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Beam Spread

Discussion in 'Lighting and Electrics' started by zac850, Mar 24, 2004.

  1. zac850

    zac850 Well-Known Member

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    I am working on my lighting plot now, and I was wondering which has the biggest beam spread, the ETC 50' or the S4-PAR? and also, what degree is the S4 PAR at? We're getting the compleate lense kit, so I'll be using the widest lense we have. Also, what is the degree that the S4-Par will shoot with the widest lense on it?

    thanks
    -zac
     
  2. digitaltec

    digitaltec Active Member

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    If you give me your throw distance, I can do the math for you.
     
  3. zac850

    zac850 Well-Known Member

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    Distance will just be 20 or 30 feet. I just need to know which gives a wider spread, so I know what lights to place where. I am going to give a rough sketch to the people who are doing the inertial load in, and I also want to start working on channel hook-ups and stuff....
     
  4. wolf825

    wolf825 Senior Team Emeritus Premium Member

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    In Photometrics, the beam spread & candela (brightness, footcandles) all depend not only on the instrument & lamp, but mostly the throw distance. If you can add that tidbit of info that would be a big help.....

    For example so you know it does make a difference---using a HP 575/115v lamp, the 50degree S4 is bright at about 350 footcandles with a beam-spread of a bit over 9' at a 10 foot throw distance, whereas the S4 Par, lamped the same using the narrow spot lense, at 10 foot throw distance gives you over 2000 foot candles and a beam spread of only 3' and some inches. Now If you used the WIDE lense at 10' throw distance you would have only 490 footcandles, and a 5'.3" x 9'.5" "wide-oval" beam spread. So you would have a brighter light with the S4Par, but more even coverage, although a bit dimmer, with the 50degree unit at a 10 foot throw on a wide flood lense...but with a narrow lense the Spar would kick the 50 degree's butt at 10 feet...provided you didn't care about size of the beam.

    Aint math fun... :)
    -w
     
  5. ship

    ship Senior Team Emeritus Premium Member

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    Digitaltec is right, but it's also completely different equipment where it comes to intent. A Leko will provide directional spot specific lighting, the Par while it will do some of that also provides flood lighting in doing so. Less focused than a Leko, more focused than a Fresnel. For theater, the PAR can is normally for specific applications or resorted to second choice fixtures after the good ones are used. Not similar beams. A S-4 PAR with wash lens has a 16x33 degree beam (out to 50% intensity) and 30x50 degree field angle (out to 10% which is the wash effect of it.) That's also before intensity of the beam or it's general effect is concerned no matter what distance which is also a factor. In a par it's normally hottest in the center and tapers in intensity towards the edges. In a Leko, it's normally balanced across the beam as with the Fresnel thus why they are in general less useful.

    Photometrics Handbook again or something you will find on the ETC website. The beams just plain look different much less feel different. I recommend you play with the lights before you finalize your design. Your Fresnels verses Lekos will be the base two groups of lighting with the Par fixture fitting somewhere between them as a barbaric wash of light on the subject. The flood lamp is much more harsh than the similar beam from a Fresnel, the spot is also much more harsh than that of a beam projector. Overall, such fixtures do serve certain purposes but are for the bulk of stage lighting, amongst second to choice fixtures for the standard look. Useful but not as much so in a general way to the primary lights.
     
  6. wolf825

    wolf825 Senior Team Emeritus Premium Member

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    According to Photometrics, the S4 50 degree using a 115v HP575 lamp will give you between 20 and 30 feet throw a size of 18'.6" - 27'.9" respectively, and a footcandles of 88 down to 33 respectively. Where the S4 par WIDE Flood will give you at 20-30 feet a beam spread of 10'6"x19' all the way to 16'x29' in size, and a footcandle of 54 to 78 respectively.

    hope that helps ya...
    -w
     
  7. zac850

    zac850 Well-Known Member

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    OK, so heres the basic question:
    At a 10 or so foot through (yes, i know, only 10 feet or so) which will have more beam spread, a 50' ETC S4, or one of the S4 Par's?

    its only 10 feet because this would go on the truss work on scaffolding suspended across the removable stage.....

    we're building a proscenium....
     
