Comparing brightness of lights

[combatentropy]

How do y'all compare the brightness among lights when you're shopping? There seems to be inconsistency in units in their reported specs.

One light was in lumens. It would be straightforward if they all just used lumens.

But then I saw a bunch in lux, each at different distances. One was lux at 1 meter, another at 2 meters, another at 3, and one at 0.5. I guess I could do the math, if I knew the math.

Maybe some of you just go by watts, because it's close enough if they're all LED. But there are different types of LEDs (SMD, COB, etc.), some more efficient than others. For example, I used to hear that LEDs were roughly 4 times as bright as tungsten, now I'm hearing 6.

And when they happen to use the same unit (like lux at 1 meter), the difference so great that I wonder if there is a mistake. This new Nanlight FS-200 has a surprisingly high output, 4 times as much as another random LED I looked at, the Aputure LS300X, and the Aputure uses 50% more watts!

 

[Guest]

LED lights have varying degree of Watt to lumen ratios. Typically the new lights doing better. Nanlite is generally on the brighter and more accurate end of LED tech, likely because of their part of a huge LED lighting company, and don't just make cine lights, so they have the technical and financial might behind what they do.

The nnlite FS200 looks like it is using smaller LED "diodes" with lensless on them, so the throw is going to be far more intense compare to a true COB light.


Aputure may have the best fresnel and reflectors, as their COB lights are not the brightest when "bare bulb", but when a modifier is attached, they can turn around and catch up or beat most competitors with similar attachments. Nanlite seems to be releasing new products fast, and there are so many brands in the LED lighting space, so the scene is constantly changing. The amount of booths at trade shows in 2019 that were dedicated to LED lighting was astonishing.

The Lux and lumen ratings are only as accurate as the modifier used in that rating. It is generally assumed that the measurement is done with the base reflector attached.


The 120D and 120Dii have different brightness output because aputure improve the COB efficiency and the modifier's shape to push more light forward.


LED is a bit of a wild Wild West, testing is unfortunately the only way to know for sure. Luckily there are YouTube gaffers that do test all of these things and that helps speed up the process. So many variables surround LED lights, from how they are controlled to what kinds of colors they can put out, at the end of the day it comes down to personal preference and how you like to work and what you need to accomplish.

I could have gone with two 300w COB lights for the same price as the 500w, but didn't want to be moving two lights around whenever I needed more power, so having one light that can go from 0-100% simplifies my day. I really hate that I keep promoting the Forza500, it is not my intention. And I'll be honest, if the Aputure 600D was out, I might have likely gone with that. I mean, the Aputure includes a free v-mount charger! c'mon, that is cool! (although, I have really started to like the Nanlite control unit, it actually works well so far, and I dislike going back to other style units)

 

[puredrifting]

I must be shooting conservatively these days because I am mainly using one of VL300s as a key source these days for interviews and presentations and I am typically at 45% output or less.

I've always been, by necessity, but it also ended up being my style to use lots of smaller instruments versus 2-3 big instruments. Largely because I didn't have a generator available to power
large instruments but also because I love nothing more than having a lot of time to light a set with lots of interesting little nooks and cranies where I can do sofit lighting, back light things and highlight specific
items or features using small instruments with tight cuts like an Arri 300 or Dedos.

I love large lights punched through a 6x6 or an 8x8 for talent, or book lights but all of that stuff behind talent, man I like lighting it all up in little individual zones with smaller instruments, it gives you a look and feel that you just cannot
achieve with the wash from large sources. Cinefoil is the best for making fun little flags and snoots that you can hide in your backgrounds.

I shot a bunch of scenes for Disney where we got access to the Disney prop house and they brought over a whole truckload of beautiful and fantastical props from various live action Disney films over the years and a lot of Imagnineer relics.
It was a once in a lifetime opportunity, so I went nuts and spent a week lighting up one set to look like a toymaker/collectors workshop and I ended up using about 78 instruments. I lit all myself and it came out great, most of it was used in
a Peter Pan/Tinkerbell documentary and it was probably the most fun I ever had lighting anything. No crew, other than the art director and I was able to really look at the whole scene and light it exactly how I saw it in
my minds eye, a rare opportunity these days, especially when you don't shoot narrative.

 

[Guest]

I must be shooting conservatively these days

The Forza 500 lamp head is small and it dims down nicely for soft box use up in closer when needed. My main reason for going with 500watts was so that I only need to have one light. Of course I have a smattering of small lights like the 60w cob and quasar tubes, and couple odds and ends, string lights and xmas lights etc. But for the most part, I can got out the door with just the 500w and a couple gels and never get stuck in a bind. Anything more complicated and I'll hopefully work with another crew member. It can be easy to overlight, gotta watch the eyes of talent etc. They're the ones that have to look at it. But it also mean that the 500w will never have trouble getting through multiple bounce and layers of diffusion... which in the end are easier on the eyes for the talent.

But when I was doing local news, I had a cheap Ebay 1x1 light nursing V-mount brick, and was able to shoot about anything I really needed. So, yeah, totally agree with you, don't need much.

not my best work on display, but is still cool what a cheap little early days 1x led panel can do. I think the original Litepanel 1x1 was brighter. (one of those was like no light, and another may have been that lower tungsten soft box thing that was popular years ago)

 

[ozmorphasis]

I must be shooting conservatively these days because I am mainly using one of VL300s as a key source these days for interviews and presentations and I am typically at 45% output or less.

I've always been, by necessity, but it also ended up being my style to use lots of smaller instruments versus 2-3 big instruments. Largely because I didn't have a generator available to power
large instruments but also because I love nothing more than having a lot of time to light a set with lots of interesting little nooks and cranies where I can do sofit lighting, back light things and highlight specific
items or features using small instruments with tight cuts like an Arri 300 or Dedos.

I love large lights punched through a 6x6 or an 8x8 for talent, or book lights but all of that stuff behind talent, man I like lighting it all up in little individual zones with smaller instruments, it gives you a look and feel that you just cannot
achieve with the wash from large sources. Cinefoil is the best for making fun little flags and snoots that you can hide in your backgrounds.

I shot a bunch of scenes for Disney where we got access to the Disney prop house and they brought over a whole truckload of beautiful and fantastical props from various live action Disney films over the years and a lot of Imagnineer relics.
It was a once in a lifetime opportunity, so I went nuts and spent a week lighting up one set to look like a toymaker/collectors workshop and I ended up using about 78 instruments. I lit all myself and it came out great, most of it was used in
a Peter Pan/Tinkerbell documentary and it was probably the most fun I ever had lighting anything. No crew, other than the art director and I was able to really look at the whole scene and light it exactly how I saw it in
my minds eye, a rare opportunity these days, especially when you don't shoot narrative.

Wow, that's pretty cool Dan. Do you happen to have some frames that you can share from that?

 

[puredrifting]

Wow, that's pretty cool Dan. Do you happen to have some frames that you can share from that?

So long ago. I may have the DVD stuffed away somewhere that I could get some frames from? It's from when I was with a production company
so I never had masters (since it was studio stuff, all master were vaulted) but I usually tried to get a copy of the DVD or later the Bluray. I bet I
shot it with the original Varicam in 720p? Or it might have been NTSC with the DVX100B, I can't recall it was so long ago.

 

[Grug]

You’ve got to find photometrics at comparable beam angles and distances to get any clear picture of comparative output.

A really important measurement for me personally, is the comparative “volume” a light puts out, and this you can only really test by having the lights physically on hand. By bouncing the lights (off a large fabric or ceiling), and taking a meter reading from that broad and dispersed beam, you get a real sense of how much light a particular source can really put out to lift the general ambience of a room. It takes beam angles and modifiers out of the equation, and lets you know how useful each source is for fighting the sun (with lifted ambient level).

This is a really important measure to know, when you have to shoot a sequence of shots in a space and consistency between shots becomes really important; rather than just a single hero shot (like an interview angle) where you have much more leeway to focus all of your lighting firepower in one place.

 

[John Brawley]

How do y'all compare the brightness among lights when you're shopping? There seems to be inconsistency in units in their reported specs.

One light was in lumens. It would be straightforward if they all just used lumens.

But then I saw a bunch in lux, each at different distances. One was lux at 1 meter, another at 2 meters, another at 3, and one at 0.5. I guess I could do the math, if I knew the math.

Maybe some of you just go by watts, because it's close enough if they're all LED. But there are different types of LEDs (SMD, COB, etc.), some more efficient than others. For example, I used to hear that LEDs were roughly 4 times as bright as tungsten, now I'm hearing 6.

And when they happen to use the same unit (like lux at 1 meter), the difference so great that I wonder if there is a mistake. This new Nanlight FS-200 has a surprisingly high output, 4 times as much as another random LED I looked at, the Aputure LS300X, and the Aputure uses 50% more watts!

Number 1, with lighting it's hard to believe what any of them say, because they're all very inconsistent. They often lie. Or at best come up with bewildering number that you can never hit in real life. Best way of course is to measure.

Foot-candles / Lux at a given distance is the usual way.

You need to be aware to that the beam spread can greatly affect this. Typically many will talk about the beam as being once the brightness at the beam edge falls to less than 50% of the peak value in the middle of the beam. Thus you have the beam diameter. But LED's being a frustratingly soft light source typically make that hard to measure for say a panel. And that's why you often see the different distances quotes with FC / LUX

pCAM Pro has some useful calculations for working out FC into exposure. I use that a lot if I want to know how many fc I need for a given ISO / Aperture / Shutter speed combination.

There's also references you can look up to known photometrics of common lamps, but I've found them to vary wildly from the truth.

So for example using an App called "photometrics" tells me that a Par64VNSP lamp at 1000W and at a distance of 12 feet will give me 2778fc which is F32 3/4 on an Alexa at 24 fps and a beam width of 2 feet, also the same FC your nanlite can do, but at only 3 feet. Or if I fit the same lamp as a wide version, the Par64 WFL at the same distance is 278FC which would be F11 1/2 but with a 10 foot wide beam.

That won't take into account the brand of the lamp, the fixture etc. So it's all ball park....And those tables in apps like that typically can't keep up with the gazillion generic LED crap that is being churned out either. Plus a lot of those can vary from copy to copy, especially in spectral output.

Basically you have to almost do your own measurements with the lamps you like as you use them and then you can start to plan for when you're trying to light a stage / scene...

I realise you're trying to assess for purchase....but other than testing them out in a working environment it's hard to believe half of what is claimed usually....

Watts is pretty misleading other than in big picture terms. It doesn't talk to the efficiency of the light engine, the luminary design itself, (reflectors in the fixture or the design of the optics) and of course once you start adding lighting modifiers everything goes out the window.

JB

 

[combatentropy]

Thanks to everyone, so far. And puredrifting, I'm sorry, you're going to have to dig out that DVD

So, it sounds like you have to test these lights yourself, is the consensus. Do you test them in the store, or are the ones you're interested in usually available at your local rental house?

Actually I am not getting ready to buy anything. The thread on Black Friday specials took a dive into lighting, and it got me curious.

 

[John Brawley]

Thanks to everyone, so far. And puredrifting, I'm sorry, you're going to have to dig out that DVD

So, it sounds like you have to test these lights yourself, is the consensus. Do you test them in the store, or are the ones you're interested in usually available at your local rental house?

Actually I am not getting ready to buy anything. The thread on Black Friday specials took a dive into lighting, and it got me curious.

I’m always amazed at how willing vendors are to let you test. I ask all the time if I want to try something out. You can go direct to a re-seller who often have demo units, or you can go to the manufacturer or local / intra-country distributor. They will often have demo stock as well.

JB

 

[paulears]

Being old, photometrics has always been a general comparison, and a guide. The snags real are to do with, as been said, how light is produced, travels and ‘lands’. Over the years manufacturers have tried all sorts of ways to quantify light. Optics not just the light source are critical for comparison. It’s not just LEDs it’s been the same with arc, then tungsten, then modern discharge. We pick lights for their even field, or a variable field, or ones that have hard edges, or like Fresnels, stay bright then gradually drop off, or the modern micro lens Fresnels that don’t do this anywhere near as nicely. Measuring the actual brightness of the light source produces totally different results to what happens after reflectors, lenses, diffusion and distance have played their part. Hence I suppose why on film sets, people still put a light meter at the important place and measure that, not what generally goes in that direction. We even have some people measuring reflectance from surfaces. I’ve been thinking about trying to compare my light sources old and new, but I really don’t actually know how to provide a meaningful result. I sell a few lights and would like to be able to compare them, but often measurements look wrong. If you take a simple light like a redhead as you spot it, levels ramp up amazingly, but sometimes the wide angle is the most use, but a slightly narrower beam angle on paper looks so much brighter. Putting a brightish LED in an old linear Mole has totally changed it. So much so it’s pointless giving a brightness figure. I’ve got some daylight and variable CT panels and when I get a chance I’m going to compare the brightness. I think there is a big difference because realistically at the extremes onl6 half the LEDs are on, but I can’t quite work out what happens in the middle when they are both on, or is there some scaling applied? A light meter should reveal this. However, how does my light meter respond to different versions of white? I really don’t know.