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Author Topic: Continuous Lighting... an Introduction?  (Read 10990 times)
jsch
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« Reply #20 on: April 29, 2012, 11:04:13 AM »
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Help me understand this a little better, please... Tungsten are what we formerly know as light bulbs, right? Except these would be more bright and consistent in their light color. What is HMI? Is it Halogen?

Help me understand this a little better, please... Tungsten are what we formerly know as light bulbs, right? Except these would be more bright and consistent in their light color. What is HMI? Is it Halogen?

Tungsten is in German "Wolfram" but the word in film industrie is used for lightbulbs which contain a halogen to prevent a blackening of the glas where the tungsten filament sits in, used in: http://www.arri.com/lighting/lighting_emea/tungsten_lampheads/arri_fresnel/arri_650_plus.html

HMI is Hydrargyrum medium-arc iodide, this is a burning arc, to get white light you have to add different elements to the arc, used in:  http://www.bron-kobold.com/kobold-broadcast/products/daylight-hmi-sets/?tx_bronproducts_pi1[product]=571&tx_bronproducts_pi1[action]=showproduct&tx_bronproducts_pi1[controller]=Products
or
http://www.arri.com/lighting/lighting_emea/daylight_lampheads/arri_fresnel/arri_true_blue_d5.html

Are you located in Berlin? You can/try rent everything for example at http://www.delight-rent.com/frameset.jsp?lang=en

Usually people talk about continuos light for film and distinguish between daylight (5500 Kelvin, either HMI or tungsten with a filter/gel) or tungsten (3200 Kelvin).

Hope that helps.

Best,
Johannes
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Yoram from Berlin
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« Reply #21 on: April 29, 2012, 01:07:29 PM »
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Interesting, thanks. Yes, Delight is a great rental house. No idea what they put in the coffee there, but they are ALWAYS in a good mood, and super helpful.
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jsch
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« Reply #22 on: April 29, 2012, 02:41:00 PM »
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I spent the afternoon in my studio to prepare some shots for the next week. I did some short tests with flash and tungsten because I was curious. I used 3 different fresnel spots: ARRI 650 Plus (Tungsten), Broncolor Pulso 4 Spot (3200 Ws / 650 W modeling light tungsten), Bläsing Spot (basically a ARRI T1 with a built in flash 2000 Ws and a 650 W mod. light). They all focus from around 15-50°.

I set the light meter to 100 ASA and 1/60 of a second. I set all fresnels to Spot setting (~15°):

ARRI 650 W –> f-stop 4
Broncolor Pulso 4 Spot (650 W mod. light) –> f-stop 2
Broncolor Pulso 4 Spot (3200 Ws flash) –> f-stop 32.7
Bläsing Spot (650 W mod. light) –> f-stop 2
Bläsing Spot (2000 Ws flash) –> f-stop 22.5

This is why photographers usually use flash: If you only compare the Broncolor with the ARRI. The lights are very similar. The flash easily gives you around 128 times more light (with a shutter speed of 1/60). And with an Grafit A4 generator you can adjust the f-stop between 32.7 and 5.6 in a few seconds with your fingertip. Try this with continuous light. On the other side you have a tungsten light. 650 W give you f-stop of 4 (2k perhaps 5.6, 5k perhaps 8). You can use a scrim to reduce the light further down. But if you set the shutter to 1/125 you lose one stop more with continuous light, but with flash nothing changes.

On the other hand TMARK is completely right: Best for portraits is tungsten (and in my opinion natural light) and large format film.

Hope that helps.
Best,
Johannes
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Chris_Brown
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« Reply #23 on: April 29, 2012, 05:41:22 PM »
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In addition to others' suggestions, I would also try Kino Flo products. While their main use is in cine photography, they are another great lighting tool for the still shooter.

They are light, draw very little power, quick to set up and offer both 5000K and 3200K color temp bulbs.
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~ CB
fredjeang
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« Reply #24 on: April 29, 2012, 06:33:41 PM »
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Also, there is an aditional chalenge at the moment you work in multicam config.

If you work on location (by oposition to the studio), you'd need to light the external window(s) in the day (not always possible), specially in unstable weather (clouds like cumulus are a mess because their effect is brutal, sudden shade, sudden bright) so the artificial lightning always commands.
But when multicams are involved you'll have different frame angles of the same scene. It's one of the most difficult situation for a DP. I'm learning this at the moment and it's complicated. The help of the old foxes from the cine crew is priceless if you can access it.

Technical equipment and gear is easy to learn, but the use of CL requires a lot of practise and learning from mistakes. You need to burn watts.(and warm this planet a little bit more. We're freezing in Madrid)
Something that works fine in an axis, doesn't in another. It's not rare to make mistakes on set and end with 1 or 2 stops differences and the consequences can be that it looks from another scene-moment. I'm actually correcting frames of a multicam sequence that has this issue on some footage and it's time consuming. My patience being close to the absolute zero with those kind of problems.

