Why LED Lights Aren't Used in Camera Flashes/Strobes

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In summary, LED's are not used in modern camera flashes/strobes because they produce a spectrum of light that is not compatible with some of the absorption lines in neodymium-based laser media.
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RNickl
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Any input on why LED's are not used in modern camera flashes/strobes? I've searched a bit and it seems newer multi-die LED arrays not only put out more light but can strobe faster than xenon lamps, sounds win/win? I feel I must be missing something?!

I was considering trying to modify a small flash I have by getting rid of the xenon and placing LED's direct into a lighting diffuser mounted on the front of the lens. It would make my light setup for macro photography WAY more manageable and durable.
 
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  • #2
RNickl said:
Any input on why LED's are not used in modern camera flashes/strobes?
Size, maybe? Focus?
 
  • #3
Xenon seems to have a number of advantages.

https://en.wikipedia.org/wiki/Flashtube#Xenon said:
Xenon[edit]
220px-XeTube.jpg

Xenon, operated as a 'neon light,' consists of a collection of mostly spectral lines, missing much of the continuum radiation needed for good color rendering.
220px-Flashlamp_ion_spectral_line_radiation_output.jpg

Spectral line radiation from a xenon flashlamp. Although invisible to the naked eye, the digital camera is able to image the strong, IR spectral-lines, which appear as the blue light reflected off the table.
As with all ionized gases, xenon flashtubes emit light in various spectral lines. This is the same phenomenon that gives neon signs their characteristic color. However, neon signs emit red light because of extremely low current-densities when compared to those seen in flashtubes, which favors spectral lines of longer wavelengths. Higher current-densities tend to favor shorter wavelengths.[13] The light from xenon, in a neon sign, likewise is rather violet. The spectrum emitted by flashtubes is far more dependent on current density than on the fill pressure or gas type. Low current-densities produce narrow spectral-line emission, against a faint background of continuous radiation. Xenon has many spectral lines in the UV, blue, green, red, and IR portions of the spectrum. Low current densities produce a greenish-blue flash, indicating the absence of significant yellow or orange lines. At low current-densities, most of xenon's output will be directed into the invisible IR spectral lines around 820, 900, and 1000 nm.[14]Low current-densities for flashtubes are generally less than 1000 A/cm2.

Higher current-densities begin to produce continuum emission. Spectral lines broaden and become less dominant as light is produced across the spectrum, usually peaking, or "centered", on a certain wavelength. Optimum output-efficiency in the visual range is obtained at a density that favors "greybody radiation" (an arc that produces mostly continuum emission, but is still mostly translucent to its own light; an effect similar to sunlight when it passes through a cloud). For xenon, greybody radiation is centered near green, and produces the right combination for white light.[9][11]Greybody radiation is produced at densities above 2400 A/cm2.

Current densities that are very high, approaching 4000 A/cm2, tend to favor black-body radiation. Spectral lines all but disappear as the continuum radiation dominates, and output center shifts toward the ultraviolet. As current densities become even higher, visually, xenon's output spectrum will begin to settle on that of a blackbody radiator with a color temperature of 9800 kelvins (a rather sky-blue shade of white).[1] Except in cases where intense UV light is needed, such as water decontamination, blackbody radiation is usually not desired because the arc becomes opaque, and much of the radiation from within the arc can be absorbed before reaching the surface, impairing output efficiency.[11][14][15]

Due to its high-efficient, white output, xenon is used extensively for photographic applications, despite its great expense. In lasers, spectral-line emission is usually favored, as these lines tend to better match absorption linesof the lasing media. Krypton is also occasionally used, although it is even more expensive. At low current-densities, krypton's spectral-line output in the near-IR range is better matched to the absorption profile of neodymium-based laser media than xenon emission, and very closely matches the narrow absorption-profile of Nd:YAG.[16][17] None of xenon's spectral lines match Nd:YAG's absorption lines so, when pumping Nd:YAG with xenon, the continuum radiation must be used
 

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Thanks both for the input.
Spectral bandwidth is a very important consideration and not forgotten. Much easier to compensate for in these digital days but may still cause some issues.
 

1. Why aren't LED lights commonly used in camera flashes/strobes?

LED lights are not commonly used in camera flashes/strobes because they do not produce enough light intensity compared to traditional flash units. LED lights also have a lower color temperature, which can result in a cooler and less flattering light for photography. Additionally, the technology for LED lights in flashes/strobes is still relatively new and may not be as reliable or customizable as traditional flash units.

2. Can LED lights be used as a substitute for traditional flash units in photography?

While LED lights can be used as a substitute for traditional flash units, they may not produce the same quality of light. LED lights have a slower flash duration, which can result in motion blur and may not be suitable for capturing fast-moving subjects. Additionally, LED lights may not have the same level of control and versatility as traditional flash units, making them less ideal for professional photography.

3. Do LED lights have any advantages over traditional flash units in photography?

LED lights do have some advantages over traditional flash units in photography. They are more energy-efficient, have a longer lifespan, and can produce a continuous light source, making them useful for video and constant light setups. LED lights also do not produce as much heat as traditional flash units, which can be beneficial for prolonged use.

4. Are there any situations where LED lights are more suitable for photography than traditional flash units?

LED lights may be more suitable for certain types of photography, such as product or macro photography, where a continuous light source is needed. They can also be useful for photographers who prefer a cooler color temperature in their images. Additionally, LED lights may be more convenient for on-the-go or outdoor photography, as they do not require external power sources and can be battery-operated.

5. Are there any advancements being made in using LED lights for camera flashes/strobes?

Yes, there are ongoing advancements in using LED lights for camera flashes/strobes. Manufacturers are constantly improving the technology to increase light intensity and flash duration, as well as developing more advanced control options for LED lights. As LED technology continues to evolve, we may see them become more common in photography equipment in the future.

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