate than normal then played back a higher rate, this has also been called under-cranking.
For motion to appear smooth and not like stop motion you would need to adjust the exposure time to match the time interval, to match film this would be half, so if you were shooting every 40 seconds you would need to expose the frame for 20 seconds for the motion to appear realistic and smooth.

[Mihai]

[jfrancis]

http://www.digitalartform.com/motionBlur.htm

[tom]

In fact, this thread didn't start to discuss how motion blur is happening in still and motion cameras. The question was easy and it was a plugin problem. Because in 3D applications, if you deal with time, you need to determine FPS first. For example if you set FPS 9999, it means 9999 frames means 1 second. So, when keeping the maxwell camera shutter same, if you change the FPS in application, it should affect the result. But didn't work then... and when I was trying to talk about this, people suddenly started to lecture on motion blur without reason. It was a plugin problem and nothing related to the difference between still and motion camera. The matter was definition of 1 second and it's almost over for me.