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Old January 11th, 2017, 09:24 AM   #31
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Re: Led diy?

Has anyone tried using variable color temperature LED strips, such as these https://www.superbrightleds.com/more...led-3528/1451/

Any problems with that?
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Old January 11th, 2017, 12:27 PM   #32
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Re: Led diy?

Variable color temperature LEDs sounds like a great idea, but there is no specs for it on its color accuracy. Then looking at the controller, it doesn't say how it's controlling it...variable voltage? Or pulse width modulation? If it's PWM, its supposedly better to be above 10K cycles in order to eliminate visible flicker on video. By looking at the specs alone (or lack of,) I can't tell if it'll work for video.
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Old January 11th, 2017, 05:59 PM   #33
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Re: Led diy?

Kathy, that connector is for laptop use. Although it supplies 19 volts DC you must also know the lower and upper voltage range of the led module or driver input range. Too high and you will smoke it, too low and the lights won't work, polarity mistake and poof more smoke perhaps. The dimming switches are connected to the drivers. One for the cool white leds and the other for the warm whites. The dimmers are connected directly with the driver boards ( the electronics that feed the led their proper dose of DC voltage). Like I said before, led are very particular about the voltage and MUST be within their operating range. The led drivers make sure of that ONLY IF THE FEED DC IN VOLTAGE IS WITHIN THE DRIVER'S INPUT RANGE. What does the spec sheet ( if you got one) say about the DC voltage input range ??
Also on that link to superbrightleds, if you follow the small print you will see it also needs the recommended driver ( not the remote) that accepts 5 to 24 volt DC as input ( the black lead as negative and red lead as positive) https://www.superbrightleds.com/more...schannel/3048/

You just cannot throw any value of DC voltage in. In that case a 12 volt or even a 7.4 volt DC camcorder battery will work as if falls WITHIN the DC input voltage range (5-24) of the recommended driver.
That laptop AC to DC power adapter you have shown can also be hard wired to the driver iF YOU KNOW WHICH WIRE IS + AND WHICH WIRE IS - after cutting off the end. Usually the centre pin is the + and the other is the -. A voltmeter will easily determine that. In many cases, as usual, the positive is the centre yellow or red shielded wire and the negative is the surrounding multi stranded silver shield. But do make sure with a DC voltmeter though.
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Old January 11th, 2017, 06:03 PM   #34
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Re: Led diy?

Come to think about it Kathy, wouldn't it be cost effective to get an on-camera led light that accepts batteries too and is dimmable with variable color temperature. Easy to diffuse as most come with a clip on diffuser ? But if you already started your project.........
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Old January 12th, 2017, 06:01 AM   #35
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Re: Led diy?

Quote:
Originally Posted by Arthur Gannis View Post
Kathy, that connector is for laptop use. Although it supplies 19 volts DC you must also know the lower and upper voltage range of the led module or driver input range. Too high and you will smoke it, too low and the lights won't work, polarity mistake and poof more smoke perhaps. The dimming switches are connected to the drivers. One for the cool white leds and the other for the warm whites. The dimmers are connected directly with the driver boards ( the electronics that feed the led their proper dose of DC voltage). Like I said before, led are very particular about the voltage and MUST be within their operating range. The led drivers make sure of that ONLY IF THE FEED DC IN VOLTAGE IS WITHIN THE DRIVER'S INPUT RANGE. What does the spec sheet ( if you got one) say about the DC voltage input range ??
Also on that link to superbrightleds, if you follow the small print you will see it also needs the recommended driver ( not the remote) that accepts 5 to 24 volt DC as input ( the black lead as negative and red lead as positive) https://www.superbrightleds.com/more...schannel/3048/

You just cannot throw any value of DC voltage in. In that case a 12 volt or even a 7.4 volt DC camcorder battery will work as if falls WITHIN the DC input voltage range (5-24) of the recommended driver.
That laptop AC to DC power adapter you have shown can also be hard wired to the driver iF YOU KNOW WHICH WIRE IS + AND WHICH WIRE IS - after cutting off the end. Usually the centre pin is the + and the other is the -. A voltmeter will easily determine that. In many cases, as usual, the positive is the centre yellow or red shielded wire and the negative is the surrounding multi stranded silver shield. But do make sure with a DC voltmeter though.
Arthur,
I bought everything exactly the same the guy specifies in the video. That SHOULD work as it worked for him. Yes, the connector is for laptop use, it's exactly what the guy uses in the video. I'm not throwing just any voltage at it. It is 19 volts, since this is a bicolor panel each color temp strip receives under 12v which is less than what is required, that way the lights won't run too hot but still be bright enough.
I won't be using a battery pack with the first lights I build, I will leave for the next project.
As for the variable color temp LED strips, I think I will pass on that too as reading the reviews it seems that the changing of color temp can be only done in big increments and that might be of a concern for video work. I'll stick with the LEDs the guy used in the video.

