LED Photo lights?

[bretti_kivi]

I'm not sure where it should be, so I'll put it here...

Has anyone tried / made LED photo lights? Whether flash or permanent, I'd be interested to hear what your experiences are...

Bret

 

[The_LED_Museum]

The only LED-based photo light I've had any experience with is this one - although it's marketed as a "video light", I don't see why it can't also be used as a still photograph light.
It comes with two orange filters (that can be used seperately or in tandem) to lower the color temperature.

 

[SemiMan]

In terms of wattage, photo-strobes are orders of magnitude brighter. There are some color issues with LEDs.... do a search, lots of discussion.

Semiman

 

[jeffosborne]

Hi bretti kivi - I have been making lights to use with my still camera, using Luxeon Rebel neutral-white LEDS. This one was built with a Pac-tec enclosure that came with a sturdy belt-clip, is fan-cooled and has a high-low switch for 350 or 800ma. On high it is about 900 lumens:

Color rendition has been a small problem, and I had to add a diffuser so it is not so bright to look at, when photographing people. The diffuser cuts down the light by about 25%.
Are you considering building or purchasing LED lights for photography?
Cheers,
Jeff O.

 

[Illum]

not sure if using an existing light count

My camera is a Canon Powershot SD630, its more than a point and shoot...but not anywhere near the rebels.

Surefire L4 with a creamy white tint
the color rendition is great, but the light is very very harsh if the photos are taking towards the evening or a very dark room indoors.

oddly enough I use it to remove shadowy faces, or to accent something in the foreground, such as a object or something your audience [whoever your shooting at] may be holding. I use it anywhere from taking natural insect photos to night time group pictures

17670s are great when your using it frequently. LuxV eats cells like my Venus fly traps exhausting the tiny mosquito farm

heres some shots I've taken last time when I visited Shenandoah Nat. Park. SC using the L4 while in the field.
digital macro is simply awesome

in the grass field when I was looking for spiders in the wildflower patch, the L4 wasn't as obvious as the others


the cocoon I spotted after taking family picture underneath a trail sign, its only 3/4" in length


Found this harvestman after investigating a possible carpenter bee hive


My sole remaining L4 is in the hands of AaronM to get MC-E'd, hopefully that should improve certain limitations

 

[blasterman]

the color rendition is great,

Uh....I really think you guys should stick to the high CRI Seoul chips for this.

 

[snarfer]

Uh....I really think you guys should stick to the high CRI Seoul chips for this.

The high CRI Seoul chips seem pretty limited, with color temps only 3000 and 4000. There are other manufacturers, maybe not so popular for flashlights, such as Nichia and Edison Opto, who offer a much wider range of color temperatures and form factors in high CRI.

 

[bretti_kivi]

well...

I was interested in building. For "studio" (i.e. lightbox) work, maybe some outdoors stuff. Colour temp is not really an issue, I think, as I work with RAW anyway.

Jeff, that looks pretty interesting. I'll have to take a closer look into some of the ideas later.....

thanks

Bret

 

[snarfer]

Colour temp is not really an issue, I think, as I work with RAW anyway.

Generally you will end up with a grainier result if you color balance to a lower color temperature. Most of the noise is on the blue channel, so it pays to light the blue channel more. Of course this varies depending on the camera you're shooting with. This effect is very pronounced with certain high end digital capture systems, such as Red.

Also of course color temperature becomes an issue when you are trying to match another light source in the same scene, for example the sun.

I think one of the great things about LED lighting for photography is the possibility of additive color instead of gels. Really even the most expensive professional LED lighting systems available today have barely scratched the surface of what is possible.

 

[bretti_kivi]

I shoot with a K10D. I was thinking about balancing correctly using a known grey card anyway; this is intended for use under controlled conditions to replace flash.

I was thinking ATM about using 3 x 3 Rebel stars; that should give around 300 Lumens per star. What I don't know is just how much light the normal flash would give - I use a Sigma EF-500.
I've already understood the perils of mixing light source colours; I have a couple of shots which would be great, apart from the halogen / flash mix which results in a colour change across the pic that is really difficult to get rid of.
Tell me more - what exactly do you mean with additive? Should I be adding red / orange? Any links I should be looking at? I haven't really researched, I was thinking about it first....

thanks!


Bret

 

[Illum]

Uh....I really think you guys should stick to the high CRI Seoul chips for this.

the thing is...these high CRI chips we discuss here, or respectively Nichia 083s...there isn't much info out there regarding their whereabouts or how to order them...the only place I know is through McGizmo at very limited quantities:candle:

color rendition sometimes can be compensated by the camera...either that or stick to xenon lamps with diffusers

 

[bretti_kivi]

... we're talking a little at cross purposes here, I think.
I use a DSLR in a semi-pro manner and understand how to compensate for all sorts of stuff in my pics. I'm not a professional. I am aiming to take on paid-for photo gigs this summer.
I am, however, looking for a substitute for Xenon / Flash / whatever, that is small and doesn't break the bank.

One site I use a lot for inspiration is diyphotography.net, another is the strobist blog. The first site is focussed on cheap, effective photo helpers and the second on using light creatively; I want to combine the two.

My photography (or at least some of the better pics) can be seen here: http://www.23hq.com/bretti_kivi/album/2781046 - I'd like to expand my range and for that I'll need a softbox or two.

I should have been more accurate from the start....

Bret

 

[SemiMan]

For cost, hard to compete with xenon strobes for stills. They are very efficient and very very bright for what you pay for them. The only ill is the lack of distributed light, but that is what light boxes, umbrellas and reflectors are for. The advantage of having sooooo much light is that you can diffuse things significantly without worrying about having enough light.