On the tungsten side (3200), you can control the intensity and therefore the temp. Tunsten has the same color rendition indice than the sun: 99 and those lamps stay stable during all their lifetime (not the HMIs).

The HMIs (5600) have more power BUT...the color rendition is worse than the tungten and lifetime of lamps is shorter. When the lamps are getting old, they loose their color temp and the spectral is not continuous like tungsten but like a wave. (no mess with shutter speed and keep an eye on the lifetime's lamp)

To light the subject(s), you need to keep in mind the Lambert law (try to find some infos in your lenguage because I can't explain it with my limited english). So you know that the distance and the power require is not the same. As you'd imagine, it's a square law.

I've noticed that the 8bits are crap with tunsten. The impact is more pronunced than with other sources. So if you plan to shoot in CL motion with those dslrs, you'll have more possibilities to get banding (very nice indeed!...). The way you expose is critical, very specially with those still cameras. You need to be (in digital!) on the very limit of blowing highlights, just below and the flatter you shoot the best (IMO, not everybody needs it) and watch particularly the histogram because there is no reliable monitoring.

Our isos settings are generally from 4-500 isos to 800-1250 and quite open. 800 is a sort of standart for me. As the need for elec power is critical with the increment of distance, you need to have flexibility if budgets are tights.

Best regards from freezing winter 2 in Madrid.
« Last Edit: April 29, 2012, 07:27:55 PM by fredjeang » Logged
K.C.
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« Reply #25 on: April 30, 2012, 01:08:14 AM »
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I did some short tests with flash and tungsten because I was curious. I used 3 different fresnel spots...

By testing with Fresnels at 15 degrees you're testing at close to the maximum efficiency for these lights. Put a scrim, silk or softbox in front of them, or change them to a wider beam spread and their efficiency drops dramatically.

You are quite right, this is why most photographers use flash. Continuous light from any source is far less efficient all while drawing immense amounts of electrical current and producing overwhelming heat in a closed space like a studio.

Cinematographers sweet spot to shoot at is typically F/4 ~ F/5.6 for a very practical reason well beyond the trademark shallow depth of field look.

Try hot lights. You'll understand how much control  and efficiency your Profoto heads and modifiers are giving you.

I've used both for a couple of decades. I'm speaking from experience.



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K.C.
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« Reply #26 on: April 30, 2012, 01:10:13 AM »
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In addition to others' suggestions, I would also try Kino Flo products. While their main use is in cine photography, they are another great lighting tool for the still shooter.

They are light, draw very little power, quick to set up and offer both 5000K and 3200K color temp bulbs.

For broad fill light, yes, they're nice. But have you looked at the OPs images ? Much of the lighting he's doing can't be done with a Kino.
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Yoram from Berlin
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« Reply #27 on: April 30, 2012, 01:18:13 AM »
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Thank you everyone, as usual I can rely on this community to be generous in sharing mind-bending amounts of experience.

Lot's to chew on... ISO needs to be seen, every camera has a different native ISO... Canon seems to be calibrated to 100, whereas the PhaseOne backs are at 25... I don't mind going a little shallower, though shooting at f11 has been a nice safety buffer that I will need to leave behind.
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jsch
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« Reply #28 on: April 30, 2012, 05:05:37 AM »
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By testing with Fresnels at 15 degrees you're testing at close to the maximum efficiency for these lights. Put a scrim, silk or softbox in front of them, or change them to a wider beam spread and their efficiency drops dramatically.
...
Cinematographers sweet spot to shoot at is typically F/4 ~ F/5.6 for a very practical reason well beyond the trademark shallow depth of field look.

Try hot lights. You'll understand how much control  and efficiency your Profoto heads and modifiers are giving you.
...

You are absolutely right. I just wanted to help Iron Flatline with some numbers. I'm more at home in the Broncolor world than in the Profoto universe. But I guess they are very similar.

In terms of efficiency I guess the Briese systems are worth to consider. You can get them in flash, tungsten and HMI versions. Efficient but expensive. And I you want to get a feeling for it, you can rent the light former and the different fixtures, which are easily interchangeable.

Best,
Johannes
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TMARK
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« Reply #29 on: April 30, 2012, 08:32:37 AM »
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In reply to:  "Thank you everyone, as usual I can rely on this community to be generous in sharing mind-bending amounts of experience.

Lot's to chew on... ISO needs to be seen, every camera has a different native ISO... Canon seems to be calibrated to 100, whereas the PhaseOne backs are at 25... I don't mind going a little shallower, though shooting at f11 has been a nice safety buffer that I will need to leave behind."

This is one reason I stopped using MFDB.  When I was shooting stills and commercials on the same set, I needed strobes to use the backs.  ISO 400 was pushing it for that generation of Phase One back (P30+), so strobes were the answer, but then the stills didn't match the motion, at all.  The look was just too different, so I used DSLRs, which worked well at 800 iso, and produced useable images.  Then the D3x, which was really in a different league, but I digress.  I don't know what the current generation of backs can do, I haven't used anything newer than a P30+.

And Fred, about the multi-cam/multi angles and lighting:  its tough, especially now that crews and budgets are smaller. 
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billy
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« Reply #30 on: April 30, 2012, 12:36:59 PM »
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That being said, I like continious, I like how digital reads 3200k as a white point, makes things look nice, puts a heen on skin rather than penetrating it like 5600k sources.


Off topic but could you explain this comment a bit more? How you literally set your color balance ( white eyedrop tool on a white card in the scene? ).
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TMARK
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« Reply #31 on: April 30, 2012, 02:47:52 PM »
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Off topic but could you explain this comment a bit more? How you literally set your color balance ( white eyedrop tool on a white card in the scene? ).

Sure.  I use a Macbeth chart, balance off the medium gray chip, shooting tethered.  That is the starting point.  The rest is done in post.  Arri fresnels have a a very good color rendering.  I use a Minolta color meter as well, because I'm often working with film and need to gel lights/windows, see if I need to kill the practicals in the room because the insane variation in household and indutrial lighting requires much work.  I usually end up replacing all flourescents with Kino floursescents, because the standard tubes produce the oddest colors which are very difficult to get rid of, even in post.  My mantra is "In Camera, In Camera, In Camera".   Too much post time kills the joy of photography.

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fredjeang
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« Reply #32 on: May 01, 2012, 02:59:18 PM »
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My mantra is "In Camera, In Camera, In Camera".   Too much post time kills the joy of photography.

This is so true !

The less time in post, the healphiest happiest and longuest life.
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kirktuck
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« Reply #33 on: May 06, 2012, 03:44:26 PM »
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I think you've barely tapped the surface of LEDs if you think they are all small, battery powered units.  There are a number of companies making very powerful LED light panels and harder fixtures for the movie industry.  You can start with LitePanels, go to Nila and Altman and scores of other sources.  The big, A/C powered panels and the spots from Altman and Arri are very good.  They are also being widely integrated into theater lighting.  LED technology is definitely NOT stuck where is was when most people looked at the LitePanel minis five or six years ago....

Also direct your attention to some of the tri-color panels made by a number of manufacturer that allow you to change color balance and color temperature.

You'll never be able to match the sheer power of instantaneous flash.  You have to think cinematically.  But it's very, very do-able.

My book is a decent/recent source of general info about what's out there.  But a trip to a local cinema supplier should quickly educate you about how much more stout the selection of LED light units is now...

You might also look into a new light source: Plasma.
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kirktuck
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« Reply #34 on: May 07, 2012, 02:42:59 PM »
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There are now powerful units from Arri,  Dedolight-Felloni, Mole Richardson (big, fat, powerful LED fixtures staring around $4,000 USD), and Zylight.  Check them out on B&H's website or on their individual websites.  LED grew up while you weren't looking.  Lips sealed
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Peter McLennan
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« Reply #35 on: May 07, 2012, 03:30:10 PM »
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LED grew up while you weren't looking.  Lips sealed

How does their CRI compare with, say HMI?  Or tungsten halogen?

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kirktuck
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« Reply #36 on: May 11, 2012, 01:39:43 PM »
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The new panels from Lowel, called "Primes" are rated at 91 CRI.  That's damn good.  A little, tiny bit of specific filtration and you have a beautiful light source.  I didn't mention the Lowels when I responded above but I spoke with their product manager this week and the Primes are very well done.  Not too expensive and very workable.  Evaluating their 200 and 400 panels with an eye to including them in the studio inventory.  91 CRI in a raw file = really, really good.
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Fine_Art
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« Reply #37 on: May 12, 2012, 02:46:43 AM »
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Sure.  I use a Macbeth chart, balance off the medium gray chip, shooting tethered.  That is the starting point.  The rest is done in post.  Arri fresnels have a a very good color rendering.  I use a Minolta color meter as well, because I'm often working with film and need to gel lights/windows, see if I need to kill the practicals in the room because the insane variation in household and indutrial lighting requires much work.  I usually end up replacing all flourescents with Kino floursescents, because the standard tubes produce the oddest colors which are very difficult to get rid of, even in post.  My mantra is "In Camera, In Camera, In Camera".   Too much post time kills the joy of photography.



If you want cheap reliable 5000k at 92 CRI go with 4ft Chroma 50 tubes. 3 $20 shop light fixtures with 6 $10 bulbs in a doubled layer soft box will give you massive lumens for low ISO studio work. I use those constantly. They don't get hot. They don't waste a lot of energy. They run forever.

The only thing better I've used was a small 96 CRI arc-lamp. I originally got this for a HD LCD projector project. It became redundant when 1080p TVs provided more resolution than my small SXGA LCD. The one advantage of that for lighting was the highly directional arc-spot gave huge control of the look of shadows. You can make the same directional light you use at sunrise naturally but in 4200k. Just lifting a white projector screen to bounce off you could make it as hard or soft as you like.
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