  8. wolf825

    wolf825 Senior Team Emeritus Premium Member

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    Hiya,
    From my first post--the numbers are correct in the example. At 10 feet from light to stage floor you get a 9' wide round beam of light with a 50degree, or a 9' x 5' "oval" beam with a S4 Par WIDE flood lense. IOW, at 10feet with a 50 degree S4, you have a big 9 foot in diameter circle of light on the floor...thats 9 feet in diameter. With the S4 Par you have a 9ft wide by 5 foot deep beam (depending on how you adjust the bottle for the beam width) which is NOT a round circle. IOW, its almost the same 9' coverage left to right but not upstage to downstage by comparison, provided the WIDE lense is going from SL to SR.

    SNIP:
    For example so you know it does make a difference---using a HP 575/115v lamp, the 50degree S4 is bright at about 350 footcandles with a beam-spread of a bit over 9' at a 10 foot throw distance, whereas the S4 Par, lamped the same using the narrow spot lense, at 10 foot throw distance gives you over 2000 foot candles and a beam spread of only 3' and some inches. Now If you used the WIDE lense at 10' throw distance you would have only 490 footcandles, and a 5'.3" x 9'.5" "wide-oval" beam spread. So you would have a brighter light with the S4Par, but more even coverage, although a bit dimmer, with the 50degree unit at a 10 foot throw on a wide flood lense...but with a narrow lense the Spar would kick the 50 degree's butt at 10 feet...provided you didn't care about size of the beam.

    -w
     
  9. digitaltec

    digitaltec Active Member

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    Given that Wolf answered your questons I guess I can put away my photometric handbook. :) Let me know if I can help you with anything else.
     
  10. ship

    ship Senior Team Emeritus Premium Member

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    hmm, any guesses on the next book to purchase?
     
  11. wolf825

    wolf825 Senior Team Emeritus Premium Member

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    Sorry if I beat ya to the punch--no harm meant...it was a slow nite and I had some time to kill since my photometrics book sits on my desk here. ;) But no worries--I will be away a lot the next several weeks with no real time to post much.. :)
    Given my photometric book is about 7 years old--I could always be wrong (or the book could have been wrong) and with all tech specs I welcome any corrections or updates that ETC may have done since my book was printed. I mean--Zac may have the HP750's for lamps, and not the HP575s..and that info is not in my book. :)


    cheers mate!
    -wolf
     
  12. digitaltec

    digitaltec Active Member

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    It's alright bud. I have a rough few months up ahead. Working a lot of freelance jobs plus school is going to limit even eliminate my time here on controlbooth.com for a while. Did work a cool gig last Saturday... President Bush’s Campaign Kickoff here in good old Orlando, Florida. I worked the load out. A very interesting experience if I do say so myself. :)
     
  13. zac850

    zac850 Well-Known Member

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    huh, thats a cool gig....


    anyway, that answers my question perfectly. I guess I didn't phrase what I was going for that clearly......

    anyway, thanks, I think i'm going to go with the S4-Par's above the stage, and save the 50's for some other parts of the stage.... im not sure where yet.....
     
  14. wolf825

    wolf825 Senior Team Emeritus Premium Member

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    Very cool...yah the election years are always busy ones. A friend did a Bush gig last nite locally...and in the past I've worked Bush Sr, Clinton and Reagan gigs so much I got to know some of the Secret Service guys and gals.. Those shows are always interesting..always fun and full of stories and challenges. Well I know my schedule will let me back on eventually--hope you aren't kept away from CB too long either.


    -wolf
     
  15. wolf825

    wolf825 Senior Team Emeritus Premium Member

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    Hiya Zac,

    FWIW, the 50's would make great down light, back light or high-side pipe ends depending on your stage size. I would also consider highly using them solely for gobo's--nice break ups on stage from the sides, or on a cyc/back wall would work most excellent and fill up a lot of space.
    Whats your base plot that you are trying to go for? If you post some of your needs for the plot to do and some of the points you have to hang from, folks on here may be able to help ya figure out what to do with all the toys.. ;)

    -wolf
     

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