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Cookies, HELP!


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#1 M Joel W

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Posted 23 April 2007 - 08:09 AM

I am shooting a scene in an office set (in my garage...so echoey it guarantees post-dubbing!) and I want light to be hitting the character's face like this

http://content.answe.../JackBlinds.jpg

but a finer pattern.

Here's my problem! I'm shooting between 40 and 80ISO at f2.0 (but I could do f1.4 if need be) and in color. The blinds will be covered with a FULL CTB...and the strongest light I have (save for open face 1ks) is a 650w fresnel!

If I put a cookie between the light and the actor's face it's always out of focus...unless I move it back, and then the light is WAY too dark.

So...

Where can I get a good cookie for venetian blinds? I don't know how big to make my pattern!

What do I do for a focusable light source! I can't afford a xenon, but I could maybe get a Par64 1k or a diachroic par. But how do I focus this? I've heard about focusable pars but uhh...where and how much?

Where do I find the legendary diachroic par64 bulb I may need...I've looked all over and can't find one for under $500! I hear this loses no light versus a 3200K par64, but burns out super fast. True?

Should I just give up?...

Thanks all!

Edited by Matthew Wauhkonen, 23 April 2007 - 08:11 AM.

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#2 Frank Barrera

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Posted 23 April 2007 - 08:12 AM

why are you shooting with such a slow speed stock?
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#3 M Joel W

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Posted 23 April 2007 - 09:01 AM

why are you shooting with such a slow speed stock?


Actually, it's a 35mm adapter plus the fact that I have to adjust my taking lens to f2.8-f3.4 to get decent sharpness....but as soon as I mention I'm shooting video people stop offering as helpful advice! That said, if I could I'd be all over Super 16.
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#4 Frank Barrera

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Posted 23 April 2007 - 09:22 AM

well, you have set up some parameters for yourself that will make creating that venetian blind effect very difficult if not impossible. as you have already discovered you need to be able to pull a single source far away enough from the cookie to give you the desired effect. a 1K is just not going to come close at a 60ASA to give you the exposure you need. you can:

a: get a bigger light (like a 5K if you're going tungsten)
b: get rid of the adaptor
c: come up on the gain
e: get rid of the adaptor AND come up on the gain

as for the cookie you can use a 4' x 4' empty frame and place either 1" or 2" black gaffers tape horizonatlly untill you get your desired look.

a PAR 64 could help. experiment with both a narrow and a medium lens. that will be very punchy and will get you closer to your stop. there's no need to "focus" it. just get the center of the beam on the subject's face.
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#5 M Joel W

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Posted 23 April 2007 - 09:37 AM

well, you have set up some parameters for yourself that will make creating that venetian blind effect very difficult if not impossible. as you have already discovered you need to be able to pull a single source far away enough from the cookie to give you the desired effect. a 1K is just not going to come close at a 60ASA to give you the exposure you need. you can:

a: get a bigger light (like a 5K if you're going tungsten)
b: get rid of the adaptor
c: come up on the gain
e: get rid of the adaptor AND come up on the gain

as for the cookie you can use a 4' x 4' empty frame and place either 1" or 2" black gaffers tape horizonatlly untill you get your desired look.

a PAR 64 could help. experiment with both a narrow and a medium lens. that will be very punchy and will get you closer to your stop. there's no need to "focus" it. just get the center of the beam on the subject's face.


Thanks for the help; since this is in my garage sans generator I can't go much above a 1k (tempted to rent a 1.2k hmi but it's not worth it for two brief shots) but I'll keep an eye out for a diachroic par64 and set something up like you've suggested. I may just limit myself to my 50mm f1.4 for the master and 85mm f1.8 for the close up (where I can move lights in...) but unfortunately gain and removing the adapter are out of the question.

Anyhow, thanks again. I really appreciate the advice.
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#6 Ralph Keyser

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Posted 23 April 2007 - 11:25 AM

Matthew,

Frank has already added some excellent comments.
You haven't mentioned the size of the space you are working with, which might be helpful.
Is it vital for you to light to daylight color temp? I don't know what other light sources are in use, but as you know, CTB soaks up a lot of light, and going to tungsten temps would eliminate that issue.

For power limited situations, it's really hard to beat HMIs. Are there other scenes you could pull up to make the rental of an HMI make sense?

A narrow, or very narrow, PAR64 has a lot of punch for a 1K light, and might be helpful to you, although I think the light from them is pretty harsh. I would not spend much effort on hunting for dichroic PAR64 lamps. The dichroic glass is made by a high-tech approach that lays down very thin layers of carefully controlled metal oxides in a vacumn deposition process. The advantage is that it does not degrade over time even under very high heat, plus it is very accurate in terms of the color correction that you get from the glass. The downside is that it is a very expensive process. You won't find cheap dichroic glass, and you certainly don't want it on something disposable like a globe.
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#7 David Bradley

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Posted 23 April 2007 - 11:35 AM

you must be shooting with a severe amount of negative gain. I frankly don't see the need to lower the gain so significantly if your shooting standard video signal either NTSC or PAL. There isn't significant resolution to justify it and you probably won't reduce visible artifacts.

