Topics

Manufacturers specifications

Geoff Boyle
 

Why is it so hard for lighting manufacturers to list lamp specifications.

 

Some list output in Lumens output, some have charts with FC at feet at LUX at Mtrs.

 

Some use one for one lamp and another for a different lamp.

 

How on earth are we supposed to decide what we want to use?

 

 

Cheers

 

Geoff Boyle NSC FBKS

Cinematographer

Netherlands

www.gboyle.co.uk

 

 

Thomas Townend
 



On 22 May 2018, at 08:49, Geoff Boyle <geoff@...> wrote:

How on earth are we supposed to decide what we want to use?


This is a problem across all manufacturers/suppliers in all industries. 

I needed to buy a carry-on suitcase last month and nearly went spare trying to compare spec’s, dimensions & volumes across a range of leading manufacturers who all used different metrics to describe their products. 

I just accept that the world is riddled with inaccuracies, inefficiencies and stupid people. 

People tend to list the impressive stats and obscure the ones that are trumped by rival/alternative products so as to unlevel the playing field for the unwitting or unobservant consumer.  It’s a combination of dirty marketing and ineptitude. 

Tom Townend,
Cinematographer/London. 

 

And from 2020 in the EU, that will be crucial. Light sources making less than 85lm/W* will be outlawed. That means all tungsten, all fluorescent, and most LEDs. The manufacturers are scratching their heads on wondering which laws of science will need to be repealed.

Alan Roberts

* There are some exceptions allowed, such as panel lamps and sources making more than the equivalent of about 3KW of tungsten. But pretty well all the sources currently used for stage , film and TV will fall foul of this potential legislation.

On 22/05/2018 08:49, Geoff Boyle wrote:

Why is it so hard for lighting manufacturers to list lamp specifications.

 

Some list output in Lumens output, some have charts with FC at feet at LUX at Mtrs.

 

Some use one for one lamp and another for a different lamp.

 

How on earth are we supposed to decide what we want to use?

 

-- 
Alan Roberts - Mugswell, Surrey
+44 (0)1737832586
+44 (0)7749387934

John Rossetti
 

>> I just accept that the world is riddled with inaccuracies, inefficiencies and stupid people.

<< Amen

<<PS that includes Governments.

 

John Rossetti – Underground in London

 

John.rossetti@...

+44 7836 298 881

 

Peter Daffarn
 

Hi Geoff,

Speaking for a manufacturer it is equally as hard to decide what to use as your output figures.
Short of listing every option possible which I suspect would be equally confusing there is no standard.
Naturally given this every manufacturer will choose to use the system that gives the best for their fixture.
Lumen output is not much use as that is simply how much light is produced - not how well it is projected to the subject.

In my humble opinion what is important to you guys is how much light you get on your subject at a certain distance.
The area that light covers is equally important as I have noticed some manufactures quoting huge output figures which only apply to the absolute centre of the beam.

I for one would welcome some standardisation on how to quote light output figures.


Regards


Peter Daffarn
Managing Director
Photon Beard
UK

Geoff Boyle
 

Hi Peter,

 

Your opinion counts for a lot and you know the figures we need 😊

 

 

Cheers

 

Geoff Boyle NSC FBKS

Cinematographer

Netherlands

www.gboyle.co.uk

 

 

 

From: cml-lighting@... <cml-lighting@...> On Behalf Of Peter Daffarn

In my humble opinion what is important to you guys is how much light you get on your subject at a certain distance.

The area that light covers is equally important as I have noticed some manufactures quoting huge output figures which only apply to the absolute centre of the beam.

 

 

Steve Oakley
 

well don’t be like one big name light company whose specs of their fresnels at wide aren't actually full wide but partially spotted. of course there is text buried in the fine print at the bottom of the page to make it “honest”. if you rate a light that focuses, then wide should be as wide as the fixture goes because maybe we are looking at more than just raw output, but also how wide / even that output is at a given distance and need honest numbers. when I was testing the perfectly fine vision smith LED replacement “bulbs” I found this out after a lot of testing how numbers get played.

as for a standard, FC, lux and lumens. silly to have to convert units to make comparisons between brands but I suspect many newer companies like lumens because the numbers are bigger than lux or FC so it makes their stuff look good… unless you can do rough conversions in your head and realize what the numbers really mean.

