Jump to content


Photo

What lights to not point straight up or down?


  • Please log in to reply
6 replies to this topic

#1 Ricardo Casco

Ricardo Casco
  • Basic Members
  • PipPip
  • 15 posts
  • Grip
  • Houston

Posted 20 May 2012 - 09:34 AM

I know some Arri fresnels don't like being pointed straight up or down, at least the older ones. I only have Moles, are there any moles that have the same issue? What about Desisti and other brands (LTM)?
  • 0

#2 Victor Bareno

Victor Bareno
  • Basic Members
  • PipPip
  • 10 posts
  • Student

Posted 20 May 2012 - 03:11 PM

pretty sure this applies to all fresnels, I heard it referenced as an elementary mistake one time. Probably because heat rises, and the fixtures cant allow the heat to escape properly at those angles. But I could be wrong.
  • 0

#3 Rob White

Rob White
  • Basic Members
  • PipPip
  • 24 posts
  • Electrician
  • London

Posted 30 May 2012 - 11:31 AM

Pretty much as Victor says, if you point a fresnel straight up the heat can't escape through the lens (which can cause it to crack when it gets too hot); and if you point straight down, you get the same problem with the reflector - which will warp, melt, catch fire or explode, depending on mood.

I think the newer Arri true blue stuff has better airflow/more resistant materials so it's less of a problem. Also, K5600 fresnels tend to use ceramic reflectors so you can point them straight down with impunity. Can't point them straight up though, as the lens is still a problem.
  • 0

#4 Ricardo Casco

Ricardo Casco
  • Basic Members
  • PipPip
  • 15 posts
  • Grip
  • Houston

Posted 30 May 2012 - 01:01 PM

pretty sure this applies to all fresnels, I heard it referenced as an elementary mistake one time. Probably because heat rises, and the fixtures cant allow the heat to escape properly at those angles. But I could be wrong.



Pretty much as Victor says, if you point a fresnel straight up the heat can't escape through the lens (which can cause it to crack when it gets too hot); and if you point straight down, you get the same problem with the reflector - which will warp, melt, catch fire or explode, depending on mood.

I think the newer Arri true blue stuff has better airflow/more resistant materials so it's less of a problem. Also, K5600 fresnels tend to use ceramic reflectors so you can point them straight down with impunity. Can't point them straight up though, as the lens is still a problem.



Thanks, I figured as much. I'm curious now, does this also apply to the bulb? Will the bulb cause issues if its operated on its side, or maybe upside down?

And what type of rigging would you use say you wanted a light to be pointed straight down? I've never come across something like this
  • 0

#5 Brian Drysdale

Brian Drysdale
  • Basic Members
  • PipPipPipPip
  • 5070 posts
  • Cinematographer

Posted 31 May 2012 - 01:09 AM

And what type of rigging would you use say you wanted a light to be pointed straight down? I've never come across something like this


I've pointed a light straight down on a number of occasions. It's pretty easy to do with the smaller wattage light, but you'll need something to suspend the light from, say a polecat for lighter units, something more substantial for heavier lights. Although my use was with smaller units, it's best not to keep the light burning for long periods, just long enough for a take.
  • 0

#6 Rob White

Rob White
  • Basic Members
  • PipPip
  • 24 posts
  • Electrician
  • London

Posted 31 May 2012 - 05:38 AM

I'm curious now, does this also apply to the bulb? Will the bulb cause issues if its operated on its side, or maybe upside down?


You would generally want to keep the heat away from the the globe's mount, so it's best not to burn them upside down. You might also risk damaging the focusing mechanism. As for sideways I couldn't see it being a huge problem, probably wouldn't want to do it for too long though, as you're still subjecting the mount to additional heat.
  • 0

#7 Ricardo Casco

Ricardo Casco
  • Basic Members
  • PipPip
  • 15 posts
  • Grip
  • Houston

Posted 31 May 2012 - 06:21 PM

You would generally want to keep the heat away from the the globe's mount, so it's best not to burn them upside down. You might also risk damaging the focusing mechanism. As for sideways I couldn't see it being a huge problem, probably wouldn't want to do it for too long though, as you're still subjecting the mount to additional heat.


Ok thanks, I've been attempting to build a lantern out of some spare arri parts, I'll make it with the bulb upright. This is just a DIY project (maybe to make some profit out of), I'm still looking at chimera lanterns!
  • 0


Wooden Camera

FJS International, LLC

Glidecam

CineTape

Visual Products

Tai Audio

Aerial Filmworks

Gamma Ray Digital Inc

Technodolly

The Slider

Media Blackout - Custom Cables and AKS

Paralinx LLC

Ritter Battery

Metropolis Post

CineLab

Rig Wheels Passport

Broadcast Solutions Inc

rebotnix Technologies

Abel Cine

Willys Widgets

Opal

Wooden Camera

Visual Products

FJS International, LLC

Abel Cine

Rig Wheels Passport

Opal

Aerial Filmworks

Gamma Ray Digital Inc

Glidecam

Ritter Battery

Paralinx LLC

Willys Widgets

Tai Audio

Technodolly

Media Blackout - Custom Cables and AKS

CineTape

Broadcast Solutions Inc

rebotnix Technologies

Metropolis Post

CineLab

The Slider