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Stage Lighting For Video Questions

Discussion in 'Lighting and Electrics' started by zackw250, Feb 7, 2005.

  1. zackw250

    zackw250 Active Member

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    Hello...

    Currently in our main theatre (1500 seats) we use ColorTran ellipsoidals for lighting our stage positions. We shoot video at every service for both IMAG (Image Magnification) and Broadcast.

    I am not happy with the spots because every time our pastor wants to get up and move around during his sermon (even if it's just a couple feet) he either goes into the dark, or there are lines where he transitions from one ellipsoidal to another. This is why I would like to use two fresnels at 45 degree angles to light the pastors area.

    Since we light for video everything has to be 3200K.

    Our stage is 60 ft wide by 26 feet deep. The area i want to light is about 20ft by 10ft (roughly). Any suggestions for what fresnels I should use. Throw distance from FOH electric to stage is about 20 feet. I would need barn doors to keep the light from spilling onto our CYC or the front of the precinium (sp?).

    Any suggestions on type, make, model, wattage, etc? And since were a church budget is always in the back of our minds. Any ideas or thoughts would help! Thanks.. ZW
     
  2. moojoe

    moojoe Active Member

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    instead of buying fresnels, why not just modify the ellipsoidals? if you want to get rid of that line when it crosses, just stick in some frost. Rosco 119 would probably do it. it would just difuse the border of the light so that you dont see the transition thats like $6 compaired to a few hundred.
     
  3. cutlunch

    cutlunch Active Member

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    Good idea Moojoe. Zwackw250 are there only one ellipsoids per area? If so pair them up the same way you were going to do the Fresnels. With the frost or diffuser inserted this will spread the light. For the size of area you are talking about I would divide the front of the pastors area into three areas. The area is almost to deep to be one area. I would have lights inside the proscenium arch to light the back of the area. If you are doing this it might be worth reviewing how you light the whole stage at the same time.
     
  4. TechWench

    TechWench Member

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    Im probably VERY wrong, but dont you want your color temperature at 5600k?

    please correct me if im wrong! I had a crash course in lighting for television. but maybe i am remembering wrong!

    :roll:
     
  5. zackw250

    zackw250 Active Member

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    Ok.. to clear some stuff up...

    Yes, each lighting area has two ellipsoidals @ 45 degree angles. The problem isn't when passing between those two ellipsoidals, its from when he passes into the next lighting area.

    We already diffuse the light, but the camera sees the transition between (either as a dark line or a bright line).

    Plus, another reason we want to use fresnels verses ellipsoidals is the number of fixtures. Currently we use 6 ellipsoidals to light the pastor's area. If we got fresnels, we would only need 2, maybe 3. I have already decided that fresnels are the best choice, I just need to know if anyone has suggestions for beam sizes, wattage, etc.?

    And you are wrong, correct color temperature for video is around 3200K. 5600K is more the tempature of our intellegent lights.

    Thanks...ZW
     
  6. cutlunch

    cutlunch Active Member

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    If your dimmers can handle it then at least 2kw to help counter the loss because of the distance from FOH electric. I would go to the manufacturers websites for the brands of lights you can get there in the States. Start with your favourite company. Most of them should have tables that show light output as factor of beam angle, beam diameter on stage,distance from object etc. for their Fresnels.

    For example the link below is to the spec sheet for a Colortran 2kw Fresnel which would appear to do your job. Before buying I would get my light meter out and measure the current levels in the pastor's area so you can compare that with spec sheets.

    I take it that you had spent a lot of time refocusing the ellipsoids before you decided on the Fresnel option.

    http://www.colortran.com/catalog/pdf/lthfres8.pdf
     
  7. TechWench

    TechWench Member

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    I was thinking Intels...my bad!

    :oops:
     
  8. zackw250

    zackw250 Active Member

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    cutlunch -

    Thanks, I dont currently have a light meter, and I doubt church finances would allow me to purchase anything over $150. Any suggestions for a light meter on the cheap?

    And yes, I have spent many a times up there focusing the ellipsoidals, and am frankly tired of it.

    Thanks...
     
  9. SuperCow

    SuperCow Active Member

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  10. cutlunch

    cutlunch Active Member

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    Hi. I did a quick search for a Lux meter on the web and found this site below. This meter would probably be all you need, it appears similar to the ones that sell in our equivalent of Radio Shack. You have some interesting companies in the states lol.

    http://www.familydefense.com/luxmeter.htm

    I can't remember the figure at the moment but I think you can have about a 20 lux light level difference before it becomes too big of a problem for the camera.

