Where to get high frequency flourescent ballast? (DIY Home made Kino Flo question) - Page 3 at DVinfo.net

Go Back   DV Info Net > The Tools of DV and HD Production > Photon Management

Photon Management
Shine an ever-loving light on you.


Reply
 
Thread Tools Search this Thread
Old October 4th, 2006, 11:13 PM   #31
Inner Circle
 
Join Date: Feb 2006
Location: Los Angeles, California
Posts: 2,069
Reply

Hi Jose, I mean Joseph, I mean Joe:

I think I keep writing Jason because he seems more like a Jason than a Jaron.

No, actually because I type in a hurry and don't proof well enough. No offense Jaron?

Best,

Dan (or Don ;-)
Dan Brockett is offline   Reply With Quote
Old October 5th, 2006, 01:05 PM   #32
Inner Circle
 
Join Date: Jul 2002
Location: Centreville Va
Posts: 1,828
Quote:
Originally Posted by Jaron Berman
55w biax lamps are 55 watts, as long as the ballast is driving them at the same current that is rated. kino ballasts over-drive their tubes, so technically they use 55w lamps but drive more power through them.

Lamps are rated by wattage, a measure of power. Strobes for photo are rated in joules (watt-seconds). Either way, it's a measure of power consumption. Light is measured in a number of ways, and lamps are commonly compared in foot-candles (candellas), lux, lumens etc. At home depot, they sometimes have compact fluorescents rated by "equivalent watts", or how much light a 13 watt flo will compare to a standard tungsten bulb. One thing to note is that ballasts and lamps themselves have differing efficiencies between designs and brands. Kino lamps have slightly less output than Osrams, and that's just comparing the physical lamps and not the fixtures. When it comes to lights, reflectors have a lot to do with the overall output, which is why the AH supply kit is so cool - the reflectors are extremely well designed, allowing them to, using the same lamps, project more light than Kino Diva's.

If you're comparing lights, use the actual light output as your comparison, not Watts. Watts come into play when figuring how many you can plug onto a circuit without popping the breaker.

As an interesting note, candellas are a very logical unit of light measurement. A foot-candle is the light made by one candle one foot from the measurement device. If you've ever seen Barry Lyndon, imagine literally calculating exposure by counting candles! I'm sure they used meters, but still, it would have been possible to get the exposure close by counting and measuring.

They do mention lumens at both the GE and Sylvania/Osram sites, so I guess I can compare against lumens from HMI and Incandescants and figure out the power savings from there. My question had mostly to do with caclulating how much portable power would be needed to create 4 to 5K of light. Philips is using that as marketing for their new Ceramic discharge systems (250watt consumption, 1K output).
__________________
Boycott Guinness, bring back the pint!!!
Joe Carney is offline   Reply With Quote
Old October 5th, 2006, 01:17 PM   #33
Inner Circle
 
Join Date: Jul 2002
Location: Centreville Va
Posts: 1,828
Quote:
Originally Posted by Dan Brockett
Hi Jose, I mean Joseph, I mean Joe:

I think I keep writing Jason because he seems more like a Jason than a Jaron.

No, actually because I type in a hurry and don't proof well enough. No offense Jaron?

Best,

Dan (or Don ;-)
That's HappyJose to you!!!:-). My family calls me Jose, just don't tell anyone.
__________________
Boycott Guinness, bring back the pint!!!
Joe Carney is offline   Reply With Quote
Old October 5th, 2006, 01:56 PM   #34
Major Player
 
Join Date: Mar 2006
Location: Los Angeles
Posts: 439
4-5K of what light? What style of fixture? If you're trying to create the same amount of light as a 5k tungsten fresnel at the beam center, it's a LOT different than trying to create the same output as a 5K softlight. That's why you can't really compare watts or equivalent watts, because they don't tell you what it's equivalent to. A 5k Hmi par will be brighter than a 5k fresnel par, yes, and a 220 watt fluorescent will be a lot brighter than a 220 watt tungsten softlight.

Tungsten lamps produce about 15 lumens/watt, whereas flo's produce about 80-100 lumens per watt. But you also have to factor in a lot of other things, like reflector design, size of the fixture, style of light, beam vs. field. In general, light output ratings that are advertised are center-beam readings. Tungsten lights usually produce more output at their center than fluorescent, due to the shape of the lamp itself. Flos generally make a pretty even beam all the way across (again, depending on the reflector), without hotspots. Flo's will almost always be "soft" lights. They will look different than softboxes and softlights, which is something to keep in mind if you're used to tungstend softlights. They won't provide the "punch" in the center of the beam that a tungsten will.

