Bat Lights (Batten Lights)

3rd January 2005

Hello all.

OK so I've heard a little about these...bat lights.

Sounds like lots of small lamps on a strip that can be hung?

Does anyone feel like letting me in on the secret? Have they been around for a while? What sort of lamps do they use? And when do you use them?

Cheers.

John Brawley
DOP
v:media
Melbourne Australia

>OK so I’ve heard a little about these...bat lights.
>Sounds like lots of small lamps on a strip that can be hung?

Unless this is a Gotham City-specific thing, I would guess that "bat lights" are referring to

BATTEN STRIPS

Generally batten strips are constructed by taking a 1" x3" wood batten (or 5/4" x 3" in New York) and screwing surface-mount porcelain medium screw base sockets to it on one foot centres or so. You can use them with EAL's or other color correct photofloods (R40 reflector globes) or you can use them with regular A lamps or PS lamps.

They can be used in front of diffusion or to light a backing that is too close to light with scoops or bigger fixtures - say outside a window on a set that is built too close to the wall (not that this ever happens)

They can also be used in building soft boxes or book lights- bouncing them into the back of the box, for instance.

I haven't used them much myself, having built a few sets over the years...I think the last set I built was for a scene that involved a long walk under a covered walkway - we screwed them to the sides of the cross-members of the walkway every so often so the actors would go through patches of light - more front lit than back lit as they got close to them -

In this case, I just used 150 watt PS (stands for pear-shaped) lamps - for a soft mushy light - Kinda like a KinoFlo on steroids.

If you think of the classic Broadway or Hollywood makeup mirror with a string of bulbs around it, you can get some other ideas about ways they can be used.

One of the interesting things about batten lights is the nature of the shadows that are created by them - depending on lamp spacing and what sort of lamps you use, and the distance between subject and lamp and background (or floor) you can either get a bunch of shadows or just a soft mushy linear area of less intensity - and being a line source, the fall-off as you move away from them is different than the fall-off from a point source

For very little money, you can get the bits together to build one or two at the local DIY place or Home Despot - if you have the time, make one up and play with it with normal household bulbs and see what it can do for you.

I have found that when I did build them, I would then store them for seven or eight years, finally give them away or throw them out, and then have to build a set again a few years later. I gave my last set to someone else who will now store them for a few years before throwing them out and then building them again.

Mark Weingartner
LA based

I have also seen people using these as a broad backlight across a room.....pushed up to the cornice of a room and diffused. Dante Spinotti uses a gee whiz version of these...a cross between the bat light and ministrips. His version used PAR 16 bulbs and was used a fair bit on his later films..."Wonderboys" and "The Insider" I believe.

You can also use them vertically in a corner. I guess they are a Kino with punch for lovely hot edges with limited room.

Nick Paton
Director of Photography
High Def./Standard Def./Film
Aaton XTR Prod owner operator
Brisbane, Australia
www.npdop.com

This discussion reminds me that I'd like to do some tests with a cross- or X-shaped arrangement of linear light sources (either flo tubes or bat lights, crossing at right angles) to see to what extent they behave like a square diffuse source of the same overall dimensions.

If you're lighting, say, one side of a face with them, the amount of horizontal and vertical wrap would be the same as from a square source. But the look (apart from X-shaped reflections from specular convex surfaces) should be different. Has anyone tried this??

Dan Drasin
Producer/DP
Marin County, CA

>This discussion reminds me that I'd like to do some tests with a >cross- or X-shaped arrangement of linear light sources

Well this is what really intrigued me about this type of light source when I heard about them.

I really also like the idea of a flexible source too. I am just imagining that you could string them about and form the shape to what ever suits. Having the power supply / Ballast separate means they are easy to dress and hide in shot.

When I heard about them the DOP was using them in a semi circular shape from above to control the spill and mould the light across a two shot profile.

Now to just work out the light source and distances ! Are we agreed then that MR16's are the source of choice ? Is it simply because the have a small profile and depending on the bulb, have a narrow beam angle ?

Any clues on number and distance. I'm all for playing of course, but would be interested in hearing other's experience.

John Brawley
DOP
v:media
Melbourne Australia

>Now to just work out the light source and distances! Are we agreed then >that MR16's are the source of choice?

My reference to Dante Spinotti's use of bat light types of fixtures mentioned Par 16 lamps...I haven't seen them here but they are like shrunken sealed beam Par 64s and not like the MR16s we find in down lights and the like.

Nick Paton
Director of Photography
High Def./Standard Def./Film
Aaton XTR Prod owner operator
Brisbane, Australia

Indeed they seem to be a bit hard to come by in *this* part of the world.

But it seems they essentially do the same thing as an MR16 except they are mains operated ????

Anyway, I'm all inspired now to rush out and build me a couple'a Bat lights !

I do like the idea that they might be mounted on a semi-flexible base, so I'm going to have to think about how to do that safely. But I think it sounds a lot more interesting than just throwing them onto a bit of timber.

