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Gary Moses February 19th, 2008 03:17 PM

Bill, I must agree the LEDS are lighter and more compact. I have also been using 27watt cfl's in a 9 socket fixture that is about 8 inches square by 6 inches deep. Each one puts out about 900 watts (equivalent) daylight balanced. I find myself shooting daylight balanced all of the time and converting them with a full CTO when I have to mix. What a strange trip it has been.
Gary

Mark Sasahara February 19th, 2008 09:43 PM

LED's are not all perfect. Some still suffer from color spectrum spikeyness, giving it a funky color. Probably more noticeable on film, than on video. Some of the LED's have color fringing at closer distances. I have a couple of Lightpanels, that don't fringe, but I saw the Zylight and that fringes, though after a couple of feet the beam smooths out.

Fluoros, like Kinos are great and seamlessly match tungsten to tungsten and daylight to daylight.

Manufacturers make a lot of claims, but your light meter and monitor will tell you what the truth is. It's always best to test. Go to the store, or rental house with your meter and monitor and see. Be sure that you turn off any other lights or shade the meter from other lights.

See if you can get a photometrics table from the manufacturer. That should at least put you in the ballpark as far as comparing different fixtures, or estimating what the output is. Use the footcandle measurements that the manufacturers give and then base your exposure on that. The ASC book has a table where you can get your f stop depending on the ISO (of your chip). I think the Panavision website has tables as well.

Richard Andrewski February 20th, 2008 05:24 AM

Quote:

Originally Posted by Gary Moses (Post 828882)
Richard, I've included (attached) 2 versions that I use. The 5 led I keep in my camera bag and the 11 led I use to support my main lighting package. You can switch on either 1 or all 5 leds on the 5 and you can switch on 5 or all 11 leds on the 11.
According to cree, each led puts out 50 lumens, that would be 150 per mr-16 and 1650 for all 11, probably equivilent to a 100 watt bulb.
The strange thing is that output is pretty strong and beam width is somewhere between a tungston and a fluorescent. The power is quite remarkable. I have used the smaller version (in a pinch) in a restaurant to shoot a German Band. At 15 or 20 feet is was strong enough to change the white balance to daylight. Is it possible that the camera sees much more led output than we do?
Gary

Very nice. So can you tell us the total cost to make the 5 and 11 models? Also did you incorporate a dimmer? And are these 110v models or 12v model LEDs? If they're 110v I guess the answer to the dimmer question would be no for sure as that pretty much makes it impossible to dim them. One other explanation may actually be the spot lens and reflectors on these types of LEDs which may be so efficient that it makes up for any lack in real lumens per watt.

Gary Moses February 20th, 2008 08:23 AM

Richard,
It looks like it cost $214.90 for the 11 cree mr-16 or about $19.54 each, by the way they are regulated so they have a little more weight (and cost) then non-regulated. The project boxes are from Radio Shack and they are $4 to $5 each. They operate 12 volt dc and I wired then in parallel using a double pull single throw switch to control the amount of lights to be illiminated. For example, I can use either 1 led or all 5, or 5 leds or all 11 on the 11 unit. I have never been a fan of dimmers on dc or ac, by using the switching method and diffusion (hardly ever needed) I can keep the color and brightness constant.
As far as power sources, obviously 12 volt batteries, extentions from my car and 12 volt converters. (Radio shack has a great little 1amp unit that powers in a pinch) and of course 4 and 6 amp transformless converters. I prefer to have a variety of power choices than to mount the converter internally.
Gary

Gary Moses February 26th, 2008 08:19 AM

It appears that the cost of the crees 1 watt have decreased.

Leo Versola February 26th, 2008 01:46 PM

Quote:

Originally Posted by Gary Moses (Post 833255)
It appears that the cost of the crees 1 watt have decreased.

Gary,

Where have you found to be the best source(s) to buy these lights?

Thanks,

Gary Moses February 27th, 2008 08:08 AM

Leo, here are 2 of the sources that I have bought bulbs from. They both have excellent service attitudes and will work with you.
LedBulb has the crees and lumiamarketing was only carrying the Prolights.
Since my last purchase cree has come out with a 3 and 4 watt version and a 5 watt is either just out or about to be. My point being that since they have introduced the 3 and 4 watt version the 1 watts have dropped in price.
The higher wattage will introduce heat and draws substantial amperage.
Gary

Sam Wood
Lighting Consultant
LEDBulb.Bizz
Irvine, CA 92603
(949) 725-0917 phone/fax
(949) 285-6628 cell
Email: LedMania@gmail.com
http://stores.ebay.com/LEDBulb-Bizz
MSN: sgwd@hotmail.com
Skype: unitedmem

Julian Picman
Phone 613 796 2924
Fax 613 822 7293
lumiamarketing@yahoo.ca
www.LumiaBulbs.com


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