Scrims or Dimmers at DVinfo.net

Andrew Hogan · February 10th, 2005, 01:27 AM

I have just upgraded my light output from little Dedolights (came with dimmers) to Three x Arri 650 Fresnels. They're way brighter than the Dedos and don't have dimmers.

Buying Scrims and using them when they're hot must be a pain and not very controllable. Would cutting the Power cord and wiring in a Heavy duty Dimmer in the line be they way to go? Why don't they come with dimmers.

I supose when using 3 x 650w lights all at different dimmer settings there will be a white balance issue too?

Rick Bravo · February 10th, 2005, 08:22 AM

Dimmers will generaly change the color temperature of the light while scrims will only cut down the light intensity without changing the temp.

RB

Mark Montgomery · February 14th, 2005, 12:18 PM

Just curious, when dimming kino flos do you get a change in temp or just intensity. I've never used kino flos before and I'm just now thinking about it.

Andrew Hogan · February 14th, 2005, 11:40 PM

Seems quite a few people looked at this post but not much comments. So I have just bought a Four channel dimmer/controller. They looked like the ideal fix, they are generally used for small budget live band shows I'm told, and I got them at a Pro Music shop.

I have just tried them out and they look great and controll the light infinatley variable.

But! They are very noisy when you have any of the four channels dimmed. When all lights are on full the dimmer doesn't make a sound. Is it the voltage being dumped making the buzz. I'm worried that this sound will be picked up by the Mic.

I guess I'll have to put it in a different room than where the video is being shot. Or is it faulty?

Mark Montgomery · February 15th, 2005, 08:54 PM

Andrew,
Not faulty. At least not in my experiences with dimmers/controllers. Yes, you'll definitely have problems picking up those frequencies on your mic. They'll be a serious pain, in fact. Good luck with the results and good luck to us getting more timely responses, eh? I think I just heard this reply echoing within this thread. Seems so empty...

Just trying to stir things up a bit.

Allen Nash · February 16th, 2005, 09:15 PM

Dimmers aren't a good idea, because they'll change color temp (as mentioned) and this can lead to all kinds of problems involving continuity, or at very least it'll lead to a LOT more time spent adjusting colors in post. They also can fluctuate mid-shot or over time, and there's the hum to deal with.

Dimmers aren't often used in the professional film realm, for good reasons.

Scrims and silks/diffusion are the way to go. All cut down light intensity, but scrims preserve the edges of shadows (ie. hard or soft) while silks/diffusion will diffuse (soften) the edges, which is often times advantageous but should be implemented with an eye for what effect you're trying to achieve.

Scrims are the metal circle thingies, silks/diffusion are fabrics that are pre-determined sizes or other materials that can be cut like paper with scissors. They'll usually lower light intensity by a precise amount (ex. 1 stop, 2 stops, etc.) so they're easy to control. Trust me, you won't need to adjust the light by 1/15th of a stop.

Of course, the other alternative is to move the light farther away from the subject. You might get away with using a dimmer, but it's an unprofessional practice and if you plan to ever make movies for a living you might as well learn a better approach.

Andrew Hogan · February 18th, 2005, 12:37 AM

Thanks everyone. I'm gonna buy some scrims. Wish I hadn't bought the dimmer now.
The Dimmer/controller will be ok in some situations when continuity won't be a problem and I can have the noisy thing in another room.
Shooting in confined spaces and moving the light further away from the subject to get the intensity right usually wouldn't be possible.
Scrims and some thick leather gloves I think will work best.

cheers

February 10th, 2005, 01:27 AM	#1
Andrew Hogan Regular Crew Join Date: Nov 2001 Location: Canberra AUSTRALIA Posts: 169	Scrims or Dimmers I have just upgraded my light output from little Dedolights (came with dimmers) to Three x Arri 650 Fresnels. They're way brighter than the Dedos and don't have dimmers. Buying Scrims and using them when they're hot must be a pain and not very controllable. Would cutting the Power cord and wiring in a Heavy duty Dimmer in the line be they way to go? Why don't they come with dimmers. I supose when using 3 x 650w lights all at different dimmer settings there will be a white balance issue too?

February 10th, 2005, 08:22 AM	#2
Rick Bravo Major Player Join Date: Sep 2003 Location: Miami, FL Posts: 574	Color temp change. Dimmers will generaly change the color temperature of the light while scrims will only cut down the light intensity without changing the temp. RB __________________ "The future ain't what it used to be." Yogi Berra. www.rbravo.com

February 14th, 2005, 12:18 PM	#3
Mark Montgomery New Boot Join Date: Feb 2005 Location: Chico, CA Posts: 14	kino flos? Just curious, when dimming kino flos do you get a change in temp or just intensity. I've never used kino flos before and I'm just now thinking about it.

February 14th, 2005, 11:40 PM	#4
Andrew Hogan Regular Crew Join Date: Nov 2001 Location: Canberra AUSTRALIA Posts: 169	Seems quite a few people looked at this post but not much comments. So I have just bought a Four channel dimmer/controller. They looked like the ideal fix, they are generally used for small budget live band shows I'm told, and I got them at a Pro Music shop. I have just tried them out and they look great and controll the light infinatley variable. But! They are very noisy when you have any of the four channels dimmed. When all lights are on full the dimmer doesn't make a sound. Is it the voltage being dumped making the buzz. I'm worried that this sound will be picked up by the Mic. I guess I'll have to put it in a different room than where the video is being shot. Or is it faulty?

February 15th, 2005, 08:54 PM	#5
Mark Montgomery New Boot Join Date: Feb 2005 Location: Chico, CA Posts: 14	Andrew, Not faulty. At least not in my experiences with dimmers/controllers. Yes, you'll definitely have problems picking up those frequencies on your mic. They'll be a serious pain, in fact. Good luck with the results and good luck to us getting more timely responses, eh? I think I just heard this reply echoing within this thread. Seems so empty... Just trying to stir things up a bit.

February 16th, 2005, 09:15 PM	#6
Allen Nash Regular Crew Join Date: Apr 2004 Location: S.F., California Posts: 61	Dimmers aren't a good idea, because they'll change color temp (as mentioned) and this can lead to all kinds of problems involving continuity, or at very least it'll lead to a LOT more time spent adjusting colors in post. They also can fluctuate mid-shot or over time, and there's the hum to deal with. Dimmers aren't often used in the professional film realm, for good reasons. Scrims and silks/diffusion are the way to go. All cut down light intensity, but scrims preserve the edges of shadows (ie. hard or soft) while silks/diffusion will diffuse (soften) the edges, which is often times advantageous but should be implemented with an eye for what effect you're trying to achieve. Scrims are the metal circle thingies, silks/diffusion are fabrics that are pre-determined sizes or other materials that can be cut like paper with scissors. They'll usually lower light intensity by a precise amount (ex. 1 stop, 2 stops, etc.) so they're easy to control. Trust me, you won't need to adjust the light by 1/15th of a stop. Of course, the other alternative is to move the light farther away from the subject. You might get away with using a dimmer, but it's an unprofessional practice and if you plan to ever make movies for a living you might as well learn a better approach.

February 18th, 2005, 12:37 AM	#7
Andrew Hogan Regular Crew Join Date: Nov 2001 Location: Canberra AUSTRALIA Posts: 169	Thanks everyone. I'm gonna buy some scrims. Wish I hadn't bought the dimmer now. The Dimmer/controller will be ok in some situations when continuity won't be a problem and I can have the noisy thing in another room. Shooting in confined spaces and moving the light further away from the subject to get the intensity right usually wouldn't be possible. Scrims and some thick leather gloves I think will work best. cheers