Alzo 300 LED light

That light is rated at 100 watt draw. Is that the unit's power draw or the Led power draw when at full brightness ?? doesn.t say. If the unit draws 100 watts from the power supply source ( your wall outlet), then approximately 80 watts go into the led itself. You have that approximation of 20% loss in the led driver circuitry efficiency loss, fan, electronics. Assuming that 80 watts go into the led and that led emits 80 lumens per watt ( 80 lumens per watt is being generous for a single large die led, actually the led is made up of 100 tiny square leds 10X10 segmented that has a 10S10P circuit connection). Leds in this calibre typically have 60-70 lumens per watt. So, now that led now has the potential of 80watts X 80 lumens/watt which is 6400 lumens tops. Converting the lumens to luxes requires a projected ( beam) angle as well as a distance. No beam angle, no distance therefore no calculation of luxes.
Now, if 100 watts go into the led, then we have a unit of 8000 lumens. Even so, without a light meter, lux meter or measuring apparatus of light, the unit is between 6000 to 8000 lumens.
A common kitchen 100 watt filament bulb emits 1600 lumens. Do the math, that unit is between 375 and a 500w at best. Assuming the reflector supplied has a 45 degree beam, now I can easily calculate the luxes and eventually the FC's ( foot candles) . I can also subtract a 5-10% reflector loss, but I won't to give it the benefit of a doubt. at the 8000 lumen level (tops) I get 1858 luxes @ 10 ft. or 170 foot candles @10ft.
I welcome any corrections in my calculations.
 
My unit is stuck at German customs. When I have it I'll borrow a light meter and we'll have some real life numbers.

If this is a rebranded Chinese developed device, I'm absolutely certain the numbers are very "rough" estimates and surely not conservative (just worked for a Chinese production and the storyboard and all instructions even after asking twice were ridiculously unprecise for western standards).

In perspective, it's still a very affordable light and probably doesn't have to be a winner at all disciplines.
 
I have tried many 100W led emitters from China and also from the best of the best as far as large area LED dies from Cree and Bridgelux and have only been able to muster a maximum 8750 lumens from the rated 100W led using a borrowed integrated sphere set-up. Even at that, I was driving the led at 100% rated input current and Fv ( forward voltage) with a regulated lab quality power supply. To be able to say that a led is equivalent to a 1000 or a 1K filament , it needs to shell out a whopping 16000 lumens. No small feat. If one day in the not too distant future a led, or series of can emit 160 lumens per watt efficacity, then we can enjoy a 1K light that only draws 100 watts for a 1:10 ratio.
By then the LEP would probably be in the limelight.
 
Norman99 said:
I have tried many 100W led emitters from China and also from the best of the best as far as large area LED dies from Cree and Bridgelux and have only been able to muster a maximum 8750 lumens from the rated 100W led using a borrowed integrated sphere set-up. Even at that, I was driving the led at 100% rated input current and Fv ( forward voltage) with a regulated lab quality power supply. To be able to say that a led is equivalent to a 1000 or a 1K filament , it needs to shell out a whopping 16000 lumens. No small feat. If one day in the not too distant future a led, or series of can emit 160 lumens per watt efficacity, then we can enjoy a 1K light that only draws 100 watts for a 1:10 ratio.
By then the LEP would probably be in the limelight.
Click to expand...

Yeah, I have always been skeptical about the equivalent output claims from CFL and LED manufactures. There are so many variables in the light output from a bulb and fixture combination. For example, in the testing of my lights I found that a single 300 watt clear bulb R-30 reflector photoflood puts out more light, as a read by a light meter, than does a 650 watt DYS bulb in an open faced fixture. I agree that there is no way that the Alzo lights and the others are exactly equivalent to many specific 1K bulbs and fixtures, but they do put out a lot of light; especially for the money.
 
David, incase you or others are curious to know, an Alzo 4 bank at full blast (with included grid) @ 10 feet puts out 30 footcandles.

I also tested a 575w Source 4 and at 25 feet with 19 degree beam angle its around 120 fc. The documentation shows 392 fc with 750w bulb but I have not been able to confirm that.
 
