Variable speed projector question

[imissedthesixties]

So tell me...

How good will a variable speed projector be when trying to sync up sound to it? I understand that it will reduce flicker issues, and that it can (if you d a good job) come out very professional looking, but if you use a Chinon, or one of those with a variable speed knob, and not just an 18-24 selector switch, isn't it going to drift speeds during playback? I mean, here's my dilemma:

I'm going to be shooting audio on either a mini-disc or a DAT recorder (haven't decided yet). Regardless, my camera shoots at 18fps (i'm pretty sure). If I record my audio, try to sync up short takes top my film running at 18fps, wont it screw it up when I bounce it to 24? If you record the audio in parallel with the film running at 18fps, than how will that keep AT ALL when changed to 24fps to reduce the flicker??

~M

[MovieStuff]

First off, if you set your camera to 18fps, there is very little guarantee that it is REALLY shooting at 18fps. I've repaird enough cameras in my life to tell that they are all over the map, speed wise. Later sound cameras that were micro-processor controlled were pretty accurate when set to 18 or 24fps but silent models were a crap shoot.

Second, when you use a standard, three bladed variable speed projector to eliminate flicker for transferring to NTSC, you will end up at about 20fps and not 24fps. So even IF your camera were shooting at crystal synched, absolutely perfect 18fps, your video version of it will be at 20fps (actually 17.982). So you'd have to speed up your audio about .1% or it will fall behind the picture.

Third, it will drift, there's no doubt about it. Variable speed projectors are worse about drift than non-variable speed projectors, generally, because variable speed projectors use DC motors and not AC motors.

Hope this helps!

Roger

[MovieStuff]

<BLOCKQUOTE><font size=2 face="Verdana, Helvetica, sans-serif">quote:</font><table border="0" width="90%" bgcolor="#333333" cellspacing="1" cellpadding="0"><tr><td width="100%"><table border="0" width="100%" cellspacing="0" cellpadding="2" bgcolor="#FF9900"><tr><td width="100%" bgcolor="#DDDDDD"><font size=2 face="Verdana, Helvetica, sans-serif">Originally posted by imissedthesixties:
Is it possible though to change the shutter speed on a new miniDV camera to match the flicker rate of the three-bladed projector? </font></td></tr></table></td></tr></table></BLOCKQUOTE>

Not really. The shutter speed needs to be at a 60th of a second, normally. Also, the number of shutter blades is determined by the desired frame rate. A projector with 4 shutter blades will synch at 15fps (actually 14.985). That's because, regardless of the shutter speed, there are always 60 fields each second and the number of "flashes" produced by the shutter bladed must divide evenly or you get flicker. A four bladed shutter will flash four times for each frame of film. Four divides into 60 fifteen times, hence the 15fps frame rate. A three bladed shutter will divide into the 60 fields 20 times, hence the 20fps rate.

At 18fps, about the only thing you can do is change to 1/30th second but that results in a lot of ghosting on video frames. Yuck. Might as well use a Glaucoma TC-20 and be done with it.

Roger

[imissedthesixties]

Roger,

Is it possible though to change the shutter speed on a new miniDV camera to match the flicker rate of the three-bladed projector? I'm quite comfortable with the projector I have currently (has a nice bright picture) and i will be getting a new DV camera in a month, so if i DON'T have to use a vari-speed projector, i won't.

when I do a professional project, i'm gonna score a new camera anyway and probably have it crystal synched and get my transfers done via rank. Anyway, if you have any info on the miniDV cameras shooting at the non-vari speed projectors with changeable shutter speeds, that would be a big help.

~M