Quote:
Originally Posted by Arthur Gannis View Post
Come to think about it Kathy, wouldn't it be cost effective to get an on-camera led light that accepts batteries too and is dimmable with variable color temperature. Easy to diffuse as most come with a clip on diffuser ? But if you already started your project.........
On camera LED, you mean one that fits in a hotshoe?
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Old January 18th, 2017, 09:09 AM   #36
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Re: Led diy?

Hey there Kathy, sounds like Arthur is trying to discourage you for whatever reason by suggesting you buy an on camera light. I don't understand the point of that as I too hope to start a similar project soon. I have been waiting on some high CRI strips and a controller that is being developed through a group buy on Reduser. I have been wanting to do this for a few years now since I first saw a crew doing stills with some lightgear panels on the set of Magic City. Let us know how your project is going.
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Old January 19th, 2017, 04:40 AM   #37
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Re: Led diy?

Quote:
Originally Posted by Arthur Gannis View Post
Come to think about it Kathy, wouldn't it be cost effective to get an on-camera led light that accepts batteries too and is dimmable with variable color temperature. Easy to diffuse as most come with a clip on diffuser ? But if you already started your project.........
Quote:
Originally Posted by Mark Bolding View Post
Hey there Kathy, sounds like Arthur is trying to discourage you for whatever reason by suggesting you buy an on camera light. I don't understand the point of that as I too hope to start a similar project soon. I have been waiting on some high CRI strips and a controller that is being developed through a group buy on Reduser. I have been wanting to do this for a few years now since I first saw a crew doing stills with some lightgear panels on the set of Magic City. Let us know how your project is going.
Yeah, I'm not sure why on camera light would even be recommended as a substitute, obviously it's a completely different thing.

I'm still waiting for my LED strips to show up. I'm hoping they will arrive by the end of the month.
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Old January 19th, 2017, 10:53 PM   #38
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Re: Led diy?

I have seen many use an on-camera light for diffused light quality such as portraiture and table top commercial/catalog video or photo work. Just because it is labeled as a camera top light doesn't mean it has to be mounted on a camera. One can easily mount it on a tripod with swivel head and use whatever diffusion material needed in the front. Most already include a diffuser that either clips in place at the front or if it is too small can always be put in a soft box or small umbrella. The issue I have seen with strip lights is that 1- their color rendering index or CRI is not up there in the +90 CRI index and 2- Once you got that perfect mix of balancing both cool and warm led going, dimming to a higher or lower value will require a color re-balancement again every time you need to dim/brighten the unit. In many camera-top lights once you set the required color temperature using one knob you can dim or brighten at will without affecting the color. I am not talking about discouraging, I just wanted to offer a possible alternative. I have designed and built many on and off camera professional led lights and most of my on-camera units went eventually to be used on a tripod ( off-camera) with a scrim/diffuser at the front. God luck with your project and if you need technical advice just let me know.
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Old January 20th, 2017, 12:42 AM   #39
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Re: Led diy?

LED lights are great until you start to defuse them. (especially the small ones) You preferably need powerful ones so the light can get through the defuser. Those frosted perspex ones ore so close to the LEDs they only reduce the amount of light that gets through. I mean look at a proper light box it spreads the light from the source the bare light about 9 inches to the white defuser anything over 2 feet and because its more powerful shines brighter through the defuser.

The LED roll seems a good idea as you could make it as big as you want. Thus acting as a defuser.
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Old May 27th, 2017, 07:51 AM   #40
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Re: Led diy?

Hi,

I'm almost done building my light BUT I'm having a really hard time finding a 4 conductor either 18 or 20 AWG black (ideally pretty flexible) cable. Anyone has any clue where one might find such cable?

Thanks
Kathy
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Old May 27th, 2017, 01:09 PM   #41
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Re: Led diy?

This is directed at some of you electronic buffs. Would telephone cable be able to carry enough oomph? Or would it just melt?
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