Author Topic: Which cheap Amazon LED's are recommended?  (Read 704 times)

JeffW

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Which cheap Amazon LED's are recommended?
« on: May 28, 2017, 02:08:51 PM »
Hey David!

Camera looks awesome. I'm about to order a few LED panels for filming high speed. The NEEWER panels look decent. Is there a problem using these (with a dc power source) shooting at 1,000-10,000fps on Chronos?
Any other recommendations?

Jeffism

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Re: Which cheap Amazon LED's are recommended?
« Reply #1 on: May 28, 2017, 09:49:06 PM »
Just had a look at a few product specs for the Neewer lights and they all seem to say "constant current drive" which should work with high speed filming. Most (if not all) lights designed for video should use constant current; most LED flashlights/torches have moved from PWM to constant current, so the chips and designs are cheap and plentiful now.

I'm going DIY for starters. I already have rolls of cheap LED light strips (usually around $5-10 for 5m) just need to connect them to 12V, good for flood or fill lighting. Otherwise I'm just going outside, get plenty of sunlight where I live, even during the cold months. Simple just to place a few reflective panels around to concentrate the light if necessary.

DerpykV

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Re: Which cheap Amazon LED's are recommended?
« Reply #2 on: May 29, 2017, 11:08:35 AM »
You need to make sure the LED's power supply has enough filtering on the output, and that the driver is not overloaded. Some crappy leds will flicker at full power due to the leds discharging the caps before the next fill from the ac input.
I've seen some leds with no drivers and they look horrendous.

Cheers,
Max
« Last Edit: May 29, 2017, 04:34:49 PM by DerpykV »

DerpykV

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Re: Which cheap Amazon LED's are recommended?
« Reply #3 on: May 29, 2017, 11:09:39 AM »
Or they will use PWM to dim which sucks too

gyppor

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Re: Which cheap Amazon LED's are recommended?
« Reply #4 on: May 29, 2017, 11:45:14 AM »
JeffW,

Is your application strictly for mobile use?

If not and you have access to power outlets where you intend to film, I can recommend halogen work lights. They're cheap, very bright and most importantly, they don't flicker on high speed video despite running on AC.

The only downside is they produce a lot of heat, I usually turn them off between shots if I can.

G

JeffW

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Re: Which cheap Amazon LED's are recommended?
« Reply #5 on: May 31, 2017, 12:43:49 PM »
Thanks so much Jeff, Derpy and Gyypor!
Great idea to use halogens, hadn't thought of that. It's mostly sunlight work with some indoor shooting during the winter. Calgary barely sees the sun in the cold months :(

JamesB

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Re: Which cheap Amazon LED's are recommended?
« Reply #6 on: May 31, 2017, 05:06:52 PM »
I have a few of these lights to shoot high speed with. Even at over 10,000fps it has no detectable flicker which is ideal.  They are very bright "About 700 tungsten watts equivalent" and fairly priced. None have gone bad in over 2 years but I've heard of some failing under a year after heavy use in very hot weather.  So keep them cool, they have a fan and heatsink inside even when they do not emit much heat compared to HMIs or Halogen for example.  They are also compatible with the Bowens mount so if you have softboxes and diffusers there are easy to adapt. I have a snoot, softboxes and grids.





Link Here: http://amzn.to/2rVKUBy    $199.00


wilheldp

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Re: Which cheap Amazon LED's are recommended?
« Reply #8 on: August 27, 2017, 04:30:22 PM »
Since I don't have my camera yet, and I'm obsessed with it already, I decided to get a high-powered LED studio light to play with until my camera arrives.  I depends on your definition of "cheap," but in terms of studio-grade lighting, the light I bought was relatively cheap at $250 for 150 watts of LED.   I bought a Godox SL-150W and an NG-10X Fresnel lens (https://www.amazon.com/Godox-Daylight-Continuous-Controller-Protective/dp/B01MSQP7VZ/ref=sr_1_1?ie=UTF8&qid=1503875625&sr=8-1&keywords=godox+sl-150w and https://www.amazon.com/EACHSHOT-NG-10X-Professional-Fresnel-focusing/dp/B01K1CGKC8/ref=sr_1_1?s=electronics&ie=UTF8&qid=1503875760&sr=1-1&keywords=ng-10x).

I think the 150 watt version of the Godox SL series is the best deal.  It's only ~$15 more expensive than the 100 watt version, but $100 less than the 200 watt version.  It comes with a reflector to focus the beam, and the ~$35 fresnel lens focuses it even more.  I took several light level readings at ~1 meter using a cheap light meter.  For reference, I sat my light meter on the ground outside my house in direct sunlight at about 2 pm, and it showed a reading of ~60,000 lux.   From what I read, direct sunlight should be in excess of 100,000 lux, so either the sun was too low for my measurement, the light meter is horribly uncalibrated, or I did something wrong.  All of which are equally likely, but all of my readings were made using the same meter with the same meat-head operating it, so that should eliminate two of the variables. 

Below are my readings with the light set to 10%, 25%, 50%, 75%, and 100% power with no attachments, the included reflector, and the fresnel lens set to its lowest and highest settings.  Long story short, with the fresnel lens at its highest setting, the Godox light has roughly half of the intensity of bright sunlight.  Also, you have a pretty good spread of light levels from 700 to 30,000 lux for <$300.

Light set to 10% power:
No attachment -  700 lux
Reflector -     1100 lux
Fresnel (min) - 2500 lux
Fresnel (max) - 3500 lux


Light set to 25% power:
No attachment - 1200 lux
Reflector -     2300 lux
Fresnel (min) - 5400 lux
Fresnel (max) - 7700 lux


Light set to 50% power:
No attachment -  2100 lux
Reflector -      4100 lux
Fresnel (min) - 10000 lux
Fresnel (max) - 14500 lux


Light set to 75% power:
No attachment -  2500 lux
Reflector -      6000 lux
Fresnel (min) - 14800 lux
Fresnel (max) - 22300 lux


Light set to 100% power:
No attachment -  3800 lux
Reflector -      8000 lux
Fresnel (min) - 19400 lux
Fresnel (max) - 30000 lux


I also did a crude test for flicker.  I hooked a solar cell up to a oscilloscope, and placed it directly in front of the LED.  I measured a 40 millivolt peak-to-peak oscillation at ~100 megahertz, but I think that it was actually the noise floor of the scope that I was seeing.  There was no noticeable flicker at any but the lowest vertical resolutions on the scope, and certainly no 60 Hz flicker making it through the power supply.  The proof will be in the pudding if I see some flicker at high frame rates once my camera arrives.  Flicker was my main concern buying a cheaper LED light, and my preliminary testing has made me cautiously optimistic.
« Last Edit: August 27, 2017, 04:36:19 PM by wilheldp »

thebishop

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Re: Which cheap Amazon LED's are recommended?
« Reply #9 on: September 17, 2017, 12:28:17 AM »
Thanks for the detail!

Could you possibly try measuring with the fresnel in the middle of the zoom range? According to https://www.youtube.com/watch?v=7JuitNXvtQI it actually provided brighter light in the middle of the range (!).