LED lighting in studio: pros & cons

[Parker Day]

I'm looking for a continuous lighting set up for use in studio because I'd like to shoot video in addition to my stills and I'm intrigued by having a what you see is what you get set up. I'm deeply committed to my beloved Ektar so I'd like to find LED's that are capable of 5600K and bright enough for ISO 100, f/8.0, 1/200. Set up will primarily be a 107" wide seamless with 2 subjects.

What gear should I look at or is this just a fool's errand?

 

[Leigh B]

LEDs are highly monochromatic.

Even so-called "dayllight" emitters are really combinations of narrow-band emitters.

I suggest you examine the spectrum of the lamps to be sure they match the spectral sensitivity of the film.
This info is normally included in the manufacturer's published specifications for each lamp.

If they appear to, then live tests with the camera would be appropriate.

- Leigh

 

[photog_ed]

Modern white LEDs are broad spectrum and work like a fluorescent lamp. They are typically made by coating a blue LED with a phosphor. The LED excites the phosphor, which emits a broad spectrum centered in the yellow. White balance is achieved by mixing the blue light with the yellow. The spectrum is smooth and broad, but typically has a lump in the blue.

As Leigh says, check out the LED manufacturer's specs and do a test with your film of choice.

Ed

 

[baachitraka]

CRI??

 

[photog_ed]

CRI??

The CRI of LEDs is getting better all the time, and is an active area of R&D for lamp manufacturers. Some LEDs are tunable, allowing consumers to adjust between "warm" and "cool."

The relevance of the CRI metric for LEDs is also a subject of debate.

Ed

 

[baachitraka]

I like continuous light but settings up halogen lights at home can be costly and at times it may go hot and cause fire.

Hope, one day we will have a nice LED studio lights with good CRI(if this is any relevant).

 

[Les Sarile]

Do you have a continuous lighting set up now and if so what are they?

 

[Kawaiithulhu]

Has anyone done an objective test of "high CRI" LED lights versus other continuous lighting solutions? I mean, take three or four films and do an in-place shoot out? Ektar, Portra, Velvia, etc...

My guess is that color differences between emulsions is going to have way more of an effect than switching between different lighting systems.

 

[M Carter]

I've shot film professionally and full-time since the early 90's. I got a Panasonic DVX when desktop video hit, and now do mostly corporate video with a big Panasonic camera and (really, primarily) the Samsung NX1, which shoots wicked 4K. My video-niche is "looks like you had a big crew, but done using sort of guerilla-indie filmmaking techniques", IE I own my gear and don't rent and do most audio, video and lighting myself. And my stuff looks very tight, not like kid-with-a-DSLR (all this to let you know where I'm coming from).

LEDs have come a LONG way. The current Aputure stuff renders very well, usually I find it needs like 1/8 green to match my daylight stuff.

But for LEDs with decent power, you have to spend a lot of money. I have a 575 HMI par for fighting daylight in window-offices, a 400 HID setup for softboxes and general use, a couple HID 150 fresnels, but in most cases I try to use my biax fluorescents - Kino-knockoffs. they're cool, bright, no hot-restart issues, small and affordable. My Aputure (672) is used as a kicker, hair/cheekbones, or for a background wash.

I don't use Kino tru-match tubes, and I've found my lamps need 1/4 CTB and 1/8 minus-green to render excellent 5500k. Often I manually white balance through a mild cooling filter (like a 1/4 CTB) to warm things up a hair. (I test all my daylight stuff by shooting tests with a raw DSLR, looking at the temp and tint sliders it takes to get good daylight, use that as a guide for gels, shoot again and dial it in). I don't shoot film for motion work, but for digital sensors, this approach works perfectly and my fixtures are marked with gel combos needed.

So as far as CRI - to me it's fairly meaningless when you get over 85 and seems like something the inexperienced (or wealthy!) fight about. If the light can be gelled to render well (without killing many lumens), it's fine with me - considering a 4-tube biax is under $200, pulls 220 watts, packs reasonably small and light, is reasonably cool, and puts out about 1k tungsten equivalent (more like 1600 watts if you compare to a tungsten fixture with full CTB - CTB is a light-eater). Kino trumatch tubes are about $28, so add $100+ to a quad biax - I think they render a bit too magenta, and they lose about 20% brightness over a standard film-industry intended tube.

