Question about watt-seconds and light output capability

[Alex Ethridge]

4 x 400 watt-second lights with standard reflectors, one in each corner pointing at the ceiling should do it.

I think that unlike almost everyone else who has commented here I under stand why you want a light in each corner and why you should place them slightly above head height and pointing at the ceiling. Also why you don’t to use anything that resembles a Profoto Magnum reflector.

You want near perfect backlight and fill no matter where you point the camera.

In the space you describe, at full power a 400 w-s per light in each corner will more than satisfy your iso and aperture scenario. You may even be be able to use the lights at lower power and use either a lower ISO or smaller f-stop.

How I know all of this? Because I’ve done it. It was a long time ago but it’s a set up that works.

Is it a set up that’s going to produce beautiful lighting with lots drama? No but I don’t think that is what you are after.

Thanks for the confirmation.

 

[Michael Fryd]

Let's say I wanted to light a room 30x30 (feet), off-white walls, white ten-foot ceilings, medium gray floor with 30 or so people milling about, dancing or whatever else, and I wanted to do it with four lights aimed at the walls or ceilings to give images a wide open, almost daylight look.

What WS rating on each light do you think will do it.

Yes, I know WS is input but that's the way they're rated (or were in the days of film). If power ratings are different in the digital age, please set me straight.

You seem to have had quite a lot of advice on this but I haven't seen anybody ask you an important question. Do you need mains or battery powered lights?

Mains lights are cheaper, can be more powerful (1200Ws or so), generally recycle quickly, and will keep going all night. However you do need to run cables to them and having one in each corner of a room pretty much guarantees that at least one of them will have a long cable run. In a room full of dancing people you will have to be very careful how you run the cables and some venues are rather touchy about having trip hazards.

Battery lights are considerably more expensive. Have limited power capacity (600Ws tops) and limited battery capacity (typically 300-400 full power pops). They have the advantage of being cable free and generally easier to transport and quicker to set up.

High power lights with fast recycle speeds may need to be on dedicated circuits or they may trip the circuit breakers. If you do go for such lights, look for ones that have an option for a slow recycle time, and make sure you know where the circuit breakers are for the room, so you can reset them.

When you are shooting on location, you may have trouble finding dedicated circuits for each light.

If you put a battery pack on each Einstein, and plug it in, you will have power all night, and the battery pack acts as a buffer, so the circuit breaker never sees that spike in power draw when the lights recharge. The problem with this method is that you get slow recharge (4.2 seconds at full power) and you should not use the modeling lights.

 

[Alex Ethridge]

...

I also have a Buff Digibee DB800 light unit which is 800 WS.

The DB800 is a good light, but has only 320Ws of power.

I'm a big fan of the Einstein lights. I think they are a good choice, and can be set for anywhere from 2.5Ws to 640Ws.

One nice thing about the Einsteins is that they are designed to be used with normal power. You should be able to plug two of them into the same circuit, and they shouldn't blow the breaker. Lights that recycle faster than the Einsteins draw more power when recycling, and are more likely to trip circuit breakers.

Having a background in electricity and wiring houses with my dad growing up, that is a concern. I was wondering how may amps these monolites draw on full surge. Also, I know some of the buildings I will work in will be old and the wiring not so great. I have a generator but the noise and long cables going outside scattered across the ground and floor make that a laughable solution.

If you need more power than 640Ws, I suspect you are better off with more lights, rather than higher power lights. More lights make it easier to get a more even distribution throughout the room.

Yes and lower-power lights on batteries solve the circuit breaker and wiring problems .

Buff sells a lithium battery/inverter system. With an Einstein at full power, it slows the recharge time down to about 4.3 seconds. You can put more than one Einstein on a battery pack, but I don't recommend it for event shooting,. Multiple lights per pack take even longer to recharge.

 

[Alex Ethridge]

Position your bare bulb lights without reflectors so that they are aimed at the corner where it meets the ceiling. Having them a couple of feet from the corner should be fine.

If you use light stands block them off to make sure that nobody can bump into them and knock them over.

Sandbags too.

