thoughts on LED's

[allenlennon]

hi all, i got a mate who is a eclectrical whizz. And he offered to build me some LED lights for photography. He uses them for his xmas santa photos because he is a major player in the xmas lights displays, and does it for a charity, and they seem like a great idea. He can make them as big or as small as i humainly like. And he can put in switches for diffrent brightness, as well as make rgb lights(which could come in handy).

So my question is what do you think? I personnelly think it be alright to have a variety of lights to choose. And he is lending my his lights after xmas season to see what i think, but would like all of your opinions.

Cheers

[Andrew76]

Hey Allen, just to make sure we understand your intent, you want to use the lights as props in your photos? Or as light sources to illuminate portrait subjects?

[allenlennon]

As a light source

[Manfred M]

Two main issues with LED lighting - first of all it is not terribly bright (and the same can be said for pretty well any continuous lighting) and is usually not used in still photography for that reason. If you are doing product photography and are shooting off a tripod with subject matter that doesn't move, you get away with it. If you get something bright enough to do portraiture, the LEDs have all the downsides of continuous lighting, except for the heat.

The second, and potentially more problematic issue is getting the colour temperature right. "White" LEDs tend to be anything but white and the brightest ones I've seen are heavy in the blue wavelengths. Commercial colour balanced ones (which are usually aimed at the video business) are a heavily diffused mix of different colours of LEDs to give a reasonable approximation of a fuller spectrum. If you are planning to use the LEDs to supplement other lighting, you could get yourself into trouble by having mixed light sources that will prevent you from getting your white balance (either in camera or in PP) right.

I certainly think you could have some fun with this, but need to be aware of the limitations.

[DanK]

I have been very interested in using LEDs for macro work, which I do now under halogen lighting, but so far, I have been deterred by the issue that Manfred raised. I've been waiting for reasonably priced color-balanced setups to appear.

[xpatUSA]

I have been very interested in using LEDs for macro work, which I do now under halogen lighting, but so far, I have been deterred by the issue that Manfred raised. I've been waiting for reasonably priced color-balanced setups to appear.

Disclaimer: this post is not intended to disagree with posts such as Manfred's which clearly explain the perils of mixed lighting and spiky spectra for serious work!

I use Chinese 5000K LED's at my bench, with a bit of Philips TL-950 thrown in:



I once compared LED's with Halogens experimentally in an article here. Hardly any difference, oddly enough, even though the theory disagrees. The proof of the pudding:



Nikon D50 RAW images compared (no post processing)

[Colin Southern]

Hi Allen,

Prescription without diagnosis is malpractice -- so "what kind of photography" do you need lighting for?

[Inkanyezi]

Colin is of course right, the actual usage should be paramount if any advice is to be given.

But I would like to add a bit to Ted's trial of the LED lamps, which coincides with my opinion on them, that they can be used for product photography.

In northern Europe, daylight type full spectrum LED:s are not imported by wholesalers, but we have those that resemble incandescent lamps. Here daylight types aren't sold except those very poor "twilight" types that are essentially a blue electroluminescence emitter with yellow phosphor that lack red completely. However, there are also triphosphor types that have considerably more red. The fact that there are spikes in the spectrum is indeed not a huge drawback for photography, as we use a three-colour receptor, with similar spectral characteristics to the human eye.

So basically, there are two different types of white LED, those that have a "full" spectrum (although spikey), and those that completely lack red. Most small white diodes in the market have almost no red at all. You may test them against a tail reflector for a vehicle. Holding the diode by your temple, if it has red, the reflector will shine bright red, and if it lacks red, the reflector is dead. Low colour temperature LED as those sold in Northern Europe, resembling incandescent, are stronger in the red region than most other "white" types. There is no problem adjusting white balance for such LED lamps.

Most applications with LED driven from mains modulate light with twice the mains frequency, so short shutter times should be avoided. The cycle of modulation is 1/100 second in Europe and most of Asia and 1/120 second in USA. To avoid banding, an exposure time of at least thrice that value is recommended, hence 1/30 or longer is suitable. Exposures of less than the full cycle time will inevitably cause banding.

There are also three-colour diodes, with a red, green and blue emitter, which can be adjusted to any colour temperature, but their output is very weak.