Steve Oakley
DP / Editor / Colorist / VFX Artist
Madison & Milwaukee WI
920 544 2230


On May 22, 2018, at 3:02 AM, Peter Daffarn <peter@...> wrote:

Hi Geoff,

Speaking for a manufacturer it is equally as hard to decide what to use as your output figures.
Short of listing every option possible which I suspect would be equally confusing there is no standard.
Naturally given this every manufacturer will choose to use the system that gives the best for their fixture.
Lumen output is not much use as that is simply how much light is produced - not how well it is projected to the subject.

In my humble opinion what is important to you guys is how much light you get on your subject at a certain distance.
The area that light covers is equally important as I have noticed some manufactures quoting huge output figures which only apply to the absolute centre of the beam.

I for one would welcome some standardisation on how to quote light output figures.


Peter Daffarn
Managing Director
Photon Beard
UK

Ted Hayash
 

I've also found that frustrating - I've always suspected that it is the marketing departments that make the output figures. 

Ted Hayash
Cinematographer
Los Angeles

On Tue, May 22, 2018 at 7:31 AM Steve Oakley <steveo@...> wrote:
well don’t be like one big name light company whose specs of their fresnels at wide aren't actually full wide but partially spotted. of course there is text buried in the fine print at the bottom of the page to make it “honest”. if you rate a light that focuses, then wide should be as wide as the fixture goes because maybe we are looking at more than just raw output, but also how wide / even that output is at a given distance and need honest numbers. when I was testing the perfectly fine vision smith LED replacement “bulbs” I found this out after a lot of testing how numbers get played.

as for a standard, FC, lux and lumens. silly to have to convert units to make comparisons between brands but I suspect many newer companies like lumens because the numbers are bigger than lux or FC so it makes their stuff look good… unless you can do rough conversions in your head and realize what the numbers really mean.

Steve Oakley
DP / Editor / Colorist / VFX Artist
Madison & Milwaukee WI
920 544 2230


On May 22, 2018, at 3:02 AM, Peter Daffarn <peter@...> wrote:

Hi Geoff,

Speaking for a manufacturer it is equally as hard to decide what to use as your output figures.
Short of listing every option possible which I suspect would be equally confusing there is no standard.
Naturally given this every manufacturer will choose to use the system that gives the best for their fixture.
Lumen output is not much use as that is simply how much light is produced - not how well it is projected to the subject.

In my humble opinion what is important to you guys is how much light you get on your subject at a certain distance.
The area that light covers is equally important as I have noticed some manufactures quoting huge output figures which only apply to the absolute centre of the beam.

I for one would welcome some standardisation on how to quote light output figures.


Peter Daffarn
Managing Director
Photon Beard
UK

--
Ted Hayash
Director of Photography
www.tedhayash.com
Tel: 818 653-5786

 

Don't confuse units.

Lumens are the total light output of a source (i.e. over a sphere), while lux are lumens/square metre (i.e. light landing on a defined surface), they are not the same. Both are SI units and preferred over old units such as foot-candles.

Alan Roberts

On Tue, May 22, 2018 at 7:31 AM Steve Oakley <steveo@...> wrote:
as for a standard, FC, lux and lumens. silly to have to convert units to make comparisons between brands but I suspect many newer companies like lumens because the numbers are bigger than lux or FC so it makes their stuff look good… unless you can do rough conversions in your head and realize what the numbers really mean.
-- 
Alan Roberts - Mugswell, Surrey
+44 (0)1737832586
+44 (0)7749387934

Yann Cainjo
 

Hi Geoff

We (at CST in France) made in 2014 & 2016 a study about photometric and colorimetric performance of LED.

You will find in the both studies photometric data for main LED fixtures.

2016 study update :
http://www.cst.fr/wp-content/uploads/2016/04/Etude-CST-LED-2016-rapport-final-Internet-v2.pdf

2014 study :
http://www.cst.fr/wp-content/uploads/2014/06/etude_projecteur_LED_maj-20-01-15.pdf

Best regards
Yann

Yann CAINJO
Photographer & gaffer
Paris, France

Chester Simmons
 


I would think, as more and more lighting units are manufactured in China, that the quality/output of the lighting fixtures will vary from manufacturing run to manufacturing run, experiencing "quality fade",so that any printed output claims may or may not be accurate.   When corners can be cut, they often are, in order to maximize profits.   Here's a link to an article in the China Law Bog regarding a recent case regarding automobiles' hidden components.  