If the ceiling is a drop ceiling then these are a much safer way to mount your lights. Kupro makes one with a longer pin.

Adorama - Alzo Digital Suspended Drop Ceiling Photo Video Light Mount Kit

Adorama - Kupo Baby Drop Ceiling Adapter with 5/8" Stud

You will not get even lighting and it will be top down lighting so you will have shadowed eye sockets.

You can walk around the venue with your flash meter just in front of your chin and take readings, and use pieces of different colors of tape to show you the different exposures.

Alternatively use a TTL flash on-camera and use Flash Exposure Compensation to turn the flash into a fill flash. You want to fill in the shadows in the eye sockets yet keep the surroundings fairly well exposed.

 

[Alex Ethridge]

Let's say I wanted to light a room 30x30 (feet), off-white walls, white ten-foot ceilings, medium gray floor with 30 or so people milling about, dancing or whatever else, and I wanted to do it with four lights aimed at the walls or ceilings to give images a wide open, almost daylight look.

What WS rating on each light do you think will do it.

Yes, I know WS is input but that's the way they're rated (or were in the days of film). If power ratings are different in the digital age, please set me straight.

You seem to have had quite a lot of advice on this but I haven't seen anybody ask you an important question. Do you need mains or battery powered lights?

Mains lights are cheaper, can be more powerful (1200Ws or so), generally recycle quickly, and will keep going all night. However you do need to run cables to them and having one in each corner of a room pretty much guarantees that at least one of them will have a long cable run. In a room full of dancing people you will have to be very careful how you run the cables and some venues are rather touchy about having trip hazards.

Battery lights are considerably more expensive. Have limited power capacity (600Ws tops) and limited battery capacity (typically 300-400 full power pops). They have the advantage of being cable free and generally easier to transport and quicker to set up.

After considering the liability of a lot of wires on the floor and the battery-operated units being well below 1000WS I am rethinking unit power and possibly quantity.

Also, I'm wondering if these battery-powered units can be charged while in use (when practical).

 

[Michael Fryd]

...

I also have a Buff Digibee DB800 light unit which is 800 WS.

The DB800 is a good light, but has only 320Ws of power.

I'm a big fan of the Einstein lights. I think they are a good choice, and can be set for anywhere from 2.5Ws to 640Ws.

One nice thing about the Einsteins is that they are designed to be used with normal power. You should be able to plug two of them into the same circuit, and they shouldn't blow the breaker. Lights that recycle faster than the Einsteins draw more power when recycling, and are more likely to trip circuit breakers.

Having a background in electricity and wiring houses with my dad growing up, that is a concern. I was wondering how may amps these monolites draw on full surge. Also, I know some of the buildings I will work in will be old and the wiring not so great. I have a generator but the noise and long cables going outside scattered across the ground and floor make that a laughable solution.

A monolight like the Einstein can have a peak draw of over 18 amps while recharging. This peak lasts for under a second.

With two Einsteins the peak can top 36 amps (about 4.3 KiloWatts). However the duration is short enough that if that's the only load, it wont trip a typical circuit breaker (they can tolerate a short peak that is a bit more than their rated trip current).

The problem with running a monolight on a generator or battery inverter is that typically don't have power to meet that peak load.

Running a monolight on some battery inverters or generators can be problematic, as they give up when they see the peak load.

To make things even more challenging, many monolights (including the Einsteins) really need pure sine wave power. Many inexpensive inverters put out an approximated sine wave,

Buff addresses this problem with a two pronged approach. His Vagabond battery inverters are current limited. Put a momentary overload on them, and they maintain pure sine wave output, but the voltage drops. If the overload is high, the output could drop to as low as 60VAC. The key is that they don't shut off, they simply reduce voltage.

Buff's lights are designed to work at these lower voltages. However, as the voltage drops, they recharge more slowly, placing less of a peak demand on the inverter.