[William W]

If 'xmas santa photos' means this Kids sitting on Santa's knee - then I would not use LED lighting for that.

I would use Flash over LED lighting for any and all 'studio' portraiture; and I would use Flash as Fill or Reflectors as Fill for Outdoor Portraiture - and not LED.

My reasons are most of those listed above - but especially for Studio Portraiture: -

• there just is not enough light to generate the suitable ISO and Aperture - and if an LED can just make both of these - then it falls watt short in Shutter Speed to arrest Subject Motion.
• there is the lack of (easy) White Balance (Colour Temperature) for Batch Shooting.

WW

[Colin Southern]

I'll just come right out and say it ...

"although LEDs can be used for some types of (mainly small product) photography lighting, by and large they're a "big compromise", at best. Far better to just open ones wallet - flick out the moths - and start with even a pair of cheap studio strobes.

LED lighting for general photography is like using a tandem bike for a taxi; technically it might "do the job", but it'll be a lot of work - won't give you very satisfying results - nor will it take you very far nor anywhere very fast.

If it looks like a duck - sounds like a duck - quacks like a duck ... it's probably a duck.

[gregj1763]

Hi Allen, I asked the same question a few months ago. Read all the responses and still went and bought a couple of led lights.
Guess what, Colin is right! must be something to do with the fact he knows what he is talking about.
I tried them for portrait photography and basically they don't have enough grunt.
Ok for a little extra fill light but I still had to use flash to get decent results.
However I have used them for some macro shots and they worked well.
So listen to Colin, he is a clever bugger
Cheers, Greg

[Colin Southern]

Hi Allen, I asked the same question a few months ago. Read all the responses and still went and bought a couple of led lights.
Guess what, Colin is right! must be something to do with the fact he knows what he is talking about.
I tried them for portrait photography and basically they don't have enough grunt.
Ok for a little extra fill light but I still had to use flash to get decent results.
However I have used them for some macro shots and they worked well.
So listen to Colin, he is a clever bugger
Cheers, Greg

My neck support arrives tomorrow!

Many others always say the same thing though, especially Richard & Bill.

Honestly, it's not hard -- halogen work lights put out a lot more light than LEDs ... and halogen work lights are STILL grossly inadequate for the likes of portraiture. Not saying is can't be done ... just saying it's not "best practice" nor is it even particularly economical.

[William W]

I tried them [halogen lights] for portrait photography and basically they don't have enough grunt.
Ok for a little extra fill light but I still had to use flash to get decent results.

I still wouldn’t do that unless you are really in a controlled environment and you are meticulous with shutter speed and interrogating the images, prior to letting the Subject leave the set.

This will eventually catch one out - because to have any impact against Flash at any reasonable power setting, one is dragging the shutter for the Halogens to make an impact (or they are very, very close).

So sooner, rather than later, one WILL get a soft edge (most likely on the face) and then likely (I have seen this happen) one might spend thirty-eight hours trying to work out why the AF is just a little bit out, but only sometimes . . .
Only to end up working it out oneself or showing the image to someone who knows what Subject Movement Leading Edges, look like.

WW

[Davey]

I disagree on the brightness point these days since the newer ones do have high output but for photography I wouldn't trust them in most flavours. I use them in a lot of lighting and have cree XM-L for offraod bikelights that are VERY bright and all kinds I've wired into stuff (great for high efficiency bright lighting above the cooker etc). Problem is as mentioned they produce spikey spectra, it's essentially blue light produced directly which is filtered through yellow phosphor but there are large gaps in some parts of spectrum. Not wide enough to miss colours totally but big enough or unbalanced enough to throw subtle shades out.

I drive xm-l T6's with 3amp (3.7v always) off lithium packs and they are HID bright with a handfull of emitters and last ages off decent pack but their colour rendition index is poor. I have a neutral white single 18650 cell torch with a neutral (slightly warm) T6 in that is OKish but I prefer to use a strobe as it does throw shades out. The cold tone are really bad but the neutral and warm bins much better, but not photography standard IMO.

