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-   -   Inexpensive fluorescent setup (https://www.dvinfo.net/forum/photon-management/53366-inexpensive-fluorescent-setup.html)

Dennis Wood October 26th, 2005 08:40 AM

Inexpensive fluorescent setup
 
I've posted some PICS of a few quick shots comparing 4 foot Phillips TL950 tubes (5000K 98CRI) to halogen worklights and CF's.

I'm on the low end of the learning curve on video lighting in general, but I've done enough reading here and at dvxuser to get me started. I'm still working on mounting these lights as they are two light fixtures (T8's with electronic ballasts) purchased for a whopping $16US each.

I'm interested in any comments from the lighting gurus here.

Wayne Orr October 26th, 2005 09:09 PM

Let's see if I can answer a few of your questions, Dennis, and give you a couple of other comments.

1. Certainly you can gang the units together to create a four lamp unit, but it will probably be pretty ungainly using "shop" gear. One of the great things about KinoFlo lights is their light weight housing, and putting the ballast on the floor with a long cord to the light. This makes placing their lights quite simple. So if you are going to create a kit that consists of all fluorescent shop fixtures, yipes. Lots to carry on location.

2. In theory, it hardly matters whether you mount them horizontally or vertically. In practice, it may have more to do with the space available. Also, watch for the pattern of the lights in eyes.

3. As far as using them as a kit, refer to my comments above. With a soft source such as you get from a fluorescent fixture, you hardly need a fill for portrait work. Usually just a bounce card will suffice for fill.

4. You can use a fluorescent for a back light, if you like that sort of thing, but again, it is such a big instrument, it is not efficient for toting around. One of your halogen shoplights would be a better choice, but it is probably closer to 3200K. Try it.

Here are a couple of other things to notice in your pictures. Look at the shadow on the wall from the two different lights. You will note that the fluorescent light casts a much softer shadow than the halogen. That's a big advantage in lighting people. OTOH, notice how much the light drops off in the fluorescent picture. The white bench looks OK, but behind it and below it there is definitely less light. This is a problem with fluorescents when using them to light a set. You need a lot of them.

IMHO, making a lighting kit out of just shop fluorescents is too limiting. You need some harder instruments for other applications.

Wayne Orr, SOC

Dennis Wood October 26th, 2005 11:12 PM

Thanks for your reply Wayne. I am considering actually dismantling the units and hadn't considered relocating the ballasts, but that's a great idea. I'm pretty convinced also that a parabolic reflective surface behind them would increase light output a lot. Ultimately, as I'm an amateur at best, I'd like to have these lights multifunctional..meaning useful as shop lights too. This will sound kind of funny, but SAD (seasonal affective disorder) is an issue for many here as winter days shorten. Very bright full spectrum light therapy is often prescribed....hence another side job for these lights. I had searched for the Lights of America 65 watt fluorescent work lights at 6500K, 85 CRI but these are not sold in Canada AFAIK.

For my little test the lights were all leaning against a wall about 8 feet away, pointing up slightly, so hardly the best setup for them. The halogens on the other hand were on the stands they came with....so better light angles.

I did notice the much more diffuse shadow from the flos, and I'm thinking this is kind of a soft box effect, without the box. The only effective way to tote around 4 foot fixtures is going to be to have them clamp together to protect the bulbs....so it sounds like a fluoro back light is doable. Fortunately I own a van :-)

Mike Cavanaugh October 27th, 2005 11:04 AM

You might consider Compact Flo kits made up for aquarium set-ups. They are available with dome type reflectors and the bulbs come in different color temps and CRIs as wellas a range of wattages.

For some ideas, look at: http://ahsupply.com/bulbs.htm

Dennis Wood October 27th, 2005 11:38 AM

Thanks Mike. The kicker here is that I already have the 25 bulbs and fixtures. I'm very interested in trying a few parabolic reflectors similar to this.