Interestingly, this past week, I was gaffing a job with the lighting sourced by the camera department from a rental house.  The 1200 HMI's were Arri knock offs.   The AC power cord from one of the 1200 ballasts pulled out from the metal case.  I noticed that there was no connection for the ground to the metal case…it simply was cut off, apparently by the manufacturer.   The head cable was the smallest gauge possible.  Yes, they worked, but these were hidden issues.  

I can only image that LED binning, basically sorting LED's by output color and intensity, and putting them into appropriate boxes to be installed in lighting units, will prove challenging for quality control.   

Chet Simmons
Gaffer
Las Vegas

 

Maybe not Alan..




Michael

Michael J Sanders: Director of Photography 
  

Mobile: +44 (0) 7976 269818   
Linkline Diary: +44 (0)20 8426 2200

On 22 May 2018, at 10:33, alan836975 via Cml.News <roberts.mugswell=btinternet.com@...> wrote:

And from 2020 in the EU, that will be crucial. Light sources making less than 85lm/W* will be outlawed. That means all tungsten, all fluorescent, and most LEDs. The manufacturers are scratching their heads on wondering which laws of science will need to be 

 

Emphasis on 'could be' and 'maybe'. The discussion document makes no reference to the entertainment industry as such, and that's why there's an uproar going on.

A

On 23/05/2018 12:04, Michael Sanders wrote:
Maybe not Alan..


On 22 May 2018, at 10:33, alan836975 via Cml.News <roberts.mugswell=btinternet.com@...> wrote:

And from 2020 in the EU, that will be crucial. Light sources making less than 85lm/W* will be outlawed. That means all tungsten, all fluorescent, and most LEDs. The manufacturers are scratching their heads on wondering which laws of science will need to be 

-- 
Alan Roberts - Mugswell, Surrey
+44 (0)1737832586
+44 (0)7749387934

Marc Galerne
 

I agree with Peter.
As a manufacturer I totally agree that it’s difficult to get a standard. Since the arrival of Leds a lot of BS has been printed in brochures by ignorant or worse, dishonest manufacturers. I have read statement of 200w Led fixtures being superior to a Joker 800!!! When I did the test, it was equivalent to a 200 w HMI Fresnel and that was before putting any diffusion and some minus green to have something usable.
Not many people know how to compare two lights. You need to make comparison at the same beam angle otherwise an 18 K Fresnel (which can be as narrow as 7 degree) will be more powerful in Spot than a faceted reflector (which as a  maximum 15 degree angle) and the opposite in flood as a Fresnel is over 60 degree and a lens less Par is 50. 
You define the beam angle by going from the center of the beam to 50% of the output which gives you a distance that you combine with the difference from the light to your light meter. How do you do this when you have lens less pars which produce a donut shape beam? You go from the center and go to twice the output?
Also, there are two ways of measuring the spread:
1) On a flat wall, you measure the center and move your light meter along a flat wall to the edge of the beam until you get 50% of the amount in the center.
2) You place the light meter on the wall and instead of moving it, you rotate the light until you reach 50% of the center reading.
Well, number 2 is favored by many manufacturers because, as the distance from the light to the meter remains the same you end up with a greater angle which in some ways is not wrong... if you shoot in a circular room.
Considering that most of the time, the walls are flat and not curved in real life and on set, we use technique number 1.
So, doing photometrics is more than just producing a light meter in front of a light.

I have very little faith in people really caring about all this any way.

A  very famous 400 W Led Light is claimed to be equivalent to a 6K spacelight. And everybody agrees... Seriously?
A 6kw of tungsten at even the lowest 15 lumen per watt is 90.000 lumen/watt. If a 400w unit is capable of producing the same amount it means it’s a 225 lumen/watt fixture. No worries for the EC regulation then.

I know this Engineer we deal with on some projects who’s been in the Led technology for decades. 
I have some silly questions that I ask him which starts by : “is it possible with Led to do this?”. When I am over optimistic he simply answers by: “With Led, everything is possible... if you can break the laws of Physics!”
225 lumen/watt is possible then... Maybe not just now.


Marc Galerne
Managing director of K5600 Lighting Europe.


Le 22 mai 2018 à 10:02, Peter Daffarn <peter@...> a écrit :

Hi Geoff,

Speaking for a manufacturer it is equally as hard to decide what to use as your output figures.
Short of listing every option possible which I suspect would be equally confusing there is no standard.
Naturally given this every manufacturer will choose to use the system that gives the best for their fixture.
Lumen output is not much use as that is simply how much light is produced - not how well it is projected to the subject.

In my humble opinion what is important to you guys is how much light you get on your subject at a certain distance.
The area that light covers is equally important as I have noticed some manufactures quoting huge output figures which only apply to the absolute centre of the beam.

I for one would welcome some standardisation on how to quote light output figures.


Regards


Peter Daffarn
Managing Director
Photon Beard
UK

Pete Challinger
 

Great post Marc, and right on the money.  Lugging HMI ballasts is a pain for everyone - but still a very necessary evil.  I think people want so much to believe the "our LED is as bright as an HMI" BS from some companies, that they just become totally gullible consumers.  Once they've bought the light of course then human nature is not to appear to be an idiot so they perpetuate the myth to others. 

I think as an industry we need to be less tolerant of people lying through their teeth!

Pete

Pete Challinger

VP US Operations for Photon Beard Ltd.

T: 530-267-0822 or 818-237-4257
M:530-200-0295


---- On Wed, 23 May 2018 14:16:39 -0700 Marc Galerne<marc@...> wrote ----

I agree with Peter.
As a manufacturer I totally agree that it’s difficult to get a standard. Since the arrival of Leds a lot of BS has been printed in brochures by ignorant or worse, dishonest manufacturers.

Adam Wilt
 

Lugging HMI ballasts is a pain for everyone - but still a very necessary evil.  I think people want so much to believe the "our LED is as bright as an HMI" BS from some companies, that they just become totally gullible consumers.

But it’s true: if you have enough LEDs to weigh as much as the HMI and its ballast, you can probably get the same amount of light out of them.

Adam Wilt
technical services: consulting / coding / camerawork
Vancouver WA USA (no, not that Vancouver, the other one)

Pete Challinger
 

OK Adam - I'll take the bait - can't resist!  It's another "seems like it should be true" thing.  We know HMIs can be heavy and the old magnetic ballasts weighed a ton and new LED lights are small and probably don't weigh much just looking at them.  Problem is when you pick those same LED lights up you find them surprisingly heavy because of the massive heatsinks needed.

Prodded me into a quick and very rough sanity check comparison.  Our 1200W HMI Blonde and Power Gems ballast weigh about 35 pounds.  Osram specs the bulb at 110,000 lumens.  The largest LED panel from a well know manufacturer claims total of 120,000 lumens so definitely brighter - but with the power supply included it weighs 115 pounds! 

Food for thought in trying to recalibrate what we think we "know"!

Pete Challinger

VP US Operations for Photon Beard Ltd.

T: 530-267-0822 or 818-237-4257
M:530-200-0295


---- On Wed, 23 May 2018 22:40:29 -0700 Adam Wilt<adam@...> wrote ----

But it’s true: if you have enough LEDs to weigh as much as the HMI and its ballast, you can probably get the same amount of light out of them.

Steven Gray
 

And with an hmi you can just change the build when the bulb blows.  How many led lights that we use today are going to be useful in say 5 years time, unless the manufacturers say that they will do a refit of the led panel.  I have a dedo 400 hmi that I bought more than 15 years ago.  Still going strong.


Steven Gray
Director of Photography
London
UK
07711 009515
stevengray31@...
DoP website: http://www.stevegraydop.com
Kit website:
http://www.barefootpictures.org
IMDB: http://www.imdb.com/name/nm1034732/
Vimeo: https://vimeo.com/stevengraydop


George Hupka
 

The other specs that need to be standardized are the distances... One manufacturer is at 2, 5, 10m.... The next is at 5, 10, 15 feet ...  No consistency whatsoever and much harder to try to extrapolate distances than to convert between footcandles and lumens...

--
----------
George Hupka
Director/DP
Saskatoon, Canada
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