Plug one Einstein into a Vagabond Mini, and it can fully recharge in 4.3 seconds. Plug two into the same Vagabond Mini, and a full recharge may take almost twice that. That's impressive as the Vagabond Mini is rated for a maximum 120W continuous load (slightly more peak load)

If you need more power than 640Ws, I suspect you are better off with more lights, rather than higher power lights. More lights make it easier to get a more even distribution throughout the room.

Yes and lower-power lights on batteries solve the circuit breaker and wiring problems .

But limit you to how many shots you can take before you need to swap in fresh batteries.

You need to figure out which is the best compromise for your situation.

Buff sells a lithium battery/inverter system. With an Einstein at full power, it slows the recharge time down to about 4.3 seconds. You can put more than one Einstein on a battery pack, but I don't recommend it for event shooting,. Multiple lights per pack take even longer to recharge.

 

[tugwilson]

After considering the liability of a lot of wires on the floor and the battery-operated units being well below 1000WS I am rethinking unit power and possibly quantity.

Also, I'm wondering if these battery-powered units can be charged while in use (when practical).

I have Godox AD600Pro and AD400Pro lights. Both will run off battery (~350 full power pops) or from mains. Neither will trickle charge the battery on the light. If you are able to run cables to the lights you are far better off using the mains power unit than trickle charging.

The non Pro AD600 (older version) has a remote head that allows you to connect two of the units to give you 1200Ws. Firstly I don't think you will need 1200Ws and secondly for your application you should be able to use two light pointing at an angle if you do.

I have a mild preference for the AD400Pro over the AD600Pro as it's lighter and so easier to transport. The downside is that it doesn't (yet) support a remote head. The AD600Pro remote head is useful because you can use a lighter stand and put the body of the AD600Pro at the bottom of the stand instead of having to use a sandbag.

In the US Adorama is the preferred vendor of Godox kit which they rebrand as Flashpoint.

 

[flyinglentris]

Let's say I wanted to light a room 30x30 (feet), off-white walls, white ten-foot ceilings, medium gray floor with 30 or so people milling about, dancing or whatever else, and I wanted to do it with four lights aimed at the walls or ceilings to give images a wide open, almost daylight look.

What WS rating on each light do you think will do it.

Yes, I know WS is input but that's the way they're rated (or were in the days of film). If power ratings are different in the digital age, please set me straight.

You seem to have had quite a lot of advice on this but I haven't seen anybody ask you an important question. Do you need mains or battery powered lights?

Mains lights are cheaper, can be more powerful (1200Ws or so), generally recycle quickly, and will keep going all night. However you do need to run cables to them and having one in each corner of a room pretty much guarantees that at least one of them will have a long cable run. In a room full of dancing people you will have to be very careful how you run the cables and some venues are rather touchy about having trip hazards.

Battery lights are considerably more expensive. Have limited power capacity (600Ws tops) and limited battery capacity (typically 300-400 full power pops). They have the advantage of being cable free and generally easier to transport and quicker to set up.

After considering the liability of a lot of wires on the floor and the battery-operated units being well below 1000WS I am rethinking unit power and possibly quantity.

Also, I'm wondering if these battery-powered units can be charged while in use (when practical).

When you posted that you had decided to go with 1000 WS units, I kind of figured that after other members had time to post responses that you would reconsider for units in the 500 WS range.

For what you propose, I would take a look at bank lighting as yet another way to use multiple light units.

My Buff Mini-Vagabond Lithium Battery Pack can be recharged while actively in use. You don't need to own Buff lighting units to use a Buff Mini-Vagabond. They are not vendor specific and simply provide two plug outlets into which you can plug in anything, hopefully with low enough amperage that they don't get drained quick, including cameras, LCD monitors, monolights and laptops.

BTW: Somebody posted not to use Modelling Light with Buff units. That's not exactly best advise. It's too total. You use modelling lights briefly to ascertain a visual clue as to your lighting setup effects. Then switch them off. They do not necessarily produce the highest output that Flash in the same units will produce. You can however use them as a source of continuous lighting. Exposure settings can be adapted, even with the lower output of modelling lights. But ... don't use them as continuous lighting off battery packs, don't use them that way when using lighting filters that can be damaged by the heat generated by the lights and don't use them that way when the lights can irritate your subjects and cause them to squint.