If I location scout and I need my lights to match existing office lighting (current flo tubes and bulbs are fairly consistent at around 3700k with a big hit of green), I shoot raw stills at the location and dial in my gels so the flo's and HMIs match the office lighting - usually some +green and CTO. Then I manually balance at the location. Again, skin tones come out natural, everything's good.

All this to say - for a budget, try some biax fixtures, widely available in duals and quads (and the occasional 6-tube unit). If you need a hard light, the budget answer is a 1k fresnel, some CTB gel and a couple scrims (or some metal windowscreen in a gel frame). Often you want a hard light for non-key uses, and using 1/2 CTB can look really nice and keep the lumens up. A dimmer will warm the light, so often you need a few flavors of CTB to dial it in.

Frame grabs of biax shoots:

 

[Parker Day]

Do you have a continuous lighting set up now and if so what are they?

I do not. I've been stuck on strobes.

 

[Parker Day]

I've shot film professionally and full-time since the early 90's. I got a Panasonic DVX when desktop video hit, and now do mostly corporate video with a big Panasonic camera and (really, primarily) the Samsung NX1, which shoots wicked 4K. My video-niche is "looks like you had a big crew, but done using sort of guerilla-indie filmmaking techniques", IE I own my gear and don't rent and do most audio, video and lighting myself. And my stuff looks very tight, not like kid-with-a-DSLR (all this to let you know where I'm coming from).

LEDs have come a LONG way. The current Aputure stuff renders very well, usually I find it needs like 1/8 green to match my daylight stuff.

But for LEDs with decent power, you have to spend a lot of money. I have a 575 HMI par for fighting daylight in window-offices, a 400 HID setup for softboxes and general use, a couple HID 150 fresnels, but in most cases I try to use my biax fluorescents - Kino-knockoffs. they're cool, bright, no hot-restart issues, small and affordable. My Aputure (672) is used as a kicker, hair/cheekbones, or for a background wash.

I don't use Kino tru-match tubes, and I've found my lamps need 1/4 CTB and 1/8 minus-green to render excellent 5500k. Often I manually white balance through a mild cooling filter (like a 1/4 CTB) to warm things up a hair. (I test all my daylight stuff by shooting tests with a raw DSLR, looking at the temp and tint sliders it takes to get good daylight, use that as a guide for gels, shoot again and dial it in). I don't shoot film for motion work, but for digital sensors, this approach works perfectly and my fixtures are marked with gel combos needed.

So as far as CRI - to me it's fairly meaningless when you get over 85 and seems like something the inexperienced (or wealthy!) fight about. If the light can be gelled to render well (without killing many lumens), it's fine with me - considering a 4-tube biax is under $200, pulls 220 watts, packs reasonably small and light, is reasonably cool, and puts out about 1k tungsten equivalent (more like 1600 watts if you compare to a tungsten fixture with full CTB - CTB is a light-eater). Kino trumatch tubes are about $28, so add $100+ to a quad biax - I think they render a bit too magenta, and they lose about 20% brightness over a standard film-industry intended tube.

If I location scout and I need my lights to match existing office lighting (current flo tubes and bulbs are fairly consistent at around 3700k with a big hit of green), I shoot raw stills at the location and dial in my gels so the flo's and HMIs match the office lighting - usually some +green and CTO. Then I manually balance at the location. Again, skin tones come out natural, everything's good.

All this to say - for a budget, try some biax fixtures, widely available in duals and quads (and the occasional 6-tube unit). If you need a hard light, the budget answer is a 1k fresnel, some CTB gel and a couple scrims (or some metal windowscreen in a gel frame). Often you want a hard light for non-key uses, and using 1/2 CTB can look really nice and keep the lumens up. A dimmer will warm the light, so often you need a few flavors of CTB to dial it in.

Frame grabs of biax shoots:

View attachment 166175 View attachment 166176

Thanks for your input. I'm leaning toward 1k fresnels with CTB gels. I think that'll hit the sweet spot of not being too expensive, being bright enough, and having workable color temperature. I dream of ultra high quality LED lights like the Arri Sky Panel but at around $5k each, I'm not quite ready for a set of them.

 

[Chan Tran]

I don't know but perhaps some companies have already done this. Making a very powerful LED. So powerful that it could overheat and if operated on batteries it would drain the batteries quick. However it would be connected to a special sync circuit from the camera. It's not normal X sync since the light should be on before the shutter open and only off after the shutter is close. The duration while much longer than that of the flash (1/125 or 1/60 of a second) but much shorter than a continuous light.

