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Differences in focusing techniques.

Discussion in 'Lighting and Electrics' started by gabe, Jun 29, 2006.

  1. gabe

    gabe Member

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    Hi, today I started working at a new theatre program, I know the TD from last year but I haven't worked with him until now. We were doing a demonstration for a few actors and were refocusing a few lights. Now, at school whenever I have to pan a light I use the panning nut (read: f**k nut), when this guy adjusted a light he went straight for the pivot nut at the bottom of the C-clamp. I asked him about why he did it this way and he said that he used the panning nut just to set the height and then didn't touch it. Is this how most of you all focus your lights? Or do you do it differently?

    thanks,
     
  2. Teck

    Teck Member

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    We usually use the bolt at the bottom of the clamp instead of the panning bolt because our panning bolts tend to break or bend pretty bad.
     
  3. moojoe

    moojoe Active Member

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    i never use the F**k nut. its way to inacurate. whenever ive tried to focus using that, the light just shakes so much its imposible to do much.
     
  4. DarSax

    DarSax Active Member

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    I usually use the panning bolt, but not always. I have one of those mini-clamp wrenches (I forget the name, it's not a litespeed, it's one of the really small ones), and they have a place to adjust the panning bolt. I've never broken any that way (plenty at my theater have been sheared off), but if the bolt is rusted, then I have to either break out the ol' adjustable (which I keep with me anyways), or go for the bottom. So if I can I'll use the panning bolt, but oftentimes I'll have to use the bottom one instead.
     
  5. Goon

    Goon Member

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    I've been focusing lights for over 33 years. I can focus my entire rig of 400 conventionals in 60 to 90 minutes, tops, -that's with one person in a bucket and one person on the remote. Clients are amazed because other venues they go to will take all day to focus.

    Tighten that little side bolt so it will NEVER move. On the bolt at the bottom of the c-clamp, make sure the washer is below the yoke (never use rusted washers). Tighten the bolt just enough so the yoke will swivel with two-handed pressure but the bolt doesn't move. You won't even need a wrench to do your focus. Maintaining lights to work like this really pays off in time and aggravation.

    For the tilt, on units (like Altmans) that have a tightening knob on both sides, leave the left side just loose enough to move and tighten down only with the right.

    Do these things and you're reward will be the fastest and easiest focus.
     
  6. Footer

    Footer Senior Team Senior Team Premium Member

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    In theory you should never loosen the bolt on the clamp, though it is a pain in the arse to use the "pan" nut to pan the fixture. I usually end up grabbing the fixtures yoke and pulling on it till it moves then make sure I lock it down very well.
     
  7. moojoe

    moojoe Active Member

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    bragging a bit?

    but always pending on the situation. yea, if im doing a gig that will last only a day or so, and wont have much outside forces, ill do something like that.
    but if im outside or doing a perm to semi-perm install, you always tighten down as much as possible. would you want to have to go up and refocus every few months or if a strong gust of wind came through?

    oh, and Darsax, are you talking about the mega-combo wrench? its like 3 inches or smaller...
    i like those, and i have one on my keys, but for most work, its recomended that you use a c-wrench or a lightspeed or something, since those are average of 8inch handles, you can get a fair amount of torque, whereas a 2 or 3 inch wrench, you wont have much torque at all.
     
  8. BillESC

    BillESC Well-Known Member Premium Member

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    We refit all of our instruments with Cup Washers. This allows you to move the yoke of the fixture without having to loosen the bolt and stays where you leave it due to the constant pressure.
     
  9. DarSax

    DarSax Active Member

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    Yup, that's what I have. And I always have an adjustable if I need it, but honestly, besides rust issues, I've never had any sort of problem with my megao-combo, from torque or whatnot.
     
  10. lightbyfire

    lightbyfire Member

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    I used to use the yoke bolt on our aging and rusting fixtures, but with the new equipment i try to use the adjustment bolt whenever possible. (although just grabbing the yoke and twisting is awefully tempting most times.)
     
  11. Radman

    Radman Well-Known Member

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    I do it exactly the way Goon described. I rarely will use the pan nut.
     
  12. kingfisher1

    kingfisher1 Active Member

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    I'm just always in the habit of reacihng to the bottom of the clamp simply because its easy to access, anbd that how i was taught.

    "Tighten that little side bolt so it will NEVER move. On the bolt at the bottom of the c-clamp, make sure the washer is below the yoke (never use rusted washers). Tighten the bolt just enough so the yoke will swivel with two-handed pressure but the bolt doesn't move. You won't even need a wrench to do your focus. Maintaining lights to work like this really pays off in time and aggravation."

    I'm impressed that you confidently focus w/o out a wrench. correct me if i'm wrong but you either leave your fixtures loose enough to be knocked around or you never pan more the about 70 degrees in either direction. i generally leave teh pan nut loose enough to jerk the fixture around, because as you said it really saves time, but what happens when you spin teh fixture 180, the pan nut just locks down, then you use you wrench to loosen it so you don't have to be igor the strong to move the light again.

    anyway, i'm aurguing such a minute point here its stupid. everyone has their own system thtat they should use, but i am genuinly impressed that you can focus w/o a wrench. wow.
     
