Jump to content


Photo

NPR Vertical Smearing, HELP! ASAP!


  • Please log in to reply
5 replies to this topic

#1 Justin Lovell

Justin Lovell
  • Basic Members
  • PipPipPipPip
  • 262 posts
  • Cinematographer
  • Toronto

Posted 07 January 2009 - 01:03 AM

Hope you can help me out!!

Just posted the clip online.
I had my Mirror replaced, and I don't know if this probem is with my mirror or with a problem of the way I setup my loops.

It looks like a streaking vertically, that becomes more noticable around highlights. It really shows up more when I have my shutter angle below 180 deg. (My tests show the angle at 180 and 70 degrees).

Could you check it out, I'm supposed to be shooting tomorrow morning (wed morning) at 8:30am! A little worried that the problem is with the mirror, and not with the loops.. if so, I gotta fix it asap.. somehow!

http://www.framedisc...Sequence 01.mp4

Thanks!!!!
  • 0

#2 David Mullen ASC

David Mullen ASC
  • Sustaining Members
  • 20068 posts
  • Cinematographer
  • Los Angeles

Posted 07 January 2009 - 01:23 AM

Looks to me like a shutter timing error.

The way to check this is to load a mag with some dummy film and draw a long squiggly line down the length of the roll using a Sharpie.

Put the mag on the camera, take the lens off, and look thru the open port at the film in the gate as you advance the film manually, slowly. If the shutter is working correctly, that squiggly line visible on the film in the gate should not move until the mirror shutter has closed over the gate completely. If the timing is off, then you'll see that line start to move (and squiggle side to side as the film advances, which is why you don't want to draw a straight line) just as the mirror shutter is starting to close over it.

This means that the last percentage of exposure will be happening as the film is advancing, so the brightest areas will streak upwards vertically in the shot.

I don't know if there is a quick fix that you can do yourself to the shutter -- probably a technician has to fix it.
  • 0

#3 Justin Lovell

Justin Lovell
  • Basic Members
  • PipPipPipPip
  • 262 posts
  • Cinematographer
  • Toronto

Posted 07 January 2009 - 01:49 AM

oh man.. thanks david. I will check that out right now!

Anyone have a NPR service manual?
  • 0

#4 Justin Lovell

Justin Lovell
  • Basic Members
  • PipPipPipPip
  • 262 posts
  • Cinematographer
  • Toronto

Posted 07 January 2009 - 02:10 AM

just as you suspected, the film is in motion before the mirror covers the film.
Shouldn't be a major adjustment to be made, but would prefer to do it with the service manual to reference!
  • 0

#5 Justin Lovell

Justin Lovell
  • Basic Members
  • PipPipPipPip
  • 262 posts
  • Cinematographer
  • Toronto

Posted 07 January 2009 - 02:05 AM

just as you suspected, the film is in motion before the mirror covers the film.
Shouldn't be a major adjustment to be made, but would prefer to do it with the service manual to reference!
  • 0

#6 Justin Lovell

Justin Lovell
  • Basic Members
  • PipPipPipPip
  • 262 posts
  • Cinematographer
  • Toronto

Posted 07 January 2009 - 02:57 AM

just as you suspected, the film is in motion before the mirror covers the film.
Shouldn't be a major adjustment to be made, but would prefer to do it with the service manual to reference!
  • 0


Tai Audio

Glidecam

Wooden Camera

CineLab

Metropolis Post

FJS International, LLC

Media Blackout - Custom Cables and AKS

Abel Cine

Ritter Battery

New Pro Video - New and Used Equipment

Willys Widgets

Technodolly

The Slider

Gamma Ray Digital Inc

Paralinx LLC

Visual Products

CineTape

Rig Wheels Passport

rebotnix Technologies

Aerial Filmworks

Broadcast Solutions Inc

New Pro Video - New and Used Equipment

Wooden Camera

Visual Products

Broadcast Solutions Inc

Rig Wheels Passport

CineLab

Media Blackout - Custom Cables and AKS

Abel Cine

FJS International, LLC

rebotnix Technologies

Ritter Battery

Paralinx LLC

Willys Widgets

CineTape

Aerial Filmworks

Glidecam

The Slider

Tai Audio

Metropolis Post

Technodolly

Gamma Ray Digital Inc