Of course instead of a copper water pipe at the focal point (P) I'd have 1 or 2 four foot bulbs. I've yet to find such a reflector on the web. I did find Winplot which allows you to print templates for parabolic curves (or any others). These patterns would be used to form the parabolic reflector end plates.

Matt Irwin October 27th, 2005 02:30 PM

For the parabolic reflecter, you could use plastic rain gutter. I know it sounds totally lame, but I've made a 2 lamp T12 fixture with endcaps and a nice black paint job and nobody would ever know it's a rain gutter. I have mine with a white reflector but if you want more punch, PepBoys sells mylar mirror tape designed to go on a car body. If you wanted to soften the light after that, you could cut to size a piece of tranluscent Plasticore (called Coroplast in Canada) and mount diffusion gel behind it, and then mount the whole thing to the light with velcro. You can also gang the rain gutters together to make a flat 4, 6, or 8 bank light.

Some good craftsmanship can go a long way with home built lights, and can fool people into think they're anything but...

Dennis Wood October 27th, 2005 07:53 PM

Matt, I hadn't thought about the plastic option. I was wondering actually about RF and the electronic ballasts. Do you have RF issues? Wayne had mentioned the Flo system with the ballast on the floor and I really like that idea...but I wonder about shielding.

I was thinking the same thing about using mylar or possibly polished aluminum for reflectors. I played a bit with the winplot program which will allow a perfect parabola template. So basically a setup with external ballast and a near perfect parabola mirrored reflector sounds like a reasonable end goal. I'm working on finishing a tracking dolly project, but this one's up next.

Matt Irwin October 28th, 2005 10:45 AM

I haven't had any problems with the electronic ballasts and RF. Just a heads up on electronics though: they are really finicky and if you don't wire them right, it can sometimes damage the ballast. Magnetics are more forgiving with wiring, but don't perform as well.
I've been running the brick ballasts out of fanny packs with zip cord/add-a-tap lead outs, but they look really un-pro and are annoying to work with, so I've started building ballast units out of ammo cans (like from an army surplus) with recessed plugs and switches. Looks much more legit now (matte plack paint works wonders).

Dennis Wood October 28th, 2005 10:56 AM

Matt, any hope of a pic or two of your setup? The ammo box idea is perfect...probably great for shielding too. You've come up with a few ideas I wouldn't even have considered.

Matt Irwin October 30th, 2005 03:22 PM

Yeah, I can post a pic. I won't be at the workspace I'm using until next friday, but I'll be sure to take some pictures.

Gints Klimanis October 31st, 2005 05:47 PM

full spectrum bulb deals
 
>65 watt fluorescent work lights at 6500K, 85 CRI but these are not sold in Canada AFAIK.

I found Philips Colortone T12 (C50) 5000K, 92 CRI selling for $100/case of 30 at Home Depot. You just break out the case and get a great deal. The very same bulb is individually packaged across the aisle for $5.97. Any of these bulbs are horrible on my aquarium, but they are fantastic in my video studio,
which is my martial arts training room in my garage. I also fitted another
dojo with 48" ($3) and 96" ($8?) Colortones (also from Home Depot), and they mixed well with daylight and flash.

Dennis Wood October 31st, 2005 09:06 PM

Glints, I went the case route as well with 25 Philips TL950's (5000K 98 CRI) from a local electrical supplier. I paid $118 US ($140 CAN) so about $4.72 US a bulb.

These are the T8 bulbs designed to work with electronic ballasts, design lumens are 2000 per bulb.

Dennis Wood October 31st, 2005 09:16 PM

duplicate message...

Gints Klimanis October 31st, 2005 09:28 PM

Hey Dennis,

I have the same Philips T8's you have as well, though I think you landed a slightly better deal on the case. They're great, but somehow, the T12 bulbs from Philips with similar specs (5000K and 98 CRI) seem to look better.
I have several banks of T8's (Home depot fixture from Lithonia Lighting), but when I added the Philips T12 bulbs to just a pair of existing fixtures, the colors took off ! On paper, the T8's seem better, though.


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