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View Full Version : Blur Lenght film and tv ?



Drewitz
05-06-2003, 10:58 AM
I thought over the option blur length. It be based on cinema thus 1sec/24
pictures and refers to the fact to a movie camera. Not with 24 frames exposes
pictures but only 50%. This is due to a mechanical issue.
With TV (beta SP), wich
gives cameras various sensors with and without mechanical dazzles. The sensors
without are faster to move the field into the memory of the camera, However an
ugly effect with bright ranges are the problem of the faster technique "smear
Effect". They are preferred with fast sport photographs. The camera type (FT)
with mechanical screen carrier wich acts abit like a cam need a field time to
move it into the storage from the ccd. But it is only a field delay. For Pal it
is than 25fields exposure time for a second. With the fast sensors (IT) without
cover, without mechanics, need very less time (less than one microsecond).

So "blur length factor" in LW must be substantially smaller for this IT Sensor
(-around10%?) The FT Sensor has only 25 fields per second exposure time. The
Cinematic Cam has 12frames per second time to exposure. (base for LW 50% )

Does there is a mistake? How I can calculate the factor for 25f/s Pal?

christian

kenmac
05-13-2003, 08:53 AM
I use 10% for everything.

Draven
05-22-2003, 04:17 PM
Usually, film is around 50% blur length, but it actually depends on the shutter setting on the film camera. some cameras have fixed shutters at 180 degrees (50% blur length) while other cameras have adjustable shutters that can be anywhere from 180 degrees to usually about 72 degrees (about 20% blur length)

video cameras also vary in their mition blur by their shutter settings. Some video cameras have manually adjustable shutters, while others it is fully automatic.

If you're trying to get that film look, you should set the blur length for 50% and use dithered motion blur, with as many steps as possible. If you're shooting your own video footage, you should try to set the shutter on your camera to 1/60th of a second, which comes out to 50% blur length.

if you're working with footage from a client, you should find out what shutter settings they used.