Continues lightning question

[Anonomatos]

Hi there,

I've been researching lot's about LF recently and I have a question considering continues lightning (I don't really like flash when I'm composing my shot). I'll be shooting portraits in daylight.

There are always big and bulky (and power consuming solutions) as far as I've seen irl and on the net. I'm thinking of building a small and lightweight 'spot' which consists of a rechargable battery pack and 10 watts of Luxeon 5500k LEDs jammed in a small packed with a tripod mount. With my calculations it should last for half an hour or so on a single battery pack.

Any of you have experience on such a portable 'spot' (building and/or using)? Are there any downsides to continues light (compared to flash)? Any tips when working with continual light?

Thanks :)

*edit*
I've worked with reflection-screens (white and silver) but I'm looking for a constant light source, I don't want to be dependant on the sun or other people holding reflection-screens.

[Bob Salomon]

How will you ensure even coverage from edge to edge and ensure correct color temperature across the field?

[Anonomatos]

Well, 5500k is the basic temperature and a few warmer and cooler (6500k and 4000k) LEDs with adjustable levels will make the temperature exact. This way I can adjust the temperature exactly the way I want (nice for effects, and I won't need color filters for the lights). Though I need an external light-temp-meter.

And what do you mean by "even coverage from edge to edge"? The dividing of the light vs. a beam of light? Or something else?

[Bob Salomon]

Keep the amount of light on the edges the same as the center.
Kaiser makes a LED camera light that has 19 "white light" LEDs that give out about 15 Lux at 3m. It runs for at least 3 hours on 2 AA cells.

This is enough light for a point and shoot camera or a small VCR but no where near enough light to get a large format camera to f11 to 22!

The normal problems with continuous lighting (tungsten or quartz halogen) are:
1:heat
2:bulb life
3:color temperature
4:current draw
If you use professional quality flourescents (HF type) you get:
1:daylight or tungsten color balance, depending on the tubes
2:cool burning compared to tungsten or quartz
3:low current draw
4:long tube life

Until the eveness of the illumination and the output and the color temperature can match flash LED technology is not the answer. A good flash gives a range of outputs down to as low as 1/32. It may have constant flash duration and constant color temperature at all power settings. You get lots of flashes off a modern power pack, you can have dead accurate modeling lights, you get extremely long tube life. And you may have to carry 3KG of weight - including the battery pack - which is really not a lot!

And half an hour of shooting time is really very, very little with large format shooting!

Some very good, portable flash lighting is made near you in Cologne, right by the airport outside Porz or Ferdiand Porsche Strasse.

[Frank Petronio]

Movie makers need high output constant lighting that can overpower existing light... but those lights come in large trucks, requiring electricians and a crew.

You might want to try renting some HMI lights before you go too far.

[Bob Salomon]

[QUOTE=

You might want to try renting some HMI lights before you go too far.[/QUOTE]

Those are not the most portable either compared to flash. Or the lightest or the coolest operating.

[Drew Wiley]

I have never had an issue using old-fashioned Arri and Omni hot lights. You can do it
directly, like an old time movie, or diffuse the light through fabric or polyester sheets.
Color balancing with gels is easy, and the whole system is both portable and relatively
affordable. If color balance is really critical you can use a color temp meter and
correction filters, but this is seldom necessary. Maybe not the best setup for product
shots of ice cream. But for people you just use your assistant temporarily for a fill-in
before posing the subject under the light, or have the main subject relax a minute with
the light bank turned off before the final shots. This is how they did it for decades.
I really like the combination of hot lights and 8x10 film. The subject takes it seriously
and cooperates because they know you're doing it the old-fashioned "hard" way.
I've never even bought a flash system, though that might be nice for uncooperative
kids or something, in which case my own answer is a handheld Nikon instead. This
might not be the right approach for everyone, but I'm sure glad I didn't make things
any more complicated than necessary. The focussing Arri beam is especially versatile.

[jamesklowe]

..you're going to need a lot of kick to light your models at full daylight. You should work backwards, start with what kind of power source do you have? they draw alot of power, i'm not sure what houses are like over there, but you can run about 3 x 2k blondes off 1 house in new zealand (3 circuits, each circuit takes about 3k).

if you don't want to go daylight and shoot with tungsten film, PAR cans give alot of kick for just being 1k.

otherwise if it is daylight you're really after. HMI's are your best bet. downside is they usually charge for bulb time aswell.

all of this is not so portable unless you want to drag a generator around.

[Sideshow Bob]

Is this what you are thinking? Do a search for

1000 LED Video Studio Portrait Panel Light

on eBay. They also have a 500 LED light.

Gale

[jamesklowe]

LED brick lights don't give nearly as much kick as you think they will..

fantastic upclose. but don't bother for anything else. esp. in daylight

[Drew Wiley]

I apparently misunderstood. You are intending to shoot outdoors and need something
to replace fill flash? Or do you mean you are using natural window light and need to
supplement that? And if outdoors (implied by your mention of a battery), why can't you use small reflectors to target highlights? Maybe I'm naive, but sounds like a lot
of work for a simple problem.

[Anonomatos]

Yes, I'm working outdoors. Reflectors do work partly, and they are fine. But I'm looking for a light that works, even if the sun goes behind a cloud, to highlight a bit.

Big studio lights are too much light and it's outdoors, I don't have a wall-socket nearby.

It's just for a bit of highlighting. Maybe I'm just no good with reflector screens and just focus on learning that... But I'm always into alternatives :)

Am I being a bit clearer now?

[jamesklowe]

if you're only looking for just a bit of highlighting, a mirror would be perfect- assuming reflectors aren't giving you enough

[jp]

Some small flashes like a vivitar 284/285, Nikon sb24/sb800 et.al. with manual controls are frequently used with reflectors instead of studio flashes/monolights for outdoor use. The only downside is the slower recharge time and the need for lots of AA batteries. The recharge time shouldn't be an issue for LF use. There's a big internet community for people who do creative things with these sort of flashes.

[Anonomatos]

A mirror might be a good idea too. Anyways, this enough info for now. Thanks a bunch for all the reactions.

The next time I'll try to make myself a bit more clear. Expressing myself in English is still challenging for me! :)

Thanks again, this LF forum has lots of helpful people dwelling around!

[21tctrade]

Hi,thank you for posting this .Acturally I am wondering this too.So thank you for all the guys' replies

[domaz]

*edit*
I've worked with reflection-screens (white and silver) but I'm looking for a constant light source, I don't want to be dependant on the sun or other people holding reflection-screens.

10-watt- even with LEDs- is nothing outdoors in daylight. Replace all your 1-watt luxeon with the 5-watt models and maybe you could get somewhere with it. But then your costs go sky high along with current consumption and the cost for a suitable constant-current power supply. Still 50-watts of Luxeon LEDs would give you 1600 Lumens- about the same as a 100-watt bulb. Probably still not going to get you anywhere.

[mandoman7]

Continuous or tungsten lighting are the terms I'm familiar with.

Its fun to build things that are used for shooting, but I would suggest that you find a way to test your idea first. Earlier in my career I spent a lot of time trying to supplement existing light in portraits with various techniques and it almost always ended up looking artificial to my eye. Maybe that's what's desired in this case, I don't know. But, in general, multiple light sources will often create telling shadows.

This may not be the answer to your question, but I've found that for outdoor portraits where the sun is high, there's nothing better than a diffusion panel with the subject placed in front of a darker background somehow. This is the method in use by most movie and fashion shoots, I believe.