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Lighting and Watts


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Theoretically, they would put out the same number of total footcandles as a 1K. In practice it depends on the actual lamps. What are you trying to do?

 

If you're asking does the stop double, it would. The stop will increase by one everytime you double the light output.

 

If 500 watts= t/2 then

1000 watts= t/2.8

2000 watts= t/4

4000 watts= t/5.6 etc.

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Guest Daniel J. Ashley-Smith

You know it amazes me the amount of power in studio lights. Up to 4k and only increasing by a few stops every 500 watts??!! I have a flood light in my back garden and that rates 500 watts, and man is it powerfull.

 

I would have thought with that amount of light the model/actor would be squinting a lot.

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Hi,

 

I think that was just an example, and of course it makes a huge difference how far you are from the source.

 

And yes, shooting film does require utterly silly amounts of light unless you're using fast stocks. Much squinty.

 

Phil

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YOur eyes are playing tricks on you. It's because there is a huge contrast between night ambient light (city lights hitting the haze, moon, nearby street lights) and your 500W lamp. It is not nearly powerfull as it seems.

 

And not "few stops" every 500W. In theory it would be ONE stop for every double value. That is double Wattage from the same series of lamps from the same manufacturer. (500W does not always give the same amount of light from different models and manufacturers, and of course types of lighting).

So In theory one stop would be the difference between 4000w and 8000W

and allso 2000W and 4000W, 20W and 40W etc.

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If you're asking does the stop double, it would.  The stop will increase by one everytime you double the light output.

 

If 500 watts= t/2 then

1000 watts= t/2.8

2000 watts= t/4

4000 watts= t/5.6  etc.

 

 

This was purely an example of the ratio between light output and t/stops. Not an actual stop for those lamps.

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Thanks a lot guys. The reason I asked is that I'm looking to make some shorts with low budget, and the highest wattage I can buy a lamp at at Lowes is 500 watt. I was just wondering if I could save several hundred dollars by buying a few of these and not a 1k fresnel, for example.

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Hi,

 

Well, you could probably do that. It won't be as controllable as the real deal, but after a certain point light is light and it just comes down to different ways of shaping it, many of which could be applied to 500W halogen floods.

 

Phil

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I was just wondering if I could save several hundred dollars by buying a few of these and not a 1k fresnel, for example.

 

Yeah - Buy a few of these, they will certainly come in handy here and there. Get lots of extension cords and power splitters. However, as stated, these lights really are a bitch to control, and if you haven't the money for a fresnel (which are quite expensive), consider PAR64 cans.

 

1k power, and while you can't control the beam focus, you can buy bulbs ranging from flood to verry narrow spot.

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Hi,

 

Google for the places that supply theatres (stage theatres not cinema theatres) and event lighting. All the gel ranges tend to include correction, and these are the people who'll have parcans and the like. Parcans are pretty OK, although they lack barn doors, and they're very cheap - the whole unit including yoke, scaff clamp and lamp tends to be around £50, probably meaning it'll be around $50 there, grumble!

 

Phil

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Hi,

 

Bah, if I want parcans I'll borrow some off one of the outfits I know who do stage and event stuff. On the icicle-coated hades morning when I get to shoot some film and need a billion kilowatts of light, it's very likely to be mostly parcans because I can get them cheap!

 

Oh, and that one is without lamp (£25) so by the time you've shipped it, yep, about fifty quid!

 

Phil

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What's the "snout" of the parcan? What's a WFL lamp? What's a little extra speed? Sorry, I'm not to experienced with parcan lights. Or any lights, for that matter. I've used ARRI fresnels, but that's about it.

 

 

Well, we're talking about theatrical PAR 64 cans also known as "Rock and Roll" PAR cans and they carry a 1000KW PAR lamp. PAR is an acronym for Parabolic Alumized Reflector, it's an all in one unit with reflector, lens and filament. Looks like old style car headlights if you seen those before. The fixtures look like this;

 

rockrollpar.jpg

 

You can cut the housing down to half length so it lets more light spread out. Actually you can buy short ones off the shelf but I find it just as easy to cut them down. The reason I like to cut them down is so they act more like a Molequartz PAR. When people on a film set refer to a PAR they usually mean one that looks like this one below (or one of the HMI types that look similar);

 

molepar.jpg

 

You can fit the housing with a variety of lamps. WFL = Wide FLood, MFL= Medium FLood, SP= SPot, NSP=Narrow SPot etc. Using a Wide FLood lamp will give you a nice area of light, because you usually use these things to light buildings etc. The biggest problem I have with them is the filament hotspot in the center of the beam. You can kill it with a dot scrim though.

 

Look at Mole's website to learn more.

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Hi,

 

You can get short PARcans which would save a little hacksaw work.

 

Any why is a birdie (a little miniature parcan which takes an MR16) called a birdie?

 

Because it's two below PAR....

 

Sorry, couldn't help it.

 

Phil

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