It does come down to whether you are shooting still objects, or moving objects. People, in almost all circumstances, would be considered moving objects, even for portrait photography. For portrait photography, you are often shooting F8+ in order to control depth of field. Combine that with wanting to be at ISO100-200, even with a good SLR, and a reasonable shutter speed, say 1/125s, and you are beyond what LEDs can do in most cases (especially when you look at perfect diffusion).

That is the simple case of light output. Now, lets talk about spectrum and color mapping. The issue with low CRI LEDS is that the camera color mapping algorithm does not understand "blue with a yellow phosphor". For the most part, it assumes that you have a source that is somewhat close to known sources, i.e. sunlight, halogen, xenon-flash, i.e. somewhat continous spectrum sources, either black-body radiators approximately, or somewhat linear like Xenon. The peaky output of a low CRI LED does not get interpreted right. Sure white will come out white since the camera will adjust for that, but the other colors will be off, and whether you work in RAW or not, you it is not a simple matter to fix that. Adode on CS4 (or is it Lightroom?) has the ability to take a reference shot to calibrate the light source. This may work. High CRI LEDs have a spectrum closer to what typical light sources have and hence you will get better results in terms of color accuracy for all colors.

What you may find lacking in LEDS is deep reds where the output tends to be comparatively low versus other sources. You may not be able to render these colors well.

Semiman

 

[blasterman]

The high CRI Seoul chips seem pretty limited, with color temps only 3000 and 4000.

I don't really care about what brand it is. The fact is, there are high CRI LEDs available that are more appropriate for this task than a typical low CRI 'flashlight caliber' LED. I also don't get why an assortment of other color temps is required, nor why it's relevant. A 4000k, 93 CRI light is about as good as gets for constant source lighting. A CRI in the 80's can be made to work if you're willing to fiddle with hue and saturation in Photoshop. It's CRIs in the 70s that really, really suck for photo/video work because you can't fix colors that don't exist.
For the sake of arguement, here's the Seoul:

http://mouser.com/Search/Refine.aspx?N=2093270+4294762567+4294719703

If you prefer the Nichia or Edison - good for you.

I am, however, looking for a substitute for Xenon / Flash

Right now, the only thing a LED based light would provide is a substitute for a ring flash for macro work, and that's only if your subject isn't moving much. Anything else would require an LED panel that costs FAR more than a 1000wps strobe rig.

Tell me more - what exactly do you mean with additive?

I believe he's referring to a LED head or panel made with RGB LEDs that can be mixed to produce any color you wish. This means, in theory, you could match the tri color LED head to your ambient lighting or other. In practice, it's more difficult than that. I have some RGB LED PARs, and my lowly warm white Crees provide better color for photo/video.
BTW - nice photo work! We have similiar styles.

and you are beyond what LEDs can do in most cases (especially when you look at perfect diffusion).

What he said.

What you may find lacking in LEDS is deep reds where the output tends to be comparatively low versus other sources

When CFLs first started getting popular I saw a lot of light panels made from 5000k bulbs, but nobody really took low CRI seriously until they found they couldn't get skin tones right no matter how much post processing they did, and they chucked the panels and went back to strobes.

Unless you need a small light that's battery efficient for macro field work, I don't see LED providing much advantage here.

 

[bretti_kivi]

that makes a lot of sense. I was thinking about a reference shot or two for the colour compensation, theoretically I can move the curves individually... I tihink I might try with the cree Q5s I have lying around and see what really happens before I invest real money into something that may well not work.

thanks - also for the compliment

Bret

 

[VidPro]

because you can't fix colors that don't exist.

Thats the one just look at the Spectrum of these things, LED Museum shows the various spectrums, i havent seen one that Has all the RGB without RGB.
in video using only these phospor coated blue leds, the best thing you can do is make a horror film

 

[snarfer]

I agree with VidPro.

With regard to additive color mixing, I was thinking that while there are a lot of products out there that use discreet LEDs for color mixing, they are pretty horrible looking when reflected. In future chip on board arrays may improve this situation.

I was talking to a film maker friend about the not-so-new Litepanels LED lights and he said "why would i want to light people with a little TV screen?"

Yes it isn't so easy to purchase High CRI LEDs other than SSC. You have to call manufacturers directly. Mostly they are happy to help.

 

[nikonf]

Hi Jeff,
This light looks awesome! I need a light like this for my still life photogaphy setups. Would you be able to build one of these for me?
I am a good photographer but I have no skill in soldering.
Many thanks,
Mike Herring
[email protected]

Hi bretti kivi - I have been making lights to use with my still camera, using Luxeon Rebel neutral-white LEDS. This one was built with a Pac-tec enclosure that came with a sturdy belt-clip, is fan-cooled and has a high-low switch for 350 or 800ma. On high it is about 900 lumens:

Color rendition has been a small problem, and I had to add a diffuser so it is not so bright to look at, when photographing people. The diffuser cuts down the light by about 25%.
Are you considering building or purchasing LED lights for photography?
Cheers,
Jeff O.

 

[jeffosborne]

Hey NikonF, thanks for the kind request, I am flattered. Nothing makes me happier than building LED lights, but I use simple hand tools, and making them one-at-a-time causes lots of hours to be spent. The cost would be more than they are worth, me thinks. I did just take receipt of 10 new 100-lumen per watt neutral white rebels, and plan to make a 9-emitter photo light with continuous dimming. It will takes weeks of fitting in a hour or two here or there to get it done. Cheers, Jeff O.

 

[bretti_kivi]

the idea of adding a red or two to that... hmmm. When I have some real time, I think I will try this.

In the mean time, it's off to mpex for some cheap manual flashes.

Bret