I know I didn't really answer your question, but it's because there's no consistent way to do it. My 4-bank flos (23"x18") are about the same output as my 2K chimera (24x32). They look VERY different, but if you're just comparing output, the flo is just slightly brighter.
Jaron Berman is offline   Reply With Quote
Old October 5th, 2006, 06:38 PM   #35
Inner Circle
 
Join Date: Jul 2002
Location: Centreville Va
Posts: 1,828
Thanks, I understand the difference and intend to mix Flo (soft) and tungsten with everything at 3200K for indoor shooting. For tungsten, I'm looking at those 500 watt shop lights and replacing the bulbs with 3200k ones at the same wattage. I know there is a lot involved, so I have a lot of work cut out for me to get everything right. I'm looking at the GE CinPlus because they have 55w 3200K tungsten, with a CRI of 90+, which puts them closer to the actual tungsten halogen in color output. Thanks for the info on lumens per watt.

I'm also intrigued by those DidoLights for close spot work.
Also seeing if including some Briteks would be a better idea instead of the shop lights.
__________________
Boycott Guinness, bring back the pint!!!
Joe Carney is offline   Reply With Quote
Old October 5th, 2006, 07:35 PM   #36
Major Player
 
Join Date: Mar 2006
Location: Los Angeles
Posts: 439
If the goal is flooding an area, shoplights will work fine. You'll need to flag them and figure a way to attach scrims if you need to do more than just flood at full power.

Dedos are amazing little lights, and they are great examples of lamps that defy standar notions of brightness per watt. They use extremely well designed and manufactured lenses and reflectors, so they definitely don't come cheap. The sharpest of their lights are the 12 volt heads. The actual size of the light "source" within is incredibly small compared to something like an arri, so if you want nice, extremely crisp shadows and cuts, nothing beats a Dedo.
Jaron Berman is offline   Reply With Quote
Old October 6th, 2006, 11:37 AM   #37
Inner Circle
 
Join Date: Jul 2002
Location: Centreville Va
Posts: 1,828
Thanks again. I purchased a couple of 250watt shop lights at Home Depot, one of them came with a variety of attachment devices (clamp, spike, stand..).
One thing I can't seem to find is a 3200K 78mm Double Ended T3 type bulb.
There were several at 2700K.
Several options at 500watts, but nothing at 250 or smaller.

Anyone know of any place to check? (First place I went to was FilmTools).
__________________
Boycott Guinness, bring back the pint!!!
Joe Carney is offline   Reply With Quote
Old October 13th, 2006, 06:01 PM   #38
Inner Circle
 
Join Date: Jul 2002
Location: Centreville Va
Posts: 1,828
Jaron, can you post pictures of you Flo kit? Just for reference?

Would scrims work the same way with Flourescents as tungsten?

Thanks in advance
__________________
Boycott Guinness, bring back the pint!!!
Joe Carney is offline   Reply With Quote
Old October 14th, 2006, 11:06 AM   #39
Major Player
 
Join Date: Mar 2006
Location: Los Angeles
Posts: 439
Well, if someone could tell me how to post pics, I would be happy to put them up.

In terms of scrims, yes, they will work fine. ND gel will also work, because the lights never get hot enough to melt through.
Jaron Berman is offline   Reply With Quote
Old October 22nd, 2006, 03:36 PM   #40
Trustee
 
Join Date: Oct 2003
Location: Rio de Janeiro, Brasil
Posts: 1,137
Some time ago I did post in this forum some explanations on the 4-pin / 2G11 units I was using, adapting artifacts I found in local light fixture shops.

One of them was a chinese plastic unit, that I bought in Argentina, using one 36watt lamp. What I did was change the ballast, to use a 110/220v type instead of 220v only, and install an AC 3-pin socket. It's so light that you can gaffer tape it anywhere, like to a monopod I have. It has a plastic diffuse cover which can slide in or out to change light quality.

The other uses two 55W lamps, encased on a metal case designed to hang from the ceiling. It's much heavier than the other and it needs a tripod. It has separate switches for the lamps and a sanded glass diffuser. In fact it's the glass that makes this unit heavy, and a plastic diffuser should be more effective.

The color of any of these lamps can be easily balanced on-camera or corrected during editing. You can usually can pick 3000k or 5000K lamps, but what you should look for is the CRI number to be high. These are examples you can find at bulbs.com:

http://www.bulbs.com/products/produc...nventory=12610

http://www.bulbs.com/products/produc...nventory=11722

The first one costs $28.50, the second $8.00. CRI is 91 on first and 82 on second. CRI is an indicator on how linear/less spiky the unit is. The higher the number the more linear the lamp is, which is better for photography.

But high frequency lamps have a great advantage over 50/60Hz fluos, which is they don't flicker, so even the worst CRI types can be used if you correct the green a little with gells or celophane. Being cool running means you can use the latter too.

This all converts these lamps into very powerful, beautiful lighting tools, which we can DIY relatively easily.


