shutter angle imagery

[Guest rajavel]

hi

can someone explain the various imagery that can be brought about using /varying the shutter angle and various fps.and whatever possible. can u give me examples from films of what was done to it to get whatever effet.

for example: how was the dance sequence in the 'moulin rouge' where the dancers skirts go in slomo and has a blurring quality to it.

thanks

raj

[David Mullen ASC]

hi

can someone explain the various imagery that can be brought about using /varying the shutter angle and various fps.and whatever possible. can u give me examples from films of what was done to it to get whatever effet.

for example: how was the dance sequence in the 'moulin rouge' where the dancers skirts go in slomo and has a blurring quality to it.

thanks

raj

<{POST_SNAPBACK}>

 

That comes from step-printing, i.e. slowing something down in post that was shot at normal speed or at a lower frame rate. For example, if you shot at 8 frames per second and triple-printed back to 24 fps, then motion would be normal speed but the motion would be blurry and "steppy". Has to do with using too few motion samples at longer shutter speeds (because of the low frame rate) being converted back to normal speed by repeating frames.

 

You know the basics:

 

Increasing the frame rate above the playback speed gives you more motion samples than normal, creating a smooth slow-motion effect when played back at normal speed.

 

Shooting at normal speed but repeating frames and then playing those back at normal speed gives you a slow motion effect that is "steppy" not smooth.

 

Shooting at a low frame rate and playing back at normal speed looks sped-up.

 

Shooting at a low frame rate and repeating frames to play back at normal speed looks normal in motion but "steppy" and streaky because the shutter speeds are longer at lower frame rates.

 

Shorter than normal (180) shutter angles creates less motion blur, causing motion to look choppy, stacatto, jerky. 45 degrees is a stronger effect than 90 degrees.

[Guest rajavel]

thanks a lot David for the valuable inputs. but wat do u think they have done for that wild dance sequence just before the introduction of Nicole kidman. how have thye achieved that mood. it is so blurry and slomo and sped up. thanks.

raj

[David Mullen ASC]

thanks a lot David for the valuable inputs. but wat do u think they have done for that wild dance sequence just before the introduction of Nicole kidman. how have thye achieved that mood. it is so blurry and slomo and sped up. thanks.

raj

<{POST_SNAPBACK}>

 

It would be hard to think of what technique they DIDN'T do in that sequence. But the streaky, swishy, steppy look is step-printing footage shot at a lower frame rate. But there's a lot going on in that sequence, even speed changes, in camera and in post.

[MiguelDelValle]

I have found that even 45 deg on the shutter will not make the staccato feel too strong unless the camera moves quick over the scene.

 

A few days ago I was shooting in an amusment park were we were shooting a kid on an atraction were a circular "car" moves in circles over the same axe and the whole thing (all the cars) move in circles. (I hope I explain myself).

 

I had two kinds of shot: in the same "car" with a kid were I had a medium shot (i dont remember if it was a 50mm or 35mm) were the camera stays with the kid and the background moves

 

The other shot was done froma different car that the kid was (blocked the movement of the camera car to see the kid moving in circles but at the same time all the background moving)

 

I was searching for a blurry background and shot a few versions:

 

45 deg shutter at 24 fps and

12 fps and 180 deg shutter and

a "non shuttered" shot.

 

the best image or the most blurried background was de 24 fps with 45 deg shutter version on the first 2 versions but the "non shuttered" version was great.

 

The "non shuttered" shot was made on an arri 435 camera pushing mode and set 6 times on the menu. The display gives you the temperature of the camera but desactivates the shuter so when you run the camera the shutter goes crazy without any control. When you stop the camera everything returns to normal.

 

The effect is quite interesting, the background is blurred with streaks of light from the highlights on the background, it was the shot who made it in to the final cut.

 

I guess would work very good for the typical war-fighting kind of shot or maybe a singer with a moving lit background.

 

I will put the quick time on my website pretty soon so you can see it.

 

 

cheers

Edited June 6, 2005 by MiguelDelValle