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-   -   Shooting in frame mode (https://www.dvinfo.net/forum/techniques-independent-production/2111-shooting-frame-mode.html)

K. Forman May 22nd, 2002 06:45 AM

Shooting in frame mode
 
Everybody seems to like frame mode, and it sounds like a good idea for sharper frames. But when I have shot some footage, it looks jerky with ghostlike artifacts. Where am I going astray?
Thanks

Adam Lawrence May 22nd, 2002 09:57 AM

the only thing i can notice when shoot frame is the somewhat "jitter" when the camera pans too fast,,this is the only fualt I have noticed.

Ken Tanaka May 22nd, 2002 10:15 AM

Yes, quick camera movements will produce a strobing effect in frame mode, as will slow shutter speeds.

Don Donatello May 22nd, 2002 11:13 AM

frame mode is LESS sharp then interlace ( approx 20%) .. true progressive has more resolution then interlace video

IMO 30fps frame mode has little less stobing then when you watch FILM at 24fps on the big screen ...

next time you are at the movies notice the jitter when camera pans at 24fps ... the same distance panned at 30fps will be less jittery ...

strange that nobody complains about the jerkyness of FILM at 24fps on the big screen ??

Aaron Koolen May 22nd, 2002 02:58 PM

I do! :) To be honest I've only really started noticing it in the last year or so. Maybe it's the type of movies I've been seeing, I dunno. But now I see those long pans and the thing is jerky as hell ;) One thing though, when the camera does small, slower pans it doesn't seem that bad, but when I try and do something like that with an XL1s in frame mode, it still seems a lot jerky.Is there some sort of motion blur or something?

Don Donatello May 22nd, 2002 04:51 PM

i always shoot in frame mode at 1/60 sec ( unless i want FX of stutter) ...

on film projected at 24fps - they use a 3 bladed shutter that spins in front of the frame so the the 24fps is broken up into 72 flickers perhaps that gives illusion of it being smoother then it really is ????

Joe Redifer May 23rd, 2002 01:47 AM

Most working projectors today have a two bladed shutter. There are a few that have 3 bladed shutters, however.

Barry Goyette May 23rd, 2002 06:38 PM

As I understand it another difference between 24fps film and frame mode is that typically film cameras use a diagonal shutter, which is specifically designed to control the otherwise jerkey movements that might arise.

Interesting to me is that there is substantial difference in the frame mode of the gl1 and the xl1s relative to this issue. I find almost any horizontal camera (or subject) movement causes unacceptable strobing of the movement on the Gl1. The xl1s is barely objectionable even with the quickest movements. Initially I thought this was because of the 1/60 sec maximum shutter speed of the Gl1, feeling that at 1/30 on the xl1 was introducing a small amount of blur that softened the jumpiness. But I've done some comparisons on the xl1s, and to my eyes it is actually smoother at 1/60 than at 1/30. I have no idea why.

ErikFilmcrew May 29th, 2002 08:40 AM

An importent point!


Many find frame mode strobing when recording (as the look in to the LCD-eyepiece).

Keep in mind that all LCD screens (I know of) updates the picture slower and blurs in motion. Thats why LCD monitors are bad for computer games.

So if anyone thinks that frame mode is strobing and hasn't watched it in post on an ordinary monitor. I suggest that they do that first.

Then also, if the frame mode is used for film look, the brightness is recommended to be decreased and contrast increased. These two factors are also smothing out the strobe.


Have in mind that I use XL1 Pal and can not speak for Ntsc.


Regards,


Erik T

Don Donatello May 29th, 2002 11:38 AM

"typically film cameras use a diagonal shutter, which is specifically designed to control the otherwise jerkey movements that might arise"

i do remember back in college .. i was doing a project will alot of panning and the arri was coming out with too much strobe effect .. doing research i found that there are vertical shutters ( from top to bottom of film gate -frame) and horizontal shutters (from right to left across gate -frame) ..

the arri S and bolex had vertical shutters ... the eclair NPR had a horizontal shutter and the pans looked much smoother .. however tilt up/down were much smoother using the arri S with vertical shutter ..

Barry Goyette May 29th, 2002 11:56 AM

diagonal shutters
 
I have no experience with film cameras, my comment came from an American Cinematographer article on HBO's Band of Brothers, where they talked about switching the diagonal shutter out for a vertical (horizontal?)shutter in the battle scenes to give them a stuttery, choppy look. This effect was also used in Saving Private Ryan, for whatever its worth.


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