Carlos
Carlos E. Martinez is offline   Reply With Quote
Old October 22nd, 2006, 08:03 PM   #41
Inner Circle
 
Join Date: Jul 2002
Location: Centreville Va
Posts: 1,828
For the GE Cinema Plus biax (2G11) 55w, you can get the 3200K with 90+CRI from B&H for 22.95 (They're listed as ARRI, but are made by GE).
http://www.bhphotovideo.com/bnh/cont...ist&sku=384528

Here is the link for the 56K ones..
http://www.bhphotovideo.com/bnh/cont...ughType=search
__________________
Boycott Guinness, bring back the pint!!!
Joe Carney is offline   Reply With Quote
Old November 11th, 2006, 05:42 PM   #42
Major Player
 
Join Date: Dec 2003
Location: LA, California, USA
Posts: 224
I just thought I'd mention a neat versatile mounting mechanism I recently discovered, as that seems to have been the "weak link" in DIY Kino-like construction. It costs about $35, but could work very well. What you need to buy is

1 Avenger Gab Gobo - $23.99 from B&H

and

1 Avenger Baby Wall Plate - 3"- 11.95 from B&H.

Just mount the baby wall plate onto the back of a standard 2 or 4 bank fluorescent light (found for $20-$30 at Home Depot), throw in some High CRI bulbs (Another $10-$20), and use the Gab Gobo to mount to a light stand, and you're done! Total Cost for lights, not including stands, $50-$60.

You may want to pull the ballast out of the electronic light fixture and mount it externally if you don't have heavy duty light stands though.
Ari Shomair is offline   Reply With Quote
Old February 17th, 2012, 11:01 AM   #43
Regular Crew
 
Join Date: Feb 2012
Location: Orlando, FL
Posts: 27
Re: Where to get high frequency flourescent ballast? (DIY Home made Kino Flo question

Ok, well been reading up as much as possible.

Since I don't need flightworthy cases or anything and am only using personally, seems like I can just get cheap fixtures from Home Depot that already include a diffuser in case I want it, and install some reflectors if missing.

Really just looks mainly like I'l have to replace the ballasts and then get some real kino tubes.

I'm assuming it's probably easier to go the t8 route as they're very common, other manufacturers make similar bulbs, etc, so maybe less stress if i need to replace something?

Would welcome input though if there's a strong reason for going with t5 or something instead.

I checked into all the ballasts mentioned here, and they're all pretty easy to find. If I go with a workhorse ballast, there are several models, though, and want to make sure I'm grabbing the right one.

I'm no electrician, so thought I'd give a brief description.


Basically, I don't want to use dimmers. I don't want to have to deal with shifting colors, so I'd rather just have lots of on/off switches. Looking to do at least a 5 point system to light a large 8x15 foot wide greenscreen stage that comes out 12 feet. I'm figuring each one of those 5 points should probably have at least 4 bulbs... but I'll be looking at some software tomorrow to help figure out total light needed.

Correct me if I'm wrong, but I think if I've read correctly that the load shifts or whatever if fewer bulbs are running on a ballast, which changes their ballast rating or power rating or whatever... so if I want things even with no weirdness, is it best to say run only 2 bulbs per, and just have a separate on/off for each 2 lights?

If so, I just want to make sure I'm pairing up the exact right ballast for the lights. If I've read correctly, workhorse 5 would be ideal for a pair of t5's right? Is it still the right choice for a pair of t8's... and/or should I be going t5 for some reason?

From what I've read about the workhorse ballasts, they're "self adjusting"... does that mean they can't be "overdriven" like the kino ballasts? Other than total light output, is there a good reason to "overdrive" them? ... just want to make sure I get the right ballasts. They all seem pretty easy to get... and on ebay now, a number of people have a few of this one or that at a substantial savings even over the big box stores.
thx.
Greg Stout is offline   Reply
Reply

DV Info Net refers all where-to-buy and where-to-rent questions exclusively to these trusted full line dealers and rental houses...

Professional Video
(800) 833-4801
Portland, OR

B&H Photo Video
(866) 521-7381
New York, NY

Z.G.C.
(973) 335-4460
Mountain Lakes, NJ

Abel Cine Tech
(888) 700-4416
N.Y. NY & L.A. CA

Precision Camera
(800) 677-1023
Austin, TX

DV Info Net also encourages you to support local businesses and buy from an authorized dealer in your neighborhood.
  You are here: DV Info Net > The Tools of DV and HD Production > Photon Management

Thread Tools Search this Thread
Search this Thread:

Advanced Search

 



Google
 

All times are GMT -6. The time now is 10:51 PM.


DV Info Net -- Real Names, Real People, Real Info!
1998-2017 The Digital Video Information Network