  13. Goon

    Goon Member

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    <<<"correct me if i'm wrong but you either leave your fixtures loose enough to be knocked around or you never pan more then about 70 degrees in either direction.">>>

    If a fixture gets "knocked around", the problem is not the fixture but whatever is doing the knocking. Fixtures shouldn't get hit under any circumstances.

    There's a sweet spot where the bottom bolt is wrenched tight, but the fixture can still pan with firm two-handed pressure. New fixtures come with a lock washer on the clamp. Throw it out and replace it with a flat washer and tighten the bolt. When you pan it with two hands on the corners of the yoke, it will slip between the washer and the C-clamp stem. The bolt stays tight in the stem.
    Yes, occassionally, it loosens up and will need to be re-tightened. I'm not saying I go up in the lift without a wrench. But time means everything. More time for programming = better show (and more time for doughnut breaks). Not only that, I'm on salary, not hourly.

    That pesky little side bolt has no washer so when the clamp stem is tightened to move with the yoke, it just loosens more.
    Doing it the Goon way, you'll only need to lock down the tilt with one bare hand. Trust in Goon!

    I always tie cables to the batten but never tie the cable coming from the fixture and always leave enough slack in that cable to be able to spin the fixture 360 degrees. The safety cable is what prevents you from spinning more than 360.

    My electrics are hung on double battens with power cables tied above which drop every 18 inches. Lower battens have marks every foot for quick positioning during a rehang.
     
    Last edited: Jul 3, 2006
  14. kingfisher1

    kingfisher1 Active Member

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    i not really expressing my self clearly here, but i think we are both arguing for the exact same method because i agree 100% with you
     
  15. ship

    ship Senior Team Emeritus Premium Member

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    Let's see... 1982... but really lighting say in 1984... darn, I loose...

    Fiber washer between yoke and clamp where I work does the two hand adjust type of focus needs sufficiently. As for lock washer throwing out or cone washer (expensive), to each his or her own. Somewhere over 1,000 fiber washers per year all custom stamped to USS 1/2" washer specifications and they work sufficiently to ensure that no matter how much you tighten the 1/2" bolt securing the clamp to yoke, you with two hands will still be able to adjust the fixture without un-loosening either the lock washer or regular washer which would tend to loosen or tighten. Wrong placement of one's intent to provide a swivel point in my reading. This especially in ensuring that those focusing still also re-tightien the main fixture locational bolt or don't over tighten it.

    By way of spring lock washer dirctly onto aluminum or even steel yoke, one can do better I agree and rarely do so. On the other hand the lack of lock washer of any type by way of hex nut head of screw offers limited to no locking in place ability. Best would be a internal or external tooth lock washer between that of the hex head and yoke in dispersing the pressure on the yoke. Otherwise, normally when doing a yoke to C-Clamp, I would do a washer against the yoke and spring lock washer against the head of the bolt.

    Believe it's the "Jesus Wrench" or "Jesus Nut" we are discussing and a search into those key words of the past would lend further info onto the subject.

    For record, when possible, I always first choose this 5/16-18x3/4" square head set screw as a primary adjustment part to focus with. When it slips by way of some gorilla's in the past having over tightened it - so it don't move, I grumble at them especially when I need to have to remove it so as to make the clamp into a studio/spud mounted clamp. You replace such damaged things.

    No excuse for a rusted bolt of any type, nor one that's stuck or slips. On the stage and under a controlled - this is the only use of it type of thing, this should never happen either over tightened and than grooved for locking T-fittings or broken Jesus nuts. What's wrong with adding a bit of oil to the bolt during the yearly maintinence anyway?

    My most favorite C-Clamp is one where someone installed a yoke knob in place of the set screw. While the bolt on the knob is most likely to be a lesser grade of steel, this knob in place of a cup point alloy grade set screw is by far the easiest solution for the problem of focusing the light. No stuck nut or need for a tool to adjust it. Expensive solution but the hand knob is possibly the better solution for this focus in doing it properly type of way.

    Yea, by way of past gorillas too lazy to adjust by way of the Jesus screw and especially in the cases of a slighly loose one, the inner T-shaped part it screws against gets channeled and won't lock very well at an assigned position. Once the gorilla of the past is done with this, do you work around this past person or replace the damaged part? There is a reason this part is there, don't know it other than it's a better thing to have than clamps without it.

    Beyond this a fiber washer or teflon washer between clamp and yoke is often easier to adjust with, but that's getting into more expensive add on parts to supplement those who would intent to just focus on the quick. Doing so properly is still the right method where possible.
     
  16. usesafesets

    usesafesets Member

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    From a touring standpoint I do not use the pad or set screw ether. Most of our conventional are in meat racks hung on Unistrut, or they are in pre-rigged truss. I do not care how the local hands focus, just as long as they are fast and do what the SM says.
     

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