Norman99 said:
That light is rated at 100 watt draw. Is that the unit's power draw or the Led power draw when at full brightness ?? doesn.t say. If the unit draws 100 watts from the power supply source ( your wall outlet), then approximately 80 watts go into the led itself. You have that approximation of 20% loss in the led driver circuitry efficiency loss, fan, electronics. Assuming that 80 watts go into the led and that led emits 80 lumens per watt ( 80 lumens per watt is being generous for a single large die led, actually the led is made up of 100 tiny square leds 10X10 segmented that has a 10S10P circuit connection). Leds in this calibre typically have 60-70 lumens per watt. So, now that led now has the potential of 80watts X 80 lumens/watt which is 6400 lumens tops. Converting the lumens to luxes requires a projected ( beam) angle as well as a distance. No beam angle, no distance therefore no calculation of luxes.
Now, if 100 watts go into the led, then we have a unit of 8000 lumens. Even so, without a light meter, lux meter or measuring apparatus of light, the unit is between 6000 to 8000 lumens.
A common kitchen 100 watt filament bulb emits 1600 lumens. Do the math, that unit is between 375 and a 500w at best. Assuming the reflector supplied has a 45 degree beam, now I can easily calculate the luxes and eventually the FC's ( foot candles) . I can also subtract a 5-10% reflector loss, but I won't to give it the benefit of a doubt. at the 8000 lumen level (tops) I get 1858 luxes @ 10 ft. or 170 foot candles @10ft.
I welcome any corrections in my calculations.
Click to expand...

The spec on the light is 9000 Lux at 1 meter, no mention of beam angle though. It is 5600 K daylight balance though, so if you are comparing to tungsten it should include the loss of a CTB filter.
 
"The spec on the light is 9000 Lux at 1 meter, no mention of beam angle though. It is 5600 K daylight balance though, so if you are comparing to tungsten it should include the loss of a CTB filter."

The light is not 9000 lux at 1 meter. It's 9000 lumens. Huge differenece.

Exactly. So now that 5600K reduced to a warm 3200K with filtration will lose a full stop of light, making it way less that the claimed 9000 lumens.
Another way of looking at it is that it needs to be way over 9000 lumens in order to be equivalent ( with filtration) to the 1000W 3200K filament.
A 1K (1000W) filament tungsten 2700-3200K bulb, is considered 16,000-1800 lumens irregardless of distance or beam angle. Once that light ( lumens) is collected/collimated to a specific beam diameter ( function of angle) and at a specified distance, then the brightness can be measured as luxes. Luxes can easily be converted to Fc's (foot candles) by multiplying by .092
Slapping around inflated numbers in spec sheets is easy to do, especially high CRI figures. But that's another story for another day.
 
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"9000 LUX at 1 m (3 feet)"

with a beam of 45° that would make 4300 lumen
beam of 30° roughly 2000 lumen
beam of 60° about 7500 lumen

no idea what beam angle it has
 
A little typo correction was done but it did not save the changes.
should be:

Exactly. So now that 5600K reduced to a warm 3200K with filtration will lose a full stop of light, making it way less that the claimed 9000 lux.
Another way of looking at it is that it needs to be way over 9000 lux in order to be equivalent ( with filtration) to the 1000W 3200K filament.
A 1K (1000W) filament tungsten 2700-3200K bulb, is considered 16,000-1800 lumens irregardless of distance or beam angle. Once that light ( lumens) is collected/collimated to a specific beam diameter ( function of angle) and at a specified distance, then the brightness can be measured as luxes. Luxes can easily be converted to Fc's (foot candles) by multiplying by .092
For that light to be a 1K equivalent ii has to measure in the area of 33,000 luxes with a 45 degree reflector at 1m with 16,000 lumens light source.
Even with a 60 degree beam and 7500 lumens feeding it, it's still 8,500 lumens short. I highly doubt if that reflector is wider than 60 degrees.
That reflector has to be 88 degrees wide with a true measured lux value of 9000 lux at 1 meter to be a 1000 watter (16,000 lumens). Anything narrower and no dice. And that is assuming a perfect reflector with no reflectivity loss.

Slapping around inflated numbers in spec sheets is easy to do, especially high CRI figures. But that's another story for another day.
 