 

[M Carter]

Thanks for your input. I'm leaning toward 1k fresnels with CTB gels. I think that'll hit the sweet spot of not being too expensive, being bright enough, and having workable color temperature. I dream of ultra high quality LED lights like the Arri Sky Panel but at around $5k each, I'm not quite ready for a set of them.

Keep in mind a 1K fresnel with full CTB is about a 300w equivalent - kind of gets you into 400 speed film range. But 1ks are cheap, either used from eBay (usually theatrical but useable), the Chinese Arri knockoffs (people used to report ground problems and checking the wiring, but I think they've improved their QC over time) or used or new Arri or Mole fixtures. They're handy though, nice hard-ish light, or shoot them through diffusion. If you're going to diffuse a lot though, get an open-faced unit, fresnels are really inefficient. There are theatrical-style rectangular open-faced lights with yokes and barn doors (sometimes call cyc lights, or nook lights) that take the "shop-light" style bulbs, which are available from 100w to at least 750 - the globes are really cheap, and fast to swap out.

We're seeing more power from LED panels every year in the $1k range - still a lot for one fixture though.

But if you want soft daylight, for now the biax stuff is very heard to beat, and almost no-brainer at under $200 for a quad.

 

[btaylor]

The lack of availability of tungsten balanced still camera films makes it harder to use the great halogen fixtures of the past. I like their look. LEDs can certainly provide you with the quality of light you need, but good ones cost a bundle-- they are the latest thing in continuous lighting, like the Kinos before them. The biax units are a good compromise of cost/benefit in a daylight fixture.

 

[AgX]

The CRI of LEDs is getting better all the time, and is an active area of R&D for lamp manufacturers.

Here is a video that shows what is possible by now. Of course that does not mean you will get it with any LED light on the market:

http://www.arri.com/de/lighting/l_serie/videos/
(watch 2nd video)

 

[mdarnton]

Take this with a huge grain of salt because I haven't tested this idea: recently we moved our business into a new location. My partner was intensely interested in getting accurate lighting because our stuff (antique violins) looks best in good light and we'd had bad experiences in the past. He finally found LED spotlights for track lighting, and our new shop has a hundred or so of these things. When the first sample came in, I mounted it in an old photo reflector just to see what it would do. It put out between what a 250 and 500W blue photoflood would do and the color wasn't bad. The bulbs are spec'd to equal around 90 watts of incandescent and cost only about $20 each, but they were very obviously much brighter than that (probably because of the concentrating reflector).

I was pretty impressed. When I get my studio back (it's currently under construction in the new location) I'm going to try these out to see what they can do. I had previously been looking at LED video banks and was put off not only by the price but also by the diffuse light spread they offer (without the advantage of large size of something like a softbox) but something like this that might more closely mimic hot lights, and that I can handle. I won't be reporting on color, because everything I would do with them is large format black and white, but at this point they're VERY interesting to me! I'm mainly commenting on them because the flood light format seems to be a good way to tap the LED wave without what I perceive as the disadvantages of panel lights, and bonus points if the color turns out good---then I might use them for the violins, too (right now I use strobes).

In previous back workshop shop versions I have used Verilux fluorescents after being tipped off to them over 30 years ago by a industrial film maker friend, and they were great for retouching. I don't have enough hours under the new LEDs to see how they stack up for color matching in my work.

 

[AgX]

When the first sample came in, I mounted it in an old photo reflector just to see what it would do. It put out between what a 250 and 500W blue photoflood would do and the color wasn't bad. The bulbs are spec'd to equal around 90 watts of incandescent.

This is contradictory.

 

[mdarnton]

That's why I finished the sentence the way I did. As for the apparent contradiction, talk to the maker, I suppose. All I can tell you is that they put out a lot more light than the rating would suggest.

 

[AgX]

I did not realize that reflector thing. If that 90W incandescant had an angle much smaller than of a photoflood.

 

[mdarnton]

Dead Link Removed
This is the bulb that I was messing with. I am going to get a couple to try, and see how they do.

 

[baachitraka]

Dead Link Removed
This is the bulb that I was messing with. I am going to get a couple to try, and see how they do.

Seems not so bad light. At-least for B+W four bulbs will do a good job at a distance 1m from the subject.