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trimming for headroom and dynamic balance


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#1 robert weldoff

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Posted 14 July 2010 - 08:50 AM

hi all

was wondering how/if/when you trim for headroom how does this affect your dynamic balance? would you have to set up and rebalance or would the small adjustments you make not have a major effect on the way the sled behaves?

i think but if wrong pls correct me, that trimming would put you out of dynamic balance and how do u fix this?

regards
rob
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#2 RonBaldwin

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Posted 14 July 2010 - 01:15 PM

Cue Tiffen rep
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#3 Jens Piotrowski SOC

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Posted 14 July 2010 - 03:17 PM

Cue Tiffen rep



headroom is overrated....... :D
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#4 Mark Schlicher

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Posted 14 July 2010 - 09:15 PM

Robert,

If you trim for headroom it throws the rig out of dynamic balance. So it's a tradeoff that you make, depending on the needs of the individual shot. You compensate for the lack of DB with your operating technique.

The only way to have dynamic balance and trimmed headroom simultaneously is to have a tilting topstage. Among high-end sleds, only Tiffen offers that feature, which is protected by a patent.

Some swear by the tilting topstage, and some vigorously state the opinion that it is an unnecessary luxury. Much fine work is produced everyday with non-tilting stages. Many famous shots were made with rigs that couldn't be dynamically balanced. So excellent technique can overcome the characteristics/limitations of a sled.

Do a search and you will find a recent lively debate on this very subject.


hi all

was wondering how/if/when you trim for headroom how does this affect your dynamic balance? would you have to set up and rebalance or would the small adjustments you make not have a major effect on the way the sled behaves?

i think but if wrong pls correct me, that trimming would put you out of dynamic balance and how do u fix this?

regards
rob


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#5 Eric Fletcher S.O.C.

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Posted 15 July 2010 - 12:42 AM

Well actually...

First things first lets clear up what Dynamic Balance REALLY is.

"Dynamic Balance" is a state in which the the rig when spun will spin level. Key word is Level.

You achieve that level spin by balancing the below the gimbal forces and the above gimbal forces.

It does't matter anyway since the moment you tilt for headroom you by definition are no longer Dynamically Balanced

The bottom line is get your rig in DB in the level state then forget about it. Headroom trimming is a fact of operating, deal with it.
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#6 Jerry Holway

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Posted 15 July 2010 - 08:33 AM

Robert- you asked how often you trim for headroom - I suggest you do it as often as you can - it makes for better operating.

Does it affect DB? Yes, as all have stated in these many threads. So, as Eric says, you deal with it.

I tweak headroom when necessary during a shot (oh, the joys of a motorized stage) and all the time just before a shot, and of course it affects DB.

The basic idea is to have the rig's inertia, balance, and its gimbal, arm, vest, FF, etc. - all the tools and techniques you have - help you get the shot. The more wisely you use them, the more help you get.

Setting headroom with a tilt head preserves dynamic balance (or helps to), which becomes more important the more or the faster you pan, and the more tilt that is required - but we all made wonderful shots for years without it, and we continue to do so.

Certain shots are extremely difficult without the tilt head (or a wedge): accurate pans with a lot of tilt in the lens, and they are a breeze to do with the tilt head... but that sort of shooting is rare. The argument can be made that the sort of shots we do with Steadicam that are commonplace now were rare way back when, because the technology did not exist... the same can be said for any technology.

BTW, I'm contemplating a lot of wonderful shots with Tango (impossible to do prior to its invention) - and DB is hellishly important for that tool.

Jerry
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#7 robert weldoff

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Posted 15 July 2010 - 05:09 PM

hi all

thanks all for the responses,
i like your wit Ron :)

i guess i just gonna deal with it until im good enough and have a bank balance to afford an ultra 2 :)

to jerry,
i just watched your dvd yesterday that you made, (peace be with Ted) very helpfull as i also have your book, and watching the vid after working through the book i feel im on the right path in terms of technique and hopefully no bad habitss.
i also appreciate the fact you as one of the "masters/inventors" haver the time to answer questions posted by stupid people like myself.

kindest and humbled
rob
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#8 Jerry Holway

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Posted 16 July 2010 - 03:17 PM

Rob-

anyone who is doing this seriously isn't stupid... (or alternatively, we all are dumb as posts...oops, I think that idiom has a new meaning now...)

good luck

Jerry
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