The one exception if your friend can find them is the warmer bin of the high CRI cree xm-l "easywhite", there are few types of xm-l and labelling gets confusing. Basically the first you usually come across T6 and the newer more efficient aka slightly brighter U2 (maybe up to U4 I haven't checked) but most are regular type with CRI of 70 to 80 and photography can do with 95 to 100 ideally. The tint is refered to as "bin" btw, info on cree's site as to what is what; it's a colour ref chart with bin numbers so easy to understand. The easywhite in warm goes to CRI 90 minimum so may be a real option in high brightness lighting, see here for specs
http://www.cree.com/led-components-a...-xml-easywhite

Thing with the easywhite warms is they are much lower brightness compared to regular warm an neutrals.

edit: the 1000lumen ratings per LED is bit of stretch if come across that and is theoretical. Real world you'll be lookign at more like 600 to 700 lumen at close to 3amp. You can get really nice highly configurable optics for LED now though so light mod anything you can imagine pretty much (I prefer ledil optics).

[Colin Southern]

I disagree on the brightness point these days since the newer ones do have high output but for photography

Would be great if someone would just take a light meter reading with them so that we can objectively see what we're dealing with.

As a "case in point though", I've just pulled up an old image that I shot a number of years ago before I really "got started" with portrait photography. If one had an average sized room illuminated by a single 200W light then that room would probably look considerably brighter than average ... for the photo I was using nothing less than FOUR 500W Tungsten work lights for a total of two THOUSAND watts. So I'm sure you can imagine how well that lights up an average room. Would LED lights be any brighter than this? No idea personally, but already the model was complaining how bright it was (and the room was starting to heat up pretty darn quick too).

Looking at the EXIF data - If I'd shot that at my usual studio settings of F11 @ ISO 100 my shutterspeed would have been down to 1/10th instead of the usual 1/125th (and even 1/125th would have been marginal at that focal length for hand-holding). Or put another way - the studio lights at just a normal power setting (1/2 power or so) are putting out TWELVE AND A HALF TIMES what 2000 watts of halogen lighting are putting out (or the equivalent of 25 THOUSAND watts in that 1/1000th of a second that they take to fire). Any LED lighting that approaches this level will cause serious eye damage.

From where I'm sitting, LEDs might have a (limited) use in a fill-light scenario, but I stand firm in my belief that for photography they'll end up costing more and producing a significantly inferior outcome for portraiture than inexpensive strobe lighting.

[rpcrowe]

IMO, studio type strobes, even the el-cheapo Chinese models (with softbox or umbrella modifiers) are better for portraiture than are continuous lights of any type.

It is simply a matter of how bright and powerful the continuous lights must be to get a decent shutter speed and f/stop. I seldom shoot at f/stops wider than f/4 since, the 70-200mm f/4L IS lens is my favorite portrait glass and the longer focal lengths at which I shoot provides quite decent selective focus. I like to shoot at ISO 160 for my studio work. I also like to hand hold my camera for portraiture.

The main advantage of the studio strobe over continuous lights are IMO:

1. they incorporate modeling lights for WYSIWYG shooting, negating the main advantage of continuous lights...
2. they are more powerful than continuous lights without the constant annoying brightness...
3. you only need to worry about the f/stop. Within the sync range, any shutter speed will work fine. I shoot at 1/60 second for my White Lightning strobes...

If you compare studio strobes with hotshoe flashes, there are even more advantages. OTOH, decent head shots can be done with a single bounced flash modified with a Joe Demb Flash Diffuser Pro. See my single hotshoe flash portraits at...
http://rpcrowe.smugmug.com/Portraits...0241&k=LXnFVZC

However, all that said, Peter Hurley, a New York City photographer, who gets $1,100 USD per head apparently shoots with continuous lights. I needed to show up for a dog rescue event (we got 3 dogs adopted so it was worth it) and wasn't able to complete viewing this YouTube video from B&H.

https://www.youtube.com/watch?v=MIMCFVlbEz8

It is a fun video to watch so I hope to complete viewing it tomorrow and would recommend it to anyone interested in photographing people. But, I don't think that I will change my shooting habits because of this video...

BTW: Peter used a large window for his head shot lightng before he began to use continuous lights. He states that this proves that the photographer, not the equipment is the important aspect in most photography. OTOH: Peter shoots his head shots with a digital Hasselblad. So much for the minimial equipment claim...

[revi]

(...)
BTW: Peter used a large window for his head shot lightng before he began to use continuous lights. He states that this proves that the photographer, not the equipment is the important aspect in most photography. OTOH: Peter shoots his head shots with a digital Hasselblad. So much for the minimial equipment claim...