    If your camera picks up a good picture without the lights being at 100% this will help later as the lamps gets old, you will be able to use them longer before changing them.
     
  11. SuperCow

    SuperCow Active Member

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    That sounds more like a light sensor than a light meter on their site. Being a "home security" store, I doubt that they are selling an accurate light meter, but a light detector.
     
  12. ship

    ship Senior Team Emeritus Premium Member

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    Expecting that you are using 500w BTL lamps in your Fresnels, which have a normal color temperature of 2,950°K to 3,050°K, you might switch to a BTM instead which has a color temperature of 3,200°K.

    Difference being 100 to 150 hours in life instead of 500 hours in life. On the ohter hand, you will get 2,000 more Lumens in output.

    Than again, you could also color correct tthe BTN with some say 1/8 CTB color correction gel such as a Lee #218.
     
  13. Peter

    Peter Well-Known Member

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    I managed to find an old lighmeter (similar but simpler then one pictured) in my grandparents house as we were packing them up to move, my grandpa saw that i was interested and gave it to me. As far as I can tell it was one made exclusivly to set camera exposure lengths and the numbers on it dont seem to make much sense at all. I use it to reference the difference in brightness between different parts of my stage.

    My point is, maybe a bit of digging arround in some older houses might turn up something, especilly if the person living there used to be into photography before the day of wiz bang computer controled auto everythings.
     
  14. RonaldBeal

    RonaldBeal Active Member

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    Video

    TechWrench:
    There is no fixed color temp for video. The biggest issue is to make sure all of the lights match in color temp. Generally, Video shot outdoors is balanced to 5600K (sunlight) while video indoors is balanced to 3200K (approx range for most incandescent fixtures at full output.) Consumer cameras use the white balance function to set the cameras internal electronics to the appropriate color temp, while pro cameras have an internal filter wheel to dial in color temp (plus white balance.)

    ZW, the best solution to your problem is a follow spotlight (even an ellipsoidal on a stand is better than nothing.) As long as you don't overpower the background (2 to 3 times brighter at most) you will be able to keep a constant level. This is how practically ALL live presentational events for broadcast are lit (Including Grammys, Emmys, Oscars, Superbowl Half-time show, etc...) You can get some decent incandescent followspots for a fairly reasonable price (maybe some altman 1000Q's or 360Q's)

    Peter:
    I'm guessing your light meter is a photographic meter (maybe Gossen brand?)
    It is probably calibrated to F-stops (or maybe even T-Stops)
    There should be a scale dial on the meter to adjust based on film speed. 320ASA should be a close approximation for most video cameras.
    In bright sunlight your meter should peak out ( or at least hit F-22 to F-32-ish if it goes that high. For indoor events (without lots of windows to let sunlight in,) you will probably be in the F-4 range. This chart will let you convert f-stops to footcandles:
    http://www.geocities.com/thombell/charts.html
     
  15. Peter

    Peter Well-Known Member

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    Hey Ronald, thanks for that info! The meter is currently @ school, and I'll see if I remember to bring it home on monday and I'll take a look. I remember not beeing able to tell what the numbers were about b/c it was quite seriously gummed up. Even worse was the spinning calculator to convert the reading between different units, it now spins as one thick unit (instead of several layers) and is completely unreadable. If I wanted to put some serious time into it I might be able to pull it appart and let it soak in a gental solvant and see if came appart, but I dont really think I need the #s that bad. When it comes down to it, it's all realative in the theator anyways, the audience (and I) should be able to tell if scene is brighter or darker. Thanks for the info though, I'll certainly take a second look at it and see what I can find.
     
  16. zackw250

    zackw250 Active Member

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    Um.. no a followspotlight isn't the best option. Not in my situation. Have you ever worked in a church environment, if you have then you would know the top ten reasons why we wouldn't use a followspot.