--
"If you are among those who believe that it has all been done already and nothing new can be achieved, you've murdered your own artistry before ever letting it live. You abort it in its fetal state. There is much that has yet to be spoken in art and composition and it grows with the passage of time. Evolving technologies, world environments and ideologies all drive change in thoughts, passion and expression. There is no way that it can all ever be done already. And therein lies the venue for the creative artist, a venue that is as diverse as the universe is unmapped and unexplored." - Quote from FlyingLentris
~
flyinglentris in LLOMA

 

[Michael Fryd]

....

When you posted that you had decided to go with 1000 WS units, I kind of figured that after other members had time to post responses that you would reconsider for units in the 500 WS range.

For what you propose, I would take a look at bank lighting as yet another way to use multiple light units.

My Buff Mini-Vagabond Lithium Battery Pack can be recharged while actively in use. You don't need to own Buff lighting units to use a Buff Mini-Vagabond. They are not vendor specific and simply provide two plug outlets into which you can plug in anything, hopefully with low enough amperage that they don't get drained quick, including cameras, LCD monitors, monolights and laptops.

You shouldn't assume that any monolight will work with the Vagabond.

Buff's Vagabond Mini is current limited. It lowers voltage (but maintains pure sine wave output) when presented with a heavy load (such as a monolight recycling).

While the Vagabond is not vendor-specific, not all monolights will tolerate the lower voltage, and therefore the Vagabond Mini is not compatible with all lights.

BTW: Somebody posted not to use Modelling Light with Buff units. That's not exactly best advise. It's too total. You use modelling lights briefly to ascertain a visual clue as to your lighting setup effects. Then switch them off. They do not necessarily produce the highest output that Flash in the same units will produce. You can however use them as a source of continuous lighting. Exposure settings can be adapted, even with the lower output of modelling lights. But ... don't use them as continuous lighting off battery packs, don't use them that way when using lighting filters that can be damaged by the heat generated by the lights and don't use them that way when the lights can irritate your subjects and cause them to squint.

While Modeling Lights are a good thing, I suggest that you don't use them with a battery pack.

The Einstein's standard modeling light is 250W. That alone is twice what the Vagabond mini can power. The LED modeling light on the DigiBee is brighter, but still uses 75W of power.

A 75W continuous modeling light uses as much battery power as flashing a 640 Ws strobe every 8.5 seconds. That will deplete the battery in a Vagabond Mini in about an hour an and 10 minutes, without ever using the flash.

So while I do like using modeling lights, I don't recommend you use them when on battery power. Furthermore, if you are worried about blowing fuses, it can help to keep them off. On an Einstein the modeling light can add 2 amps of continuous current draw.

====

If you are looking for continuous lighting the DigiBess has an LED that puts out as much light as a traditional 400W bulb, but uses only 75W of power.

However, if you are only looking for continuous light, then there are some low cost light panels out there that put out more light than the DigiBee, at a lower price point.

I would not suggest continuous lighting for an event like a wedding reception. Continuous lighting will interfere with the mood of the room lighting.

 

[BAK]

I'm not sure how many 1000 WS flash units there are with TTL, but I do know ProFoto has one, at least, and ProFoto has a fairly small camera-top-style round head flash with TTL that can also act as a trigger for the big monolights.

BUT... there are not a lot of wedding photographers who try to illuminate the entire room with each shot.

There must be a reason, other than needing a lot of expensive lights.

Think about the old fashioned way.

FORMALS: Set up a couple of monolights and bring over the people you want in group shots. Have a mirror so people can check their hair, spinach in their teeth, neckties, etc.

CANDIDS: Put a TTL monolight like a Godox 400 on a light stand with a small umbrella and light stand.

Carry this around in your left hand. Put it down when you want to take a picture.

Put a little flash in a wedding bracket attached to your camera. Use this for fill. A Godox V1 would be a good choice. Experiment and decide if you want to on TTL or not.

BACKGROUND: You can point another monolight or V1 at some part of the background, and turn it on or off with the V1 controls.

