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#1 jonathan grant

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Posted 28 May 2007 - 02:03 PM

In my first film I had to use a cheap lighting set, i.e. worklights hooked up to dimmers. They worked great! Now I'm in preproduction for a TV show and have access to a for real lighting set with 1ks and 2ks. But I really miss the control I had with the dimmers. Can you plug the lights into dimmers or will it make them blow up or something? I've never seen lighting people use dimmers with them but I much prefer having dimmers. Is it okay to do that or is there a reason why they don't do it?
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#2 Hal Smith

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Posted 28 May 2007 - 02:39 PM

In my first film I had to use a cheap lighting set, i.e. worklights hooked up to dimmers. They worked great! Now I'm in preproduction for a TV show and have access to a for real lighting set with 1ks and 2ks. But I really miss the control I had with the dimmers. Can you plug the lights into dimmers or will it make them blow up or something? I've never seen lighting people use dimmers with them but I much prefer having dimmers. Is it okay to do that or is there a reason why they don't do it?

They're used all the time on stage with all sorts of tungsten fixtures. Stick with heavy duty name brands like ETC, Strand, etc. and you'll do just fine (in the more garage band genra, the Lightronics dimmers aren't too bad, I use them for practicals). You do know that the color temperature warms as you dim a lamp? With video gear you can white balance out CT shift but if you have different lamps dimmed considerably different amounts you might have trouble getting everything to look right.
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#3 Michael Nash

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Posted 28 May 2007 - 03:36 PM

Just make sure to use a dimmer that's rated for the wattage of the light you're using. Tabletop dimmers like this are usually only good fro 300 watts. Typical "hand squeezer" type dimmers you get from rental houses are usually only rated for 1K (often called 1k dimmers or squeezers). For 2K and larger lights you'll often end up using a Variac, again rated for the wattage.

http://www.cinematog...csvsDimmers.htm

And of course dimming (lowering the voltage) changes the color temperature, but you can often get away with about a 1/2 stop change without horrible color artifacts. Another problem with dimming is that it can make the lamp start to audibly buzz, which can cause sound problems.
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#4 timHealy

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Posted 28 May 2007 - 03:46 PM

Why would you think dimmers would make lights explode after using them succesfully yourself?

Hal is right, dimmers and dimmer systems are used for just about every standing set built. It makes turning lights on and off and finding the right intensity levels very easy. And if you have any wacky effects or chases. Also very important as specialty lighting light LEDs need many more DMX channels than your average tungsten lights.

Some producers and production managers will try and chisel the number of packs down because they can get expensive. But the gaffer and Dp need to impress upon them how fast it will help shooting and it would be cheaper in the long run.

Best

Tim
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#5 jonathan grant

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Posted 28 May 2007 - 03:47 PM

So you are from Edmond huh? Small world! We will be filming a lot in Edmond. I'm from Norman but the other two producers are from Edmond.

Thanks for the help guys! Exactly what I was needing. :)
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#6 jonathan grant

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Posted 28 May 2007 - 03:49 PM

Why would you think dimmers would make lights explode after using them succesfully yourself?


I didn't think that would happen, but the guy who originally lent us a lighting kit didn't want us to use the dimmers because he was afraid they would short them out or something. That didn't make sense to me, but just wanted to make sure anyway. We're using someone else's lights now. :)
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#7 Hal Smith

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Posted 29 May 2007 - 10:10 AM

So you are from Edmond huh? Small world! We will be filming a lot in Edmond. I'm from Norman but the other two producers are from Edmond.

Thanks for the help guys! Exactly what I was needing. :)

What's up? Shoot me a PM and we'll chat.
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#8 Bob Hayes

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Posted 29 May 2007 - 11:19 AM

Dimmers are great and I use them all. When I have time I try to scrim down the lights and use the dimmer for fine tuning adjustments.
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#9 jonathan grant

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Posted 29 May 2007 - 07:29 PM

I emailed you :)
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#10 Matthew Parnell

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Posted 29 May 2007 - 07:58 PM

For tungstens its always good practice to warm up ur lamps at 100 percent for 5 or 10 mins before dimming otherwise you do risk lowering the life of the bubble. This is especially a good idea if you are flashing or consistantly changing the dimming level of your lamp because not only do you tend to reduce the life but they tend to blow much easier when flashed on and off cold.
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#11 Sing Lo

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Posted 02 June 2007 - 07:26 PM

A dimmer actually lengthens the bulb life if it sets at about 70% dimming because the filament operates at lower temperature. It only shortens the bulb life if
you turns the dimmer very quickly; the filament gets thermal shock if the current suddenly changes rapidly.

I wonder if anyone ever stacks both a double wire scrim and a single scrim in front of a fresnel lens?? I wonder if it will create Moire pattern (optical interference between the two scrims meshes) ?
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#12 David Auner aac

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Posted 03 June 2007 - 03:46 AM

I wonder if anyone ever stacks both a double wire scrim and a single scrim in front of a fresnel lens?? I wonder if it will create Moire pattern (optical interference between the two scrims meshes) ?


Hi Sing,
I do that all the time in my Arri fresnels. Why should you get a Moire pattern? You don't see the shadow of the wire guard either since the whole affair is so close to the lens! The only situation where it could be possible to get such patterns was when the scrims are a couple of meters away from the lens and the lit subject just a couple of centimeters behind the scrims. Not sure it would happen there either, because the beam of light emitted from the light is rather large, so the shadows wouldn't be sharp enough.

Cheers, Dave
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#13 Sing Lo

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Posted 03 June 2007 - 02:27 PM

Hi Sing,
I do that all the time in my Arri fresnels. Why should you get a Moire pattern? You don't see the shadow of the wire guard either since the whole affair is so close to the lens! The only situation where it could be possible to get such patterns was when the scrims are a couple of meters away from the lens and the lit subject just a couple of centimeters behind the scrims. Not sure it would happen there either, because the beam of light emitted from the light is rather large, so the shadows wouldn't be sharp enough.

Cheers, Dave



HI DAVE, That makes sense, I forgot that the scrim close to the lens won't create shadows anyway. :lol: I have been experimentating stacking two large mesh cookie patterns (homemade) placed two meters in front of a fresnel, it creates some very funky Moire pattern.
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