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Light to simulate hard sunlight


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Is there any light that can appropriately simulate sunlight? Irrespective of the distance, Is there a way with which anybody here can tell that 'this example is best suited to simulate sunlight when used through right diffusion, etc. 
In simple words - A light strong enough can create beams through windows. 
Sorry for the bad English.

(Images for ref. only)

360_F_218454108_7fIGly9pafnzUZNEq9PC5l6ApMRu0Xtx.jpg

d0f653e253e172ea32df07197b2452ad.jpg

streaming-beam-of-light-through-window-mike-m-burke.jpg

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In every picture there is fog/haze that makes the beams apparent. The use of diffusion is not expected, as it would create the soft light of a cloudy day, not hard sunlight.

If what you mean by "light strength" is "power", it does not matter for the hard/soft aspect. But low power sources will require greater aperture or raising the ISO on the camera.

However, distance does matter: the further the source, the more parallel the beams. If you put your source far far away, then you need high power sources that can be focused (like HMI frenels), to avoid loosing too much light.

Edited by Nicolas POISSON
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Thanks Nicolas. So I get it so far, I'll need HMIs to create such type of lighting, but what about the color of it? It should be gel'ed right? Also, what about the wattage system? How do I determine that 'Ahh this is the exact light that I need for this'?

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the light you needs depends on many factors. No one light will create a specific effect.

Many lights can simulate sunlight.

there are three basic qualities of a light

intensity

softness or hardness

Color

For example on a studio set you might be able to effectively imitate the sun with a 2000W tungsten light even though it is much warmer and no where near as bright as the sun, But if you are outside and need to replicate sunlight you might need something as bright if not brighter then an 18000W HMI. It just depends on the situation, knowing what light to use when is part of the basics of cinematography. Maybe look into some books or basic online classes.

 

Edited by Albion Hockney
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11 hours ago, Nicolas POISSON said:

However, distance does matter: the further the source, the more parallel the beams. If you put your source far far away, then you need high power sources that can be focused (like HMI frenels), to avoid loosing too much light.

Actually, focussing a fresnel into it's tighter "spot" beam, makes the shadow cuts LESS sharp. You get more lumens, but shadows become softer.

Full flood is where you get the sharpest cuts.

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What makes a light look like hard sunlight (no diffusion is needed) are the parallel rays of sharp light and its intensity. Ideally, like the real sun, a bright light very far away is the best approach (HMI versus tungsten is more about color temperature issues.) But obviously not everyone can afford a condor with an 18K Arrimax on it far above a window (and real sunlight would still be brighter.)

The other issue is how much area does the light have to cover, it’s a lot easier with smaller windows to fill them evenly from corner to corner. Sometimes you just have to live with only covering part of the window by imagining that your “sun” is partially blocked or broken up by objects outside the window.

If you don’t have the distance then projector-type lamps like Lekos, Molebeams, Xenon’s, and theatrical moving lights can project light with more parallel rays, just that most of them don’t have a large enough beam circle to fill a large window. I’ve sometimes taken three or four Source-4 Lekos with narrow lenses and aimed them through one window to create overlapping beams that are parallel - it feels like one sunbeam that is passing through some obstruction like tree limbs breaking it into multiple rays.

The intensity matters more if you are trying to balance the brightness of your fake sunlight with existing natural daylight because the real sun is much brighter than ambient skylight. On stage where you are creating the skylight ambience as well, it is easiest to get the balance right with your sunlight effect.

 

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19 hours ago, Sairaj Batale said:

but what about the color of it? It should be gel'ed right?

the colour depends on the source, but also on your white balance settings. If your sources all have the same colour temperature, there is no reason to gel them (I mean CTO/CTB, not ND) : you would loose a bunch of light, whereas setting your WB correctly would render the same without gels.

You would think about gels if you want to match sources of different colour temperatures (like tungsten and the sun). You may want this... or not. Search this forum, there are plenty examples of people using different colour temperatures and still creating a believable sunlight.

Edited by Nicolas POISSON
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10 hours ago, Franklin De Los Santos said:

Ok I’ll give you a straight answer instead of yapping around:

Aputure 600D should do it. If you have a money tree, One of:

Arri M18

Joker 800/1600

Dedolight PB70

 

 

 

Thanks for crunching my search numbers down to this! 