BAK

 

[tugwilson]

I'm not sure how many 1000 WS flash units there are with TTL, but I do know ProFoto has one, at least, and ProFoto has a fairly small camera-top-style round head flash with TTL that can also act as a trigger for the big monolights.

BUT... there are not a lot of wedding photographers who try to illuminate the entire room with each shot.

There must be a reason, other than needing a lot of expensive lights.

Think about the old fashioned way.

FORMALS: Set up a couple of monolights and bring over the people you want in group shots. Have a mirror so people can check their hair, spinach in their teeth, neckties, etc.

CANDIDS: Put a TTL monolight like a Godox 400 on a light stand with a small umbrella and light stand.

Carry this around in your left hand. Put it down when you want to take a picture.

Put a little flash in a wedding bracket attached to your camera. Use this for fill. A Godox V1 would be a good choice. Experiment and decide if you want to on TTL or not.

BACKGROUND: You can point another monolight or V1 at some part of the background, and turn it on or off with the V1 controls.

You might find this Robert Hall video useful. He starts talking about lights about half way through.

 

[Alex Ethridge]

I'm not sure how many 1000 WS flash units there are with TTL,

I may have to back down on 1000ws as I don't want the liability of cables running in places where someone might trip and fall. So I will be exploring 500-600ws TTL units or whatever I can put together in the battery-powered TTL units in the sub 1000ws range.

but I do know ProFoto has one, at least, and ProFoto has a fairly small camera-top-style round head flash with TTL that can also act as a trigger for the big monolights.

Yes, I've seen that unit, or at least one similar.

BUT... there are not a lot of wedding photographers who try to illuminate the entire room with each shot.

There must be a reason, other than needing a lot of expensive lights.

Think about the old fashioned way.

FORMALS: Set up a couple of monolights and bring over the people you want in group shots. Have a mirror so people can check their hair, spinach in their teeth, neckties, etc.

In the days of film, I used small, portable umbrellas and here's the problem with those smaller lights. They have to be placed too close to the group and in many groups the distance is ten feet or more across. The light fall-off from nearest to furthest can be two or three stops. If a more much powerful monolite is placed further away and bounced off a wall, the law of inverse square works in my favor and the nearest and furthest subject are more evenly lit as the distance to the nearest is greatly increased.

CANDIDS: Put a TTL monolight like a Godox 400 on a light stand with a small umbrella and light stand.

If I have four monolites and can remotely turn off one or two that are behind me, I can use an on-camera light as a fill and the remaining two monolites can open the room and maybe even serve as rim or accent lighting.

Carry this around in your left hand. Put it down when you want to take a picture.

Can't move fast enough at a reception for this, and I would be restricted as to where I could put it down for fear of someone stumbling over it.

Put a little flash in a wedding bracket attached to your camera. Use this for fill. A Godox V1 would be a good choice. Experiment and decide if you want to on TTL or not.

BACKGROUND: You can point another monolight or V1 at some part of the background, and turn it on or off with the V1 controls.

BAK

 

[tugwilson]

If I have four monolites and can remotely turn off one or two that are behind me, I can use an on-camera light as a fill and the remaining two monolites can open the room and maybe even serve as rim or accent lighting.

If you want to do that then each strobe must be in a different group. Does your camera support 4 TTL groups?

 

[Alex Ethridge]

If I have four monolites and can remotely turn off one or two that are behind me, I can use an on-camera light as a fill and the remaining two monolites can open the room and maybe even serve as rim or accent lighting.

If you want to do that then each strobe must be in a different group. Does your camera support 4 TTL groups?

If I'm correct, it is not the camera that supports groups, it is the remote trigger.

 

[tugwilson]

If I have four monolites and can remotely turn off one or two that are behind me, I can use an on-camera light as a fill and the remaining two monolites can open the room and maybe even serve as rim or accent lighting.

If you want to do that then each strobe must be in a different group. Does your camera support 4 TTL groups?

If I'm correct, it is not the camera that supports groups, it is the remote trigger.

