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Help Mixing Tungston Bulbs with incadencent

Discussion in 'Lighting and Electrics' started by ricc0luke, Jun 25, 2004.

  1. ricc0luke

    ricc0luke Active Member

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    At our theater all of the lights except the borders above the stage are tunston-halogan bulbs. The borders are incadencent. The problem we are having is that the borders are coming up faster than the rest.... so when we bring up the lights first the stage goes blue and white... and then others come up less than a second later.... but still long enough to make it look bad. Whats the easiest way to deal with this? We are using Strand dimmers and a Strand 200 series board.
     
  2. bdesmond

    bdesmond Active Member

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    Your Stradn dimmers can be confiured with profiles to match the type of fxiture on the other end. Get the manual out, figure out the dimmer #s for the cyc lights, and set teh profiles for those dimmers to incandescent.

    This should take care of the problem.
     
  3. Les

    Les Well-Known Member

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    The source of your problem is that it takes alot less power to light your borders than it does the rest of your lights. So, when you bring up a dimmer, the incandescents light more readily to a lower amount of power than do the TH. I would try changing the profiles as per the previous suggestion, but I do think that is the exact problem.
     
  4. ricc0luke

    ricc0luke Active Member

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    Ok... I have checked the manual front and back to find anything even close to changing the profiles for different lamps. The closest thing I found was how to get the CD80 Digital Pack Controller (Modified Square Law Curve) to match the CD80 Mulitplexed Analog and Discreet Analog Controllers (Analog Pack Matching Curve).

    I believe we currently us the Modified Square Law Curve with our dimmers... But I have no clue if this is what you are reffering too. We use Strand CD80...

    Other than the stuff above I could find nothing along the lines of what you are talking about in the manual.

    Any ideas?
     
  5. zac850

    zac850 Well-Known Member

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    I believe he is talking about the same thing as the "modified squared law curve". If you change that to something else, it may work. Another way, more difficult, would be to program it as an effect. Set it so dimmer X comes up and then however much longer, dimmer Y comes up.

    This isn't as easy, but it should work.
     
  6. ricc0luke

    ricc0luke Active Member

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    Programing it as an effects would be a pain-in-the-ass way of doing it on and ETC board.... yet alone a Strand....

    that is pretty much out of the question!

    as far as switching it to something else other than modified square law...
    i think you have to switch the entire rack... not just one dimmer... if anyone out there is familar with Strand's CD 80 dimmers and knows for sure... their help wpuld be appreatied!
     
  7. ship

    ship Senior Team Emeritus Premium Member

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    So programming a light board is a pain in the rear ha? Try running the same effect on a two scene preset with the normal scene on the X/Y fader and the cyc dimmers in indipendant mode so you can control their rate seperately and thus match the fade up rate.

    In other words, programming if not easy enough becomes an opportunity to figure out how to make it become easy.

    I expect that in writing a cue on most boards today you can increase or decrease the fade up rate of specific dimmers within a cue, we are not talking about a early 90's light board where fade up rate and group masters on a memory was still new here after all.

    Given this is still not a possibility to control specific dimmers on a different rate, what about assiging two cues to the scene by way of link so that the ones that fade up slower get a sooner start yet the other lights in their own time cross fade to follow and match the pace to the end of the fade. Just a timing issue of no doubt a second or two given the new maximum rate of up-fade is now in matching the larger/high wattage filaments.

    Otherwise two cues involving all lights and linked to "go" when the first cue reaches completion. Say Lekos to 40% on cue one, than Lekos to FF along with Cyc to FF in piling on them to your cue thus by timing of actual up-fade time and percentages necessary you still achieve the same end result. Chances are you are going to be getting a slight glow anyway off the Lekos and it won't make much notice when being cross faded against the last cue.

    Still it would be just easier to slow down the dimmers that control the smaller filament lamps. Switching to analog/linear verses ... or was that analog verses linear dimmer curve for the specific dimmers might be an option as advised and it might be possible for the CD-80 to do this, or might be possible to control this at the soft patch of the board. Don't know, I do remember that at an old theater there was both types of dimmer available thus one was specifically for the cyc lights - but it's been a lot of years.

    Hope it's of use in some way = my musings on it at least to me seeming easy enough to program.


    By the way, this might also be an issue of trim settings. You can boost the trim of your dimmers on the Lekos so their lamp warming current is a bit higher as long as you turn it back down after the show. This is done normally with a TRUE RMS voltage meter and a 1Kw PAR fixture for load and also to look at what you are doing in trimming it. CD-80 packs are easy to trim. Adjust the lights to the point that when dark there is just a bit of glow to the lamps as opposed to them being for the most part dark but still having the 7 to about 15v warming current. At this point, no doubt about 20v, you will hopefully have sufficient jump start to your Lekos so they can come up to the same level at the same speed as the cyc lights. Such cyc light dimmers might also be trimmed down to their lowest setting which will still let them achieve say 95% of the maximum voltage and thus also take a little longer to heat up - but only slightly.
     
  8. bdesmond

    bdesmond Active Member

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    The CD80 manual discusses setting a dimmer for an incandescent curve on page 77. Do you not have this?
     
  9. ship

    ship Senior Team Emeritus Premium Member

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    he he he, I guess it is kind of pre-1979 technology thus given that's my rational for what I know how to use best verses what others know, I should know but I don't know - get it? I'm checking my disk of manuals: .... nope, nothing for Strand. (Don't bother sending it to me either, I don't plan on ever neeing to read it.)


    It has been about three years since I touched my last CD-80, and that was in testing trimming some we got from a local TV station for resale to someone else. At best all that is left over are a few 6Kw per channel versisons of them that were left out in the rain if not sent to the dumpster.

    At least four years since I did anything mechanical after that to them such as change out Din to what ever control or power source types and outputs. Such dimmers are long gone where I work and now too electronic for me to have to touch. I never used the CD-80 on shows, I just prepped them as individual packs for resale thus never read the manual much less knew of such an option. That is a nice option to have however.

    I guess you have me on CD-80 knowledge, do you have them where you are?
     
  10. bdesmond

    bdesmond Active Member

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    Yeah. Like 120 of them or some such number. About 2.5 racks worth

    My reply was actually more directed at the original author as he said he couldn't find it in his directions.
     
  11. ricc0luke

    ricc0luke Active Member

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    I am not sure if I have the actual full user manual... because it has all been copied.... so I will have to check because at the theatre because I have sinced returned it. Thanks for all the info and help, even if we can't figure it out... I have learned alot about dimmers for all of this. Thanks Again!
     
  12. ricc0luke

    ricc0luke Active Member

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    I have done some research into the manuals online at Strands site...
    You have a CD-80sv Dimmer...
    We have a CD-80 Pack Dimmer...


    The CD-80sv is a permenant dimmer rack is it not? For some odd reason when they re-did the lights at our theatre bought portable dimmer packs. Here's the kicker... the dimmer are located in the set shop where there is sawdust galore! So we ended up building a cabinet with a ton of filtered vents to house the dimmers right after they put them in.... that was over a year ago and so far its fine.... but I'm not holding my breath!
     
  13. bdesmond

    bdesmond Active Member

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    You are correct. I have racks of SV series dimmers. It didn't really dawn on me that you might have packs.
     

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