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Lighting a slow-mo macro shoot with Red Epic – HMI or tungsten?

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Stephen Kennedy
Lighting a slow-mo macro shoot with Red Epic – HMI or tungsten?
on Oct 14, 2013 at 5:20:41 am

Hi,

I'm preparing a shoot and need some lighting advice.
I'm planning to shoot very small objects, mostly in liquid tanks using the Red EPIC at frame rates up to 300fps, and the Canon MP-E 65mm f/2.8 1-5x Macro lens with as much depth of field as I can muster to get the most detail.
What I'm wondering is the best way to light the scene: cheaper tungsten lights, or HMIs?
Here are the factors involved:

1. Both the high frame rate and wide depth of field demand a LOT of light
2. The area I need to light, however, will be very small – at largest, perhaps around the size of a golf ball – so I need lights that I can focus, if possible, to get maximum efficiency
3. I do not need especially need daylight temperature since what I'm shooting is quite abstract, so wouldn't need to lose the normal stops CTB would inflict on tungsten.
4. If at all possible I would like to be able to operate on mains power rather than need a generator.

I've consulted a lighting company who have suggested and quote me to use 2.5k HMI lights, which are £300 a week each including ballast, stands etc. I'm on a relatively tight budget, so I need to really understand whether I'm going to need the HMIs, or whether I could get away with using tungsten lights, which are obviously massively cheaper. I would really appreciate the experience of this forum.

So here are my questions:

1. Is there some way I can effectively calculate how much light I'm actually going to need prior to shooting, based on knowing the framerate, lens+f-stop and dimensions of the area I want to light?
2. Are HMIs the only way to go with shooting light this, or can I get away with tungsten?
3. Does anyone have any suggestions/experience lighting/shooting something similar, and can perhaps suggest an alternate way of doing it?

All help massively appreciated. Thanks for taking the time to read this.

SK


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Angelo Lorenzo
Re: Lighting a slow-mo macro shoot with Red Epic � HMI or tungsten?
on Oct 15, 2013 at 3:36:37 am

1. pCAM (it's an app for the iphone). Lights will have lumen/footcandle ratings for certain distances and focus spreads. pCAM has all the calculators to determine lighting needs from there.

2. I would go tungsten. You won't get flicker free operation at 300fps from HMI lighting. Because tungsten bulbs use actual heated filaments, you get a consistent light which aren't susceptible to flicker nearly as much.

3. I would consider a tweenie light (650w equivalents), and some dedolights (200w usually). This issue isn't so much the amount of light as you can position lights quite closely in a macro situation, but you'll need smaller sources like the dedolights and a lot of cutters/barn doors/cinefoil to shape the light in any meaningful way.

--------------------
Angelo Lorenzo

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Stephen Kennedy
Re: Lighting a slow-mo macro shoot with Red Epic � HMI or tungsten?
on Oct 15, 2013 at 4:06:00 am

Hey Angelo, thanks so much for your response to my questions.

1. pCAM looks amazing, downloading now. Don't know how I didn't know about that app, but look indispensable.

2. The rental house I've been speaking to said this:

I would think that as you are speeding up to 300fps, then the normal 2.5 MSR would do the job at close quarters and run off the local plugs, there is however a high frequency ballast that goes with the 2.5kw MSR ( we would have to hire in these at a modest cost) which runs at 1000 hertz for even higher frame rates, but if you stick at below 500 fps you should not experience any flicker.


So he's saying I should be fine as long as I stay under 500fps. Do you think that information is wrong?

3. I have a fair amount of experience with Dedolights, so they were actually my first thought, I've just been pushed in the direction of HMIs because of my concern for the sheer quantity of light needed. Perhaps I need to rethink. I wish I had a larger budget to actually conduct some experiments, but I don't really, I need to get it right first time if I can.

Thanks for your help.

S


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Angelo Lorenzo
Re: Lighting a slow-mo macro shoot with Red Epic HMI or tungsten?
on Oct 15, 2013 at 5:09:14 am

Well if you have a high speed solid state ballast then I say HMI is viable - many rental houses don't usually have them available. I always feel like their performance isn't perfect so I always expect a little residual flicker but maybe I'm crazy.

Also, rereading your initial post I didn't realize you wanted to go deep with your aperture. 300fps @ f/16 would be an EV value of 17.

A little back of the envelope calculation with an Arri 2.5k at full spot at 10 ft (3.3m) is 4213 footcandles.

pCam states that for proper exposure for 300fps, f/16, iso 800, is 3000 footcandles. The 2.5k would be more than enough (at least this particular model).

Again, if you're working with the lighting much closer then you can go with lower wattage. Just keep the inverse square law in mind; you can gain 4 stops just from moving lights in from 10ft to 2.5ft.

--------------------
Angelo Lorenzo

Need to encode ProRes on your Windows PC?
Introducing ProRes Helper, an awesome little app that makes it possible
Fallen Empire Digital Production Services - Los Angeles
RED transcoding, on-set DIT, and RED Epic rental services
Fallen Empire - The Blog
A blog dedicated to filmmaking, the RED workflow, and DIT tips and tricks
Can your post production question fit in a tweet? Follow me on Twitter


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Emre Tufekcioglu
Re: Lighting a slow-mo macro shoot with Red Epic HMI or tungsten?
on Oct 15, 2013 at 10:34:04 pm

To add on Angelos calculations you might want to consider using a Nila light as opposed to traditional HMI or Tungsten lights.

-A Nila light can be either daylight or tungsten
-Cool to the touch, very good on tight spaces.
-Flicker free up to 1500fps
-Fully dimmable (%0-%100)
-Extremely low draw, 2500W HMI equivalent draws 500W.

http://nila.tv/

Hope this helps,
Emre
http://www.productionpit.com



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Angelo Lorenzo
Re: Lighting a slow-mo macro shoot with Red Epic HMI or tungsten?
on Oct 16, 2013 at 7:23:55 pm

I'd be careful about dimming. I've had "flicker free" dimmable LEDs show heavy flicker between 0-50%; some more than others including Arri and Mole Richardson. I would rely on using them at 100% and then using scrims/nets or ND gel.

--------------------
Angelo Lorenzo

Need to encode ProRes on your Windows PC?
Introducing ProRes Helper, an awesome little app that makes it possible
Fallen Empire Digital Production Services - Los Angeles
RED transcoding, on-set DIT, and RED Epic rental services
Fallen Empire - The Blog
A blog dedicated to filmmaking, the RED workflow, and DIT tips and tricks
Can your post production question fit in a tweet? Follow me on Twitter


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