I have not had a reply from Alzo re: beam angle, etc.
It would sure be nice for them to chime in on this thread.
Ken
 
Norman99 said:
A little typo correction was done but it did not save the changes.
should be:

Exactly. So now that 5600K reduced to a warm 3200K with filtration will lose a full stop of light, making it way less that the claimed 9000 lux.
Another way of looking at it is that it needs to be way over 9000 lux in order to be equivalent ( with filtration) to the 1000W 3200K filament.
A 1K (1000W) filament tungsten 2700-3200K bulb, is considered 16,000-1800 lumens irregardless of distance or beam angle. Once that light ( lumens) is collected/collimated to a specific beam diameter ( function of angle) and at a specified distance, then the brightness can be measured as luxes. Luxes can easily be converted to Fc's (foot candles) by multiplying by .092
For that light to be a 1K equivalent ii has to measure in the area of 33,000 luxes with a 45 degree reflector at 1m with 16,000 lumens light source.
Even with a 60 degree beam and 7500 lumens feeding it, it's still 8,500 lumens short. I highly doubt if that reflector is wider than 60 degrees.
That reflector has to be 88 degrees wide with a true measured lux value of 9000 lux at 1 meter to be a 1000 watter (16,000 lumens). Anything narrower and no dice. And that is assuming a perfect reflector with no reflectivity loss.

Slapping around inflated numbers in spec sheets is easy to do, especially high CRI figures. But that's another story for another day.
Click to expand...

I was looking at it the other way round. You lose a stop on a tungsten light filtering for daylight balance, which would make the Alzo roughly equivalent to a 1k tungsten with a daylight filter. In any case it is a very bright cheap led par and from the review and samples Dustylense posted seems to perform pretty well for CRI too.
 
In more practical terms I'd say most people have good, cheap and effective 3200 tungsten lights. I would think that anyone looking to get a daylight balanced fixture would be doing so for the daylight color temperature, to have the ability of providing some key or fill mixed in with existing daylight sources. So I'm not sure why I would compare the output of this light with CTB to anything.. other than to purely make all things equal in terms of color temperature.
 
Here's another thought, just had a look at how the Chinese were doing with their ARRI knockoffs, and jesus they are cheap...

http://www.ebay.com/itm/Pro-As-ARRI...256?pt=LH_DefaultDomain_0&hash=item4ac6733678

and they all come with inline dimmers!

i recall the fella that awhile back reviewed some knockoffs and the quality was off course knocked off, wondering if they've made some improvements. One feature i was on earlier this year was done all with arri knockoffs and no tragedy befell us, just some light leakage from the housing
 
Sure there are (cheap) alternatives but tungsten hot lights really are a different workflow.
 
What I am seeing more of is a demand for battery operation high brightness light units. After talking with many pros in the media film/photography business, I found that there is a dividing line between 2 different areas of lighhting set-ups. One one hand there are those who demand high brightness, quality of light, DMXable ( if that word exists), and don't mind the umbilical powering cord(s) to the wall/generator or the high price of the units. They don't have the need for rush "run'n gun" or mind taking the time to set-up/take-down equipment & lugging a little extra weight around. Then there are those who want a quick set-up, battery operation ( AC powered possibility in case of backup from battery depletion) and desire a decent light output that is suitable for distances of 20ft. or less. They also do most of their work with a 2-3 light set-up for close range interviews/ company product training, or small area business advertisements. Price matters but don't want cheap units that fall apart.These are the run and gun types that, after interviewing them on what constitutes their main income from the trade as far as their assignments and way of execuing them, they all seem to agree on importance of agility, minimal equipment, weight, reliability and compactness. Their dream outfit must all be in one luggage on wheels including the camera and tripods. This way if their vehicule is parked at a distance, they can just wheel in one single luggage without the help of an assistant. As far as the lights go, they are comfortable with just a 500W equivalent key, another 500w fill and a back narrowed beam hairlight 250W. Most of them only carry 2 lights and in many instances use only one. Here is what was averaged out as far as the light(s) specs. desired.

1- Battery operation from 14.4 V mounts or similar
2- 90 minutes MINIMUM run time at full brightness, and the ability to swap battery without power interruption.
3- 400W minimum bulb equivalent ( or 7K lumens)
4- LED color control from 2700K to 6000K
Most use compact cameras Sony EX3-5, AF100's, NEXEA50 etc. and the DSLR's.
This discussion was brought up several times at meetings, seminars and group gatherings in the NJ area.
They all agree that battery operation is a must for their style of shooting.
Batteries are also improving in weight and capacity.
Camera sensors are constantly improving for low light performance.
LED efficacity is going up.
Remote phosphor is here already.
The LEP is on the horizon.
What about the good ol' filament bulb?
 
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