Come up on the gain.
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#8 M Joel W

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Posted 23 April 2007 - 12:07 PM

What about an ellipsoidal? They seem to be pretty cheap on ebay (500w-750w). Aren't these the focusable lights where you can put the cookie right in front of the light?

The 35mm adapters eat up tons of light, sadly. It really is somewhere around 100ISO, max, and I like to expose one stop over on video interiors since I can control highlights, anyway and the dvx is noisy.
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#9 Michael Nash

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Posted 23 April 2007 - 05:03 PM

Ellipsoidals are perfect for the kind of thing you want to do, although the brightness of the output will depend on how far away you place the unit. Most elliposidals create a fairly small pool (they're marked according to the degree of their spread), so pulling it back to create a large enough pattern may drop the light level too low. The patterns are on metal slides that go inside the unit, just like slides in a slide projector. You have to get the ride slide (or "gobo") with a venetian blind pattern for it to work.

Par 64's won't give you a sharp enough shadow to get that pattern. Even with wide flood globes, the beam is still fairly focused and gives you a "mushy" shadow unless you back it very far away. Spot globes make the shadow even softer.
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#10 Chris Keth

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Posted 23 April 2007 - 11:05 PM

What is the relation of the light, the cookie, and the actor? For this to work the best (sharp shadow) you want to have the cookie fairly close to the actor and the light fairly far away. If it's a fresnel fixture, you want it on full flood.
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#11 Shane Bartlett

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Posted 24 April 2007 - 06:33 AM

I recently had a similar setup--small space, using a cookie, only a few lower-wattage open-faced lights and several 1k Par 64's (but no 35 adapter). Trust me, you will need a big cookie, and you will have to get the PAR 64 pretty far away. In a small space that is a problem.

Since you mentioned that you are in your garage, is there a window you could aim it through from outside? Two-inch tape across the window-frame usually works for the venetian blind effect. And you can rig a duyvetyne tent outside to control the amount of sunlight coming through the window.
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#12 M Joel W

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Posted 25 April 2007 - 08:13 AM

What is the relation of the light, the cookie, and the actor? For this to work the best (sharp shadow) you want to have the cookie fairly close to the actor and the light fairly far away. If it's a fresnel fixture, you want it on full flood.


That's the catch-22, though. If I use full flood the light is too dim, so I need to move it closer, resulting in fuzzy shadows. If I use full spot the light is bright, but it is fuzzy so I have to move it back...resulting in it being too dim. Damn you, fresnels.

It's a medium shot and the light only has to hit the actor from the waist up, but I still may consider just not bothering with this effect. It's not integral to the story, just something that would help. The ellipsoidals seem like the best option but I don't understand how they work (are they focusable?) or where you get gobos for them, or how switching lenses effects them. I also found a 400w HID with a CRI of 91 (I know...) for $199 with an electronic ballast, and this is tempting, but it's open face so I would have very little control of the light.

Gah. Oh well, thanks for all the help. If nothing else it's been very educational (and maybe I'll pull off the shot after all, even)...

Edit: And I just discovered that dichroic par 64 bulbs are $600 and have a short life. Yikes.

Edited by Matthew Wauhkonen, 25 April 2007 - 08:15 AM.

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#13 Chris Keth

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Posted 25 April 2007 - 10:45 AM

That's the catch-22, though. If I use full flood the light is too dim, so I need to move it closer, resulting in fuzzy shadows. If I use full spot the light is bright, but it is fuzzy so I have to move it back...resulting in it being too dim. Damn you, fresnels.

It's a medium shot and the light only has to hit the actor from the waist up, but I still may consider just not bothering with this effect. It's not integral to the story, just something that would help. The ellipsoidals seem like the best option but I don't understand how they work (are they focusable?) or where you get gobos for them, or how switching lenses effects them. I also found a 400w HID with a CRI of 91 (I know...) for $199 with an electronic ballast, and this is tempting, but it's open face so I would have very little control of the light.

Gah. Oh well, thanks for all the help. If nothing else it's been very educational (and maybe I'll pull off the shot after all, even)...

Edit: And I just discovered that dichroic par 64 bulbs are $600 and have a short life. Yikes.


Have you tried removing the lens from the fresnel (resulting in an "open eye" fresnel, some people call it)? The lens usually sucks about a stop, more if the lens is dusty. This might help you get the hard shadow you want as well as the quantity of light you need.
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Gamma Ray Digital Inc

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