There are even MR16 fixtures that allow the lamp to be positioned and focussed. That may even add a further focusing dimension. I'm sure I won't know what to do with myself.

John Brawley
DOP
Vicious Media
Melbourne Australia

>Are we agreed then that MR16's are the source of choice ? Is it simply >because they have a small profile and depending on the bulb, have a >narrow beam angle ?

Hi Nick, Jim, John,

I know I am way late to the conversation about bat lights and you may already have your answers but here is what I have.

I had the pleasure of day playing as an Set electric on Wonder Boys just for the chance to observe Dante Spinotti working with light. He used bat lights everywhere for interiors mounted vertically, horizontally and diagonally.

Always on a variac and dimmed for a low color temp (2600K ish). Jay Fortune was the CLT and brought many of his own bat strips, the standard New York style (1" x 3" or 4" with porcelain sockets) in varying lengths. Early on in the show there was a genesis of the bat strip and the fixtures used. They switched to use the Sylvania Capsylite Designer 16 ( hence the confusion) NFL (Narrow Flood) 75 watt 30 degree beam angle. This light is a sealed beam Par 16 with a 2 inch stippled front lens. The CRI is 100 with a color temp of 2950K.

The entire light except lens and base is porcelain to withstand the massive heat generated. The lights were spaced evenly across the 1 x 3 board with just enough room to screw in the bulb. The problem was the bats fully loaded weighed too much for the board, they would flex unless secured in multiple points. I am not sure whose idea it was but it was decided to create an I beam like fixture made from welded aluminium. They were 4 feet long with 2 baby spuds welded on each end of the backside channel which also helped contain the wiring which is always a pain with the bats. The draw back to these newly designed lights was it always took two people to hang them or adjust them. They do however have a narrow profile and put out a beautiful light. By the end of the show there would be upwards of 25-30 units playing throughout a set!

I must add that Dante was the nicest D.P I have ever worked with. He constantly offered up unsolicited information about what he was doing and why. He would often say "you want a little of that learning you came here for?" Of course we (crew) would say "sure". He by the way was using the Beta version of the KLMS ( different name?) at that time, very cool.

I recommend for anyone who shoots and lights to get on other D.P's sets (if you can) to see what they are doing. This will help you from falling into a routine of lighting all of your stuff the same way.

Hope this helps.

Ted Wiegand
Dir/D.P
Pittsburgh, Pa.

Ted Wiegand wrote :

>it was but it was decided to create an I beam like fixture made from >welded aluminium.

I'm curious how this differs from the Decapod available through Mole :

http://www.mole.com/rentals/decasource/decapod.html

Sounds like a homemade version of that, or maybe I'm missing something?

They sound cool, either way. I loved "Wonder Boys", great movie.

Phil Badger
gaffer, LA
http://home.earthlink.net/~badger111/index.html

Phillip Badger wrote :

>I'm curious how this differs from the Decapod available through Mole:

It's about a $50 a day difference...

Especially since Mole doesn't tend to do deals.

Craig Kief
Gaffer/DP
Los Angeles based

A couple of notes about bat(ten) lights, aka cleat lights - after the name of the porcelain sockets known as cleat sockets.

Using a 1x3 wooden batten means the unit can be easily cut to fit wherever it needs to be fitted -- it's only a batten and the only tool required is a Swiss Army knife with a saw blade or a Leatherman, etc.

Using heavier bulbs will of course bow the batten. Uneven drying from the heat of the lamps will also unevenly dry the wood. As an alternative, we used 2x4s or 2x3s., they can still be cut with a pocket tool, it just takes a little longer.

A couple of safety tips : the total wattage/amperage of these units can increase very rapidly when you start to up the bulb wattage, and has been noticed, they can and often do, get extremely hot. Hot enough to melt the insulation off the light weight zip cord that is often used to make up these fixtures.

It's really worth the trouble to use a temperature rated fixture wire like THHN in these units and then properly attach a length of S or SJ cord -- stranded THHN is not designed for continual flexing.

History of batten lights :

Years ago, it was not uncommon to see 500 watt EAL photofloods in these fixtures. Of course, asbestos cloth and board were also readily available then. There was always a roll of asbestos cloth on the truck. (People also smoked on the set.) I was told that they used to use 1000 watt or 1500 watt or even 2000 watt mogul based bulbs in batten lights but thankfully I never saw one in use.

A very clever key grip used to make batten lights out of three 1x3s glued and screwed into a "U" shaped channel. This kept the board from bowing as it dried, and protected the porcelain cleats from breaking during shipping (loading by the teamsters). The electricians then wired them using HPN or heater cord - a high temp two conductor cord that looks like zip cord.

Brian "Do you smell something burning?" Heller
IA 600 DP

>A very clever key grip used to make batten lights out of three 1x3s glued >and screwed into a "U" shaped channel...

U-channel is a great idea for protecting the sockets as well as strengthening the flex factor of the batten.