I don't know, one window and one camera sounds fairly minimal to me

[Davey]

Light reading figures are available but only really good for niche stuff photo wise. I saw some testing stuff used for key lighting a few month ago but it was far from ideal yet and not really a go to for anything. Maybe in future when emitters have changed but strobes really do meet the vast majority of lighting needs and there is ZERO way LED can compete with it; certainly not used as key light at handheld shutter speeds.

The problem is when you ramp up the power they get a bit blue past a certain point and it's diminishing returns. They tend to prefer being powered just under their max rating too, I power my 3amp max T6's at 2.8a for instance. The closer to max you get the less efficient and more heat. To build something VERY high output causes issues. You can get high end of comfy viewing light level but freezing action and so on is just not option and not worth it since to compete with moderate speedlite output levels it'd take a load of emitters all at full power and thrown in with optics and cooling for such an amount means considerable price you can probably afford an Einstein by that point which is just as portable (with power pack of course), has readymade light mods and is temp and CRI perfect and can outpower LED several times over. My cheap YN560 murders my LEDs on 1/32th even and the stated GN for it is somewhat exaggerated.

There are some applications they may be suited. Night shots for instance where there is very little ambient. If you're shooting in the dark and want autofocus to work lights with "thrower" optics would work well and only continuous light would be suitable and colour temps etc don't matter since it's off in the photo. I tend to just use flashlight at desired range then lock focus, job done. Or for Troy Paiva style low light photography; I know he uses torches/flashlights in place of strobes these days so he prob uses LED since they are as bright as you'd get in compact form.

Maybe extreme range lighting too, something way out the range of a zoomed flash on full power would be lit, basically a handheld searchlight like a Nitecore TM15. You could light something pretty far away with that in low light but it'd be niche for photo work such as painting or outlining stuff on long exposure in light painted scene. A well positioned strobe closer in on a wireless trigger would work just as well if not better in most cases where the camera is too far for on camera flash to reach. Maybe for fill light or longer exposures in macro work they'd be great but still I find strobe fills that niche cheaply and is flexible light (I use assortment of modifiers from empty boxes to 2x £3 shoot through brollys).

[William W]

If 'xmas santa photos' means this Kids sitting on Santa's knee - then I would not use LED lighting for that.
I would use Flash over LED lighting for any and all 'studio' portraiture; and I would use Flash as Fill or Reflectors as Fill for Outdoor Portraiture - and not LED.
My reasons are most of those listed above - but especially for Studio Portraiture: -

• there just is not enough light to generate the suitable ISO and Aperture - and if an LED can just make both of these - then it falls watt short in Shutter Speed to arrest Subject Motion.

. . .
WW

Reply:

I disagree on the brightness point these days since the newer ones do have high output . . . etc.

I appreciate your replies.
Note that we are not discussing the brightness, but we are discussing the brightness useful enough for ‘studio portraiture’

Personally I have found that lumen (or lux) values are indicative and quite useless for calculating even ball park exposure estimates for any continuous lighting.

As you rig these lights quite often what would be more useful to your argument would be a Light Meter Reading, for example at 10 ft from your rig – which would be typical of half shot portraiture.

If, then, you are attaining exposure readings within cooee of: F/6.3 @ 1/400s @ ISO400, then (as the limit for ‘santa photos’ under continuous lighting) - you begin to have a case.

WW

[allenlennon]

sorry for the late reply, net issues and personnel issues. Thank you for your reply. And i dont think i will go with the led lights. And with continues lighting, i have a 3 light kit in continues lighting, only because it was something i could get with the budget i had. I do want strobes, but the cheapest by far(evil bay) is bout $200 for a kit, or $60 for single light only. And i can not afford strobes, even the cheap ones. And i do understand about the continues lights having your shutter speed slower, and higher iso for portraits. All my indoor shots were done with the continues lights. Although i had a slower shutter speed(half the time) than i would like but i mange with what i got. I also have 2 speedlights. Cheap ones, a yingyong(or something like that) only $15, no controls over it, as well as an oldish centron light with either full or half power. I do wish that one day i cant get a set of strobes, or at least a speed light with manual controls.

And my avatar i used just one of these lights