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What lights to not point straight up or down?


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#1 Ricardo Casco

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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)?
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#2 Victor Bareno

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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.
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#3 Rob White

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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.
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#4 Ricardo Casco

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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
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#5 Brian Drysdale

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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.
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#6 Rob White

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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.
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#7 Ricardo Casco

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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!
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