The wiring can also be done with Teflon coated, high temperature wire but I'm not certain if that is available in solid rather than stranded.

Never use regular zip cord as that is the most susceptible to heat. I use #12 gauge THHN solid because the ampacity of the wire (#12 is 20A) is rated on it's heat dissipation qualities usually based on an ambient temperature of 86F degrees. When you enclose the wire in a heated box you have drastically changed the conditions for which the wire was rated. Then the ampacity of the wire decreases. The maximum temperature rating for THHN is 194F degrees.

Proper venting of any foamcore enclosure is also critical to keeping the temperature down inside any box made around the batten unit. We would even use small fans on the ends of a batten box to circulate air between takes.

> -- it's only a batten and the only tool required is a Swiss Army knife with >a saw blade or a Leatherman, etc.

Or a saw.

Jim Sofranko
NY/DP

>I recommend for anyone who shoots and lights to get on other D.P's >sets (if you can) to see what they are doing.

It's nice when possible, and I've learned a lot from observation (and you can never learn enough-it's great when others can share a common enthusiasm) I had a chance to very briefly meet with CML-er Fortunato Procopio(forgive the spelling if I missed it)on the set of his recent project and it was great to be able to take a quick peek, observe lighting conditions and decisions- you can always learn more, compare your own decisions in that same situation, etc.

John Fonseca Babl
DP
Miami & Brazil

Jim Sofranko writes:

>Or a saw.

An actual hand saw that could cut wood seemed to be the most difficult tool to keep on the set, and the carpenters were so possessive of theirs.

You know, you're up on a ladder and you ask for a saw and the carpenter
says: "Pass the batten down and we'll take it outside and cut it, but you have to get all these wires out of the way, and btw, we need another extension cord for the mitre saw, because our truck is parked on the other side of the building."

By the time they're back with the board, you could've gnawed through it

I keep an SAK in my pocket...

Brian Heller
IA 600 DP

>By the time they're back with the board, you could've gnawed through it

Nowadays the cordless saws are the trick but they take a bit to retrieve from the case and all. I just never got the hang of those Leatherman tools.

I know some people swear by them but I always ended up swearing at them.

Jim Sofranko
NY/DP

>Nowadays the cordless saws are the trick but they take a bit to retrieve >from the case and all. I just never got the hang of those Leatherman >tools.

The merits of doing serious electrical work with an all metal tool are dubious at best. The other problem being that multi-tools are definitely a jack of all trades, but master of none.

On the other hand, multi-tools are handy in an absolute emergency and as posing gadgets along with the obligatory Maglite harness and unfeasibly baggy shorts.

Clive Mitchell
http://www.bigclive.com

Clive Mitchell writes:

>The merits of doing serious electrical work with an all metal tool are >dubious at best. .

Ah, Clive. I am much for safety as the next guy, but we are talking about cutting piece of a wood…

Brian Heller
IA 600 DP

>Ah, Clive. I am much for safety as the next guy, but we are talking about >cutting piece of a wood…

Balsa wood I assume with your reference to a multi-tool. :P

The only multi-tool I'd consider using for such a task would be the Gerber that takes standard jigsaw blades. I'd remove the blade, stick it in an electric jigsaw and be through the wood in no time.

Now be honest. Have you actually cut through a significant wooden batten with a multi-tool's saw blade? I mean, perhaps if it was a two foot long Leatherman with a full size forestry attachment.... It's bad enough trying to cut a bit of resinous wood with the electricians trusty pal the hacksaw.

Clive Mitchell

Clive Mitchell writes:

>Now be honest. Have you actually cut through a significant wooden >batten with a multi-tool's saw blade?

Yes, and I do it regularly. I can't speak for all multi-tools. Only a Victorinox Swiss Army Knife. I'm quite serious that I can usually cut the 1x3 nominal (3/4" x 21/2") pine batten by the time somebody comes back with a saw. It usually takes less than 30 seconds. It's not magic, the SAK has a very high quality saw albeit quite small. I'm not suggesting building a house with one, or even cutting 2x4. Obviously, if a real hand saw was nearby, it would be faster. BTW, this started with a discussion about permanent (aluminium) bat lights being somewhat of a contradiction.

>I mean, perhaps if it was a two foot long Leatherman with a full size >forestry attachment....

Come on Clive.

>It's bad enough trying to cut a bit of resinous wood with the electricians >trusty pal the hacksaw.

Most electricians I know seem completely unaware of three facts:

First ... that hacksaw blades get dull;

Second ... that the blade can be replaced for about a dollar without having to buy a whole new saw;

and Third ... that there is a difference between cutting wood and metal; and that when used without a cutting fluid, aluminium will permanently clog a hack saw blade.

Disclaimer : I have no interest in Victorinox, but I have found that a SAK to be extremely handy around movie cameras.

Brian Heller
IA 600 DP

P.S. We're snowed in here so before I loaned my neighbour’s kid another shovel I asked him to cut a batten with
my SAK. Total elapsed time: 27 seconds.