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6 hours ago, Nicolas POISSON said:

the colour depends on the source, but also on your white balance settings. If your sources all have the same colour temperature, there is no reason to gel them (I mean CTO/CTB, not ND) : you would loose a bunch of light, whereas setting your WB correctly would render the same without gels.

You would think about gels if you want to match sources of different colour temperatures (like tungsten and the sun). You may want this... or not. Search this forum, there are plenty examples of people using different colour temperatures and still creating a believable sunlight.

Thank you... Will go through this forum and look for some motivation. 

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7 hours ago, David Mullen ASC said:

What makes a light look like hard sunlight (no diffusion is needed) are the parallel rays of sharp light and its intensity. Ideally, like the real sun, a bright light very far away is the best approach (HMI versus tungsten is more about color temperature issues.) But obviously not everyone can afford a condor with an 18K Arrimax on it far above a window (and real sunlight would still be brighter.)

The other issue is how much area does the light have to cover, it’s a lot easier with smaller windows to fill them evenly from corner to corner. Sometimes you just have to live with only covering part of the window by imagining that your “sun” is partially blocked or broken up by objects outside the window.

If you don’t have the distance then projector-type lamps like Lekos, Molebeams, Xenon’s, and theatrical moving lights can project light with more parallel rays, just that most of them don’t have a large enough beam circle to fill a large window. I’ve sometimes taken three or four Source-4 Lekos with narrow lenses and aimed them through one window to create overlapping beams that are parallel - it feels like one sunbeam that is passing through some obstruction like tree limbs breaking it into multiple rays.

The intensity matters more if you are trying to balance the brightness of your fake sunlight with existing natural daylight because the real sun is much brighter than ambient skylight. On stage where you are creating the skylight ambience as well, it is easiest to get the balance right with your sunlight effect.

 

To know more about what Mullen is talking about, I recommend you read up on why the sun rays  that hit earth are parallel, once you have that, everything else is kindergarten.

here is a wiki article:

https://en.m.wikipedia.org/wiki/Hanbury_Brown_and_Twiss_effect

And here is a physics stack exchange explanation:

https://physics.stackexchange.com/questions/155075/what-makes-suns-light-travel-as-parallel-beams-towards-earth

 

 

Edited by Franklin De Los Santos
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5 hours ago, Franklin De Los Santos said:

To know more about what Mullen is talking about, I recommend you read up on why the sun rays  that hit earth are parallel, once you have that, everything else is kindergarten.

here is a wiki article:

https://en.m.wikipedia.org/wiki/Hanbury_Brown_and_Twiss_effect

And here is a physics stack exchange explanation:

https://physics.stackexchange.com/questions/155075/what-makes-suns-light-travel-as-parallel-beams-towards-earth

 

 

Thank you for the recommendation, Franklin! I'll surely check that out. Pls keep adding such informative link ?

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  • 4 weeks later...

Depending on your budget, there are different ways. For my imagefilms I often use an Apture 600D in combination with a F10 Fresnel lens and barn doors. Through a window and its perfect. For less light I use an Aputure 300D with the Aputure Spotlight (you can use it in 3 different angles and with a Gobo kit you can simulate different windows). To enhance the effect you can use additional haze.

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  • 2 weeks later...
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  • 11 months later...

 

 

On 1/31/2022 at 9:11 AM, Mark Kenfield said:

Actually, focussing a fresnel into it's tighter "spot" beam, makes the shadow cuts LESS sharp. You get more lumens, but shadows become softer.

Full flood is where you get the sharpest cuts.

 

@Mark Kenfield My intuition tells me that what you're saying is, right but I cant explain it why.

What is the technical explanation behind the change of spot to flood and the shadow cuts? 

 

Thanks!

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This is how it's explained in the Set Lighting Technician's Handbook section on fresnels:

Quote

A Fresnel creates its hardest, most delineated shadows at full flood.  The more spotted-in the fixture, the less sharp the shadow lines appear.  In full spot position, rays from the Fresnel travel more nearly parallel, but some converge slightly and cross one another.  This creates a fuzziness to any shadow cast from an object.

A fresnel lens is an approximation of a single/simple plano-convex lens, and it's a bit easier to find ray diagrams of those on the internet.  I attached a picture I found, from Firebird Optics' "Introduction to the Plano-Convex Lens" (https://www.firebirdoptics.com/blog/intro-to-the-plano-convex-lens), which shows how the light rays of a PCX lens don't converge evenly.

firebird-optics-pcx-lens-rays.jpeg

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