Advice on fluorscent fixtures/bulbs for Lowel Rifa softbox

G

gentaylor

Member
Hi,

I've had a Lowel Rifa ex55 kit for years and love it. I've always used tungsten bulbs and mainly shoot interviews for documentaries. Recently I've learned that I can swap in a fluorescent fixture for a cool, daylight balanced key light for natural light situations w/o the need for CTB gels. But I have zero sense of how bright this will be or the quality of the light.

The fixtures come in single and triple bulb versions, as seen here:
http://www.bhphotovideo.com/c/produ...1_Rifa_eXchange_Fluorescent_Incandescent.html
http://www.bhphotovideo.com/c/product/497651-REG/Lowel_FLO_X3_Rifa_eXchange_Fluorescent_3.html

Does anyone have experience using the Rifa with fluorescent bulbs? If so, can you talk about the difference in light quantity and quality?

For example, Is the one bulb fixture (30W fluorescent) similar in light output to the single tungsten (500W) I normally use? Or do I need the 3 bulb fixture (3x30W) to match the light output of a single 500W tungsten bulb?

Also, does a fluorescent key light mix well with fill and rim lights that are tungsten with CTB gels? I normally use a tota light for the background and a pro light as a rim light.

Thanks so much for the input!
 
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You can compare the photo metrics for various lamp and Lamp Head combinations in the charts here - http://lowel.tiffen.com/rifa/rifa55_b.html#info (You may have to scroll down a bit).
Find the intensity for the tungsten lamp you are using now in the standard TH-X1000 Lamp Head in your eX 55 and compare the intensities at the same distance for other lamp and Lamp Head combinations to get an idea on what to expect.
 
From the look of it, you need at least the 3x65w or 3x80w fluorescent arrangement to match the output of your usual 500w. That sounds about right to me since most fluorescents are about 2-4x as efficient as halogen so I would expect you need at least 125-250w of CFLs. Spiral CFLs and in particular an arrangement like the rifa flo x3 tend to lose a fair amount of efficiency in their geometry since much of their output is blocked by other parts of the bulb or by other bulbs.

On the other hand, a 3x30w daylight fluorescent setup would probably just beat the 500w tungsten with full CTB on it... but then unless you opt for the bigger CFLs it probably makes more sense to stick to the 500w tungsten with CTB when you want daylight.

Frankly using CFLs in softboxes never really made much sense to me since getting enough output usually requires carrying around too many too large fragile bulbs and taking the bulbs out all the time to keep them safe. That said, CFLs in softboxes do tend to have a somewhat softer, more even output than tungsten given the same photometrics, to get quite the same quality of light you might need heavier diffusion or a diffusion baffle with the tungsten, but that goes abit more for softboxes mounted on fresnel or par lights than a rifa so I'd say stick to your tungsten and maybe look into newer LED options.
 
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Thanks for these replies. I have decided to wait and will likely invest in LED lights. With new products coming out this summer, I'm hoping to put together a kit. Just can't quite decide between the various options yet (Cineo, Kinotehnik, Aputure, etc.). Thanks again for this feedback!
 
I got the 3- and 5-bulb EX modules used to try out the CFL-in-a-softbox concept... since I was going inexpensive, I sampled a few "Home Depot" brands to see what worked/didn't.

For CFL, I landed on ~200W-equivelent daylight CFLs from, of all places, Tractor Supply. Many of the other daylight CFLs lay in the ~6500K range, which doesn't match well with exterior daylight. These lights were at least closer to the ~5600K range. In the early spring, they can even double as grow lights for tomato seedlings, and I love multi-usiosity. The quality of light isn't as good as a stock gelled tungsten, but better than some cheaper LED panels I've tried.

As an alternate, I REALLY like CREE-brand bulbs (LED, available both tungsten and daylight). They're available up to 100W-equivalent, and put off a really nice quality of light. I have a box of both to relamp practicals in a scene as needed. In the EX-3 setup within a RIFA55, they really benefit from less diffusion than the stock setup, so I'll shoot them through a sheet of 1/4 or such instead.

All that said, nyvz is spot on about the dubious utility of it... needing to carry the bulbs and EX modules significantly decreases the portability of the RIFA setups, which is one of their main attributes. In the case of the CREE bulbs, at least I'd likely be carrying them anyway, and they're far more durable than any CFL.

My most compact quick & dirty daylight key is simply a Lowel V-light gelled with 1/2CTB shot through an umbrella. Looks pretty darned good for what it is, and easily fits in a backpack or flight case.
 
This has become kind of a stock reply for me, but… consider a chinese kino knock-off (quad biax flo fixture). they're down as low as $200 nowadays and it's about 1k worth of nice soft daylight. True, they don't ship with Kino lamps (often Osrams) and a bit of gel is sometimes needed. But pretty