    Thanks for your opinion however. ZW
     
  17. RonaldBeal

    RonaldBeal Active Member

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    Respectfully, yes I have worked in church environments, and seen more followspots than not from churches that broadcast. What it is so unusual about your situation that would prevent it?
    The biggest mistake is people assume that there will be this huge light, casting akward shadows etc. The best use of a FS for video applications is to be subtle. Often spots are dimmed down, thrown out of focus, diffused, ND, etc... just to keep the key even and distributed.
    Lets see... Reasons (excuses) to not use a FS:
    1. The beam "looks" different.
    You can get spots that basicly are source4's with a dimmer/iris kit, and boomerang that hangs off of the gel holder, so it will look the same
    2. Can't get someone to run it.
    That is as more a political reason than technical, but oh the difference one person can make.
    3. FS's to noisy.
    Only depends on the type of light.
    4. No where to put it.
    This depends largely on the layout of the building, do you have balconys? You can usually finagle a position there, especially if you show before and after footage.

    I can't think of many more reasons not to use a FS, and I can think of a whole lot more TO use them.

    Hope this helps and good luck
     
  18. zackw250

    zackw250 Active Member

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    1) It will look different since you will be able to see the beam from the balcony. Especially since we usually use a light haze during services. The beam will stand out like a sore thumb (I know this because we own a followspot and have used it in there before).

    2) Your right it is a political reason. However, in a church setting political & technical reasons become the same.

    3) No noise issues.

    4) We do have a followspot location. However the church does not want any seats to have obstructed views (this is why our cam positions are in the back with large glasses and zooms).

    I am not saying FS is a bad situation for churches in general. However, I KNOW FOR A FACT that a FS is not a usable solution in my church, I have already thought through this before posting my initlal quetsions about fresnels.

    But thanks for your thoughts.
     
  19. squigish

    squigish Member

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    It seems like you're having an issue with balancing the light output of different areas, specifically the spaces in between the areas. While I understand that you clearly want to go buy some more equipment, it sounds like you may be able to solve the problem with either re-focusing your existing equipment or adding diffusion. You also may be trying to cover too much space with too few insturments, in which case I would either buy more ellipsoidals or re-evaluate if the entire space needs to be lit.

    What kind of ellipsoidals are you using? I know that you said that they were colortran, but what beam spread? What lamps? How far are they throwing? How big are your areas onstage?

    Before you go out and buy more equipment, I would try and re-focus the equipment that you already have to see if you can get more even coverage. Keep in mind that your areas need to overlap a little bit in order to maintain an even coverage. The best example that I can think of of the problems created by too little overlap, especially with a sharp focus,is from several years ago during our one-act festival. Most all of the one-acts were staged so that they had two scenes--one stage right and one stage left. The lighting designer (not me) decided to divide the stage in two right down the centerline. However, he wasn't very careful with his focus, and we ended up with random triangles of bright and dark spots running all up and down the centerline.

    One good 'rule of thumb' is what steve shelly calls the "slinky method." You focus your ellipsoidals so that the center of each area is covered by the field angles of the ellipsoidals used to cover the area, and the area in between two areas is covered by the beam angles of the instruments used in lighting both areas. That way, each spot on stage (assuming a standard 45-45 frontlight system) is either in the hot spot of two instruments or in a slightly dimmer beam of light from four.

    Also, I cannot stress enough how important it is to have someone standing on stage while you're focusing, otherwise you tend to focus on the floor, which is great if your pastor is about 1' tall, but I'm assuming he's a more normal height. Basically, having a "walker" lets you see how the light is going to look on someone's face, which is what you typically care about anyways. If you're worried about the view from the cameras, I might even try to bring them in while you're focusing, so that you can check how your wash looks right away.

    Finally, and this is just a point of curiosity and totally unrelated to lighting, but you said that your church has 1500 seats. This seems extremely large to me. How does it feel to be a part of such a large congregation? My church youth group visited Grace church in the Minneapolis area (I can't remember which suburb exactly) and it felt much more like a theatrical performance than a worship service. What has been your experience with this?
     
  20. Peter

    Peter Well-Known Member

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    Sqiglish, I am not sure I am completely following what you mean with the slinky method (yes, sorry, I know I am slow, but it has been a long day). How would one area be covered by 4 lights in the way you are describing? Maybe MS paint would help if you want to e-mail me a pic i'll put it on my server to link here (or dave could do the same thing) or if you just want to try again in words.

    I am curious b/c currently @ my school our lights dont overlap too much and I am wondering if there is a better way to set them up. (I have just always set things up by the seat of my pants, haveing no training or reference materials to work from).


    And to continue the sub thread here abit, I cant really imagine a church with 1500 people. My "Church" has about 1500x10^-3 people (15 for those of you who cant read inproper scientific notation). Our Meetings are FAR from a performance, just honest remebrance!
     

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