The camera determines the number of TTL groups supported. The trigger and the strobes determine the total number of TTL and manual groups supported.

For example, Nikon cameras support 3 TTL groups whereas modern Canon cameras support 5.

 

[Alex Ethridge]

If I have four monolites and can remotely turn off one or two that are behind me, I can use an on-camera light as a fill and the remaining two monolites can open the room and maybe even serve as rim or accent lighting.

If you want to do that then each strobe must be in a different group. Does your camera support 4 TTL groups?

If I'm correct, it is not the camera that supports groups, it is the remote trigger.

The camera determines the number of TTL groups supported. The trigger and the strobes determine the total number of TTL and manual groups supported.

For example, Nikon cameras support 3 TTL groups whereas modern Canon cameras support 5.

That is a new thing for me; I'll have to explore some and get a better understanding of how those interact.

 

[tugwilson]

That is a new thing for me; I'll have to explore some and get a better understanding of how those interact.

As I understand it, the camera does a test firing of each TTL group separately and meters each one. It then uses a magic formula to calculate the settings for each group to get the "right" exposure.

The latest Godox triggers have a TCM (TTL Convert to Manual) function that remembers the last TTL power settings for each group and then sets them to manual with this power settings. I use it as a quick and dirty way of getting approximately the right levels when I'm in a hurry.

 

[Rico Tudor]

After considering the liability of a lot of wires on the floor and the battery-operated units being well below 1000WS I am rethinking unit power and possibly quantity.

Also, I'm wondering if these battery-powered units can be charged while in use (when practical).

You can pick up a Profoto Pro-7B pack and head for a few hundred dollars all day on eBay. That gives you 1200Ws, battery operation, 2-sec full recharge, and 300 pops at full power. I use the more upscale Pro-B2 with inbuilt radio trigger. The companion Profoto AcuteB pack is cheaper, lighter and gives 600Ws (I have one of those, too). And, yes, they can be recharged while in use.

 

[Sailor Blue]

Position your bare bulb lights without reflectors so that they are aimed at the corner where it meets the ceiling. Having them a couple of feet from the corner should be fine.

If you use light stands block them off to make sure that nobody can bump into them and knock them over.

If the ceiling is a drop ceiling then these are a much safer way to mount your lights. Kupro makes one with a longer pin.

Adorama - Alzo Digital Suspended Drop Ceiling Photo Video Light Mount Kit

Adorama - Kupo Baby Drop Ceiling Adapter with 5/8" Stud

One important addition to this.

Safety is paramount.

If you use a drop ceiling adapter be sure to also use a safety lanyard with your strobe. The last thing you want is for a drop ceiling bracket to give way and the light to fall on someone.

If you run extension cords be sure to tape them to the floor or walls. Use gaffer's tape so you can remove it without leaving a residue of adhesive. Gaffer's tape is very strong so be careful not to pull the paint off the walls when removing the tape.

B&H - Impact Gaffer Tape (Black, 2" x 55 yd) GT10-255B B&H Photo

As for the power needed, you need enough to bring up the room lighting to allow you to shoot the environment at a reasonable ISO and aperture. That is about all you can say until you get there, set up your lights, and try them out.

You will still want an on-camera flash to act as a fill light on the subjects.

If my memory is right Will Crockett did a video on this very subject years ago, but I can't find a link to it. Chances are that it is no longer available. Perhaps someone else knows if there is a link somewhere.

 

[SmilerGrogan]

If you dig a little bit you can generally find the output specs listed in f/stops for a particular distance. Then use appropriate rules of thumb to get an idea of what you need. For instance bouncing off a white wall might cost 1 to 1.5 stops.

As far as needed power, companies usually list the amp draw as well, and as long as you figure in a safety factor (sorry, my reference books aren’t with me) you won’t burn the place down.

Below, for instance the chart for Buff’s plain Jane 7-inch reflector with various moonlights.

Also, if you want light that brings out shapes a little better try a triangular light arrangement—In his book “matters of light and depth” Ross Lowell recommends placing lights in the corners along one wall and then one light in the middle of the opposite wall.