18

Those are LED panels specifically made for photo or video lighting. They are spec'd as "flicker-free" and use DC, so there's no AC flicker, and i assume dimming isn't performed via PWM, but reduced current. That's very different to a simple and cheap household LED lamp, which uses much simpler electronics and works off AC.


13

LEDs don't create flicker from nothingness. They only flicker if their drive current varies. It's not really a matter of new technology. The technology to make constant current drivers with reasonable efficiency has existed far longer than LEDs suitable for illumination purposes have existed. The reason many LED lights flicker is because it is cheaper to ...


10

Another possible use of a double-led flash is to fiddle with the light color temperature. There is an implementation in the dual LED flash in the iPhone 5S. The idea is having two sources of light with different color temperatures (say, daylight and a reddish one) and to balance them to have a more natural "fit" with the ambient color temperature when ...


9

LEDs emit a narrow frequency band of light. Digital cameras detect color by looking at black and white luminance (brightness) sensors that go through a grid of colored filters (red, green and blue). If the frequency of light from the LED is narrow enough and doesn't match up well with the filters on the sensor, you can get odd looking color as the narrow ...


8

While it is true that if you're shooting only under red light your camera will collect less light than if you had full spectrum lighting you must also keep in mind that all of the light you are collecting is mostly going into only a quarter of your sensor's pixel wells. The lack of green or blue light in the scene doesn't increase the amount of red you can ...


8

This is something specific to photographing LEDs. Most LEDs aren't on all the time, but are in fact flashing extremely rapidly. The ratio of on/off time (the duty cycle) can be used to control the perceived brightness of the LED. The camera you are using has a rolling shutter. When your camera takes a photo, it actually scans the image from top to bottom (or ...


7

The easiest answer is "time". You don't need to amplify anything: you just need to collect it for longer. The overall exposure of your photo is the amount of ambient light that is accepted through the camera's aperture for the amount of time the shutter is open. Presuming that your object doesn't move, simply take either one long exposure or a sequence of ...


6

LED flicker There is no such thing as "LED" flicker. Every light source can flicker (although not every can flicker fast enough). Flicker is created by turning a light source on and off, it's a property of a power source, not a light source. Take same LED, on DC it won't flicker, on PWM it will. Make the PWM too slow or too fast and it appears to ...


5

It can definitely be a problem, especially if the LED lights in question are not white LED lights. White LED lights, at least the higher quality ones, put out enough red, green, and blue light to work fairly well for most cameras. The results might not be as ideal as a fuller spectrum light source, but you can usually get pretty close. Typical high quality ...


5

The real answer is 'depends'. White LED usually consists of phosphor (react with the chip emission) layered on a diode (such as GaN, which emits violet light 405nm) that's why they are white. The phosphor gets activated by the light from the chip and emits another wavelength of light, hence different colour in a mixture to produce white. Wavelength of ...


4

The best way would be to buy a Light Meter that specifically can measure color temperature. Something like a Sekonic C-500 for example. With a tool like that you can properly measure the ambient sources and determine their kelvin values. Then with that knowledge you can adjust your own lighting to match the desired ambient level(s). You might have clicked ...


3

You have diferent issues here. Lets separate them. 1) You have a bright wall and dark people... It is the same case as if you have a bright window with people on an interior. Your options are limited. Use aditional ilumination, like firing a flash as fill light. If you are shooting from far away this could not work. But if you have permissions you can use ...


3

I really don't understand well what is your experiment. There are a lot of factors to consider, for example diffraction, which varies depending on the size of the aperture for example. To "increase" the light source (optimize, actually) I would recommend a parabolic mirror. A headlight of a car could work. Another option is not to use a led light ...


3

Images seen on computer screens, TV, phone, and other image display devices are comprised of glowing spots of colored light. The method we now use is the brain child of a Scottish scientist, James Clerk Maxwell. His paper of 1855 paved the way; the first color photograph was made in 1861. Maxwell’s theory of human color vision is based on the fact that any ...


3

The only way to know is to test your lights to see if they work well together. Lights that are rated the same temperature may not be. Lights that are the same temperature may differ along the green-magenta axis. Lights that are the same temperature may have different Color Rendering Indices.


3

Lighting stands are pretty much standard; almost everything that you would be using outside of industrial applications (like "real" cinema, television and theatre llighting) will use "baby" spigot connections (5/8" or 16mm). "Junior" is ultra-heavy-duty for lights weighing in the tens of kilos, and "senior" would be handy for supporting small armoured ...


3

You appear to have actually two [& a half] separate issues caused by the same thing. Firstly the blue spots - which, btw, won't do you any harm so long as you don't stare directly into the light a lot. The bulb appears to have several distinct LEDs inside it - not uncommon at all, & you would probably never notice in normal use, but for this ...


2

None of above answer explain the dual lighting vs single lighting. Single led can have twice the power of the dual led. Regardless the brightness, dual led can control the contrast ratio of a 3d object, and the darkness of the shadow. If taking flat copy, one illuminate from left while one from right, this makes the brightness of the flat object even. ...


2

Absolutely! You're using this for a video setup, but it's common in still photography with strobes, where this technique is known as "bounce flash". The caveat is that strobes — like from studio lighting, from hotshoe flashes, or even from the popup flash of a camera — are very short intense bursts of light. Your lamp, and probably even your spotlight, won'...


2

It will work after a fashion, but you'll get substantial reduction in light level when the light is reflected. In your application it may well be adequate. If you wish to use a diffuser you do not need a formal or commercial one. The paper that you intend stick on the wall could be used instead as a diffuser - it may prove too opaque, but it's easily tried....


2

The true-tone flash works for photos as well as while recording a video. If you start recording a video with the flash on, it should stay on and you could point it at the subject while taking the picture just like you would with it in 'torch mode.' Then just delete the video off of your phone after. You could also consider just doing a long exposure instead ...


2

I didn't know I could do this with my Android phone until I read your question and tried it. On my Android I have an app called 'Torch' that let's me use my phone as a flashlight. It just turns the camera's flash on and it's a good powerful flashlight. It seems that if I turn 'Torch' on before I take a picture, I'm accomplishing what you asked. The scene ...


2

Your ways are: using any film to record images instead of digital technology using the camera with strong enough AA filter using the camera with surplus of resolution (medium format cameras, may be very expensive) using very tight aperture (big F number) so that image is blurred enough with diffraction for moire to disappear. 1,5x crop camera with F13 will ...


2

Getting a bit more technical than Michael's excellent answer... Here are the spectral curves for a red LED and a Roscoe red filter. You can see the dramatic difference in spectral range. This may not matter much if there's no other illumination in the scene (i.e. standard light meter might see both as 'pure red'), but if you look up similar curves for ...


2

Most likely reason is the diode is overexposed. That would cause (the red channel) to be blown and the red color will appear faded. Decrease the exposure. Depending on what else is in the shot, the white balance could also be off. You can test that by including a white or grey card in the shot and checking and correcting in post.


2

Just me, but probably not. LED continuous lighting, particularly if we're talking little panels, tend to have relatively low light output and would be insufficient to match sunlight no matter what camera/lens combination you were using. f/1.4 is nice, but you can buy f/1.4 for MFT, and moreover aperture affects any light source. While it might help brighten ...


1

It looks to me, the photographer used a strobe flash off camera and posssibly laid on the ground or maybe on a chair set at wide to normal aimed at the two middle palms taken on a B (bulb setting) for about 30 to 60 seconds at either 400iso @ f1.4 lens opening or 1600iso at f1.4 lens opening.


1

Another difference: pulsing artifacts when used for stage lighting. LEDs arrays are dimmed/colored by being pulsed at full power rather than run continuously at partial power. While this is also how modern tungsten dimmers work, tungsten (and phosphor-based LEDs) tend to produce light that is an average of the power input. The RGB composition LEDs in ...


1

@Rafael hit the money on the head with his answer, but there is one thing that might be added: Fill flash to help bring in faces. It can be at angles so the faces are more side lit, rather than frontally, which would spill and reflect from the LED array. A key technique is to focus on, or slightly in front of the faces, so they are tack sharp or at ...


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