Theories on casues for image flicker

[Alex]

My tailslate method involves pointing one camera at the other cameras Time-code display...I get instant offset notation by using this method...the last shoot I did was the first time I was able to do BOTH a front and back Time-Code slate...that's how I know I was exactly in sync 80-90 minutes later.

Other times I have post-striped video with duplicate time-code from the other camera, perhaps the time-code generator "burps" every now and then, creating a very slow shift over the course of a one hour time-code dub, we're only talking a couple of frames...

I may have mistakenly assumed it happened at the time of shooting rather than when striping the tape with time-code.

I've heard that HI-8 will drift compared to S-VHS over the course of time.

Anyway, it sounds like Scottness did everything right!

Colder temperatures can definitely "freeze up" lubricants".

Perhaps the tech's at the Beaulieu Repair Station did not do a "thorough" overhaul.

I mean, actually taking apart the gears and relubing every gear and element.

Years ago, I saw a tech at Super-8 Sound COMPLETELY take apart a Beaulieu camera and re-do it from the ground up...

He said anything less than that and usually the cameras come back a lot sooner.




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Alex

[Nigel]

Roger--

While you are right most of what you say is based on Decks which hace AC power coming into them. I have had low betteries on my AatonCode Generator for my camera throw code. As long as the camera is keeping time I can't remove the battery but when the it gets to a certain point it starts to get dodgey to say the least. The best thing to do is make sure that the batteries are fresh and full and swicth them between every other roll--Discharge and recharge the batts that came off while the one that is on is full. I try to never get down to the "red" on any battery. I think it is a problem waiting to happen.

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[MovieStuff]

<BLOCKQUOTE><font size="1" face="Courier, Arial">quote:</font><HR>Originally posted by Alex:

Other times I have post-striped video with duplicate time-code from the other camera, perhaps the time-code generator "burps" every now and then, creating a very slow shift over the course of a one hour time-code dub, we're only talking a couple of frames...I may have mistakenly assumed it happened at the time of shooting rather than when striping the tape with time-code.
<HR></BLOCKQUOTE>

This still makes no sense to me. Did you notice any frames missing or doubled? Did you notice any timecode numbers missing or doubled? It is impossible for video to "burp" and skip or double any frames when laying down a recording without you seeing a glitch or some effect on the screen, even if you dupe through a TBC. Likewise, if your timecode is working correctly, it won't skip or double any numbers either. If it did, then timecode would be worthless for making frame accurate edits or window burn dubs for creating EDLs. If you've got drift, then there's something weird going on with your equipment since the whole purpose of timecode is to account for every frame with a discrete number.

Roger

[Alex]

The potential "burping" I speak of was not in video frames, but in the "striping" of the second tape with time-code from the first tape.

Analog time-code striping is virtually impossible to analyze because at very low speed shuttling, the numbers move in increments of one and would not reveal a "burp".

...when you play the tape at faster than a slow shuttle speed, it's impossible to see if there has been a dropped time-code frame due to the speed the time-code moves at.



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Alex

[MovieStuff]

<BLOCKQUOTE><font size="1" face="Courier, Arial">quote:</font><HR>Originally posted by Nigel:

While you are right most of what you say is based on Decks which have AC power coming into them.
<HR></BLOCKQUOTE>

All video equipment runs off of 12 volts DC, period. Even decks that have AC going into them use rectifiers to change the 120 VAC to 12 VDC. Therefore, the synch issue has nothing to do with AC current. The oscillators inside the units have no idea where they get their 12 volts DC from and continue doing their job whether they were installed in an edit deck to be used indoors or in a camcorder to be used out in the field. Video decks haven't used AC for synching purposes since the days of pre-color black and white video.

Making a distinction about AC operated video decks is like saying digital clocks that run on AC are more accurate than digital watches that run on batteries. In both instances, they use a crystal to keep correct time. More to the point, mechanical clocks that use line current for synch will drift over time quite a bit compared to crystal controlled time pieces, which are more accurate.

Roger

[Nigel]

I brought up the AC issue because it is a constant power source whether or not it is converted to DC. It will not run out or get low. Which is a major problem for TC Generators or motion picture cameras--Low Power.

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