Author Topic: Help! Quick...shutter speeds  (Read 1316 times)

0 Members and 1 Guest are viewing this topic.

metroshane

  • The Ultimate Boon
  • ***
  • Posts: 458
  • Respect: +1
    • http://www.explosivofilms.com
Help! Quick...shutter speeds
« on: April 15, 2004, 01:48:42 PM »
0
We are shooting this week end with the JVC HD cam.  On the automatic setting, it shoots at 1/30 (which coming from the world of still photography tells me that if you shoot 1/30 of a second, there are 30 frames per second).  This setting has a problem with tracers...and you can change the shutter speed higher to 1/60 or 1/250, etc. , which is what I'd like to do.

My question is....how does this relate to frames per second in the video world.  Is the shutter speed really just a digital compensation tool...or does it really make the shutter move at 1/250th of a second.  If it's moving at 1/250th of a second...then how is it still shooting 30 frames a second?  I'm not sure I get what's going on electronically.

someone help please.
We live in an age that reads too much to be intelligent and thinks too much to be beautiful.

SoNowThen

  • The Master of Two Worlds
  • *****
  • Posts: 4536
  • Respect: +9
    • 24/30 Cinema
Help! Quick...shutter speeds
« Reply #1 on: April 15, 2004, 01:57:34 PM »
0
I'm pretty sure it's just an effect tool, since there is no shutter in a video camera (is there?). But the effects are similar: going lower than 1/30 will make it strobe, and going higher will give you that effect where you can capture fast motion (like the spinning blades of a fan) in detail. At least that's the way it works on my Canon XL1S.
Those who say that the totalitarian state of the Soviet Union was not "real" Marxism also cannot admit that one simple feature of Marxism makes totalitarianism necessary:  the rejection of civil society. Since civil society is the sphere of private activity, its abolition and replacement by political society means that nothing private remains. That is already the essence of totalitarianism; and the moralistic practice of the trendy Left, which regards everything as political and sometimes reveals its hostility to free speech, does nothing to contradict this implication.

When those who hated capital and consumption (and Jews) in the 20th century murdered some hundred million people, and the poster children for the struggle against international capitalism and America are now fanatical Islamic terrorists, this puts recent enthusiasts in an awkward position. Most of them are too dense and shameless to appreciate it, and far too many are taken in by the moralistic and paternalistic rhetoric of the Left.

metroshane

  • The Ultimate Boon
  • ***
  • Posts: 458
  • Respect: +1
    • http://www.explosivofilms.com
Help! Quick...shutter speeds
« Reply #2 on: April 15, 2004, 02:03:26 PM »
0
Thanks...that's what I thought.  I just didn't want to be wrong, shoot at 1/250th of a second...then have to do some crazy conversion to make it 30 frames (or 24) per second.
We live in an age that reads too much to be intelligent and thinks too much to be beautiful.

pete

  • The Master of Two Worlds
  • *****
  • Posts: 5510
  • freakin huge
  • Respect: +361
    • my site
Help! Quick...shutter speeds
« Reply #3 on: April 15, 2004, 02:10:29 PM »
0
no, film and video cameras do that through changing the shutter angle, not the speed, or something like that.
“Tragedy is a close-up; comedy, a long shot.”
- Buster Keaton

mutinyco

  • The Master of Two Worlds
  • *****
  • Posts: 1476
  • Respect: +2
    • http://www.crossoverfollowing.com
Help! Quick...shutter speeds
« Reply #4 on: April 15, 2004, 04:15:46 PM »
0
Interesting that it's normal speed is 1/30. Perhaps that because of the HD? The Panasonic GVX100A is set normally for 1/60 -- at 30 fps.
"I believe in this, and it's been tested by research: he who fucks nuns will later join the church."

-St. Joe

SoNowThen

  • The Master of Two Worlds
  • *****
  • Posts: 4536
  • Respect: +9
    • 24/30 Cinema
Help! Quick...shutter speeds
« Reply #5 on: April 15, 2004, 04:21:34 PM »
0
same with my camera
Those who say that the totalitarian state of the Soviet Union was not "real" Marxism also cannot admit that one simple feature of Marxism makes totalitarianism necessary:  the rejection of civil society. Since civil society is the sphere of private activity, its abolition and replacement by political society means that nothing private remains. That is already the essence of totalitarianism; and the moralistic practice of the trendy Left, which regards everything as political and sometimes reveals its hostility to free speech, does nothing to contradict this implication.

When those who hated capital and consumption (and Jews) in the 20th century murdered some hundred million people, and the poster children for the struggle against international capitalism and America are now fanatical Islamic terrorists, this puts recent enthusiasts in an awkward position. Most of them are too dense and shameless to appreciate it, and far too many are taken in by the moralistic and paternalistic rhetoric of the Left.

warmstepvision

  • The Call to Adventure
  • *
  • Posts: 23
  • Respect: 0
Help! Quick...shutter speeds
« Reply #6 on: April 16, 2004, 11:50:47 AM »
0
The standard dv cam(shutter angle 180) that shoots at 30fps (actually they are fields) has a standard exposure time of 1/60 . Easy way of finding the shutter speed of a standard 180 degree shutter is by dividing one by double the frame rate.  Standard shutter for 24fps would be 1/48 and so on. By standard i mean the speed that was adopted to sync sound in most natural way. But 1/30 shutter seems a bit odd for a standard hd cam meaning it is shooting your footage at 15 frames!? Can not be so, my theory is that your cam has a variable shutter speeds locked into the automatic setting? Well basically by modifying the shutter speed you produce the same effect as you would modifying frame rate so increasing the speed of the shutter to 1/250 means you are shooting at 125 frames causing the aperture to move up around 2 stops. Film exposure is a lot easier to learn than video. You never know what they stick in your good old hd cam.

 

DMCA & Copyright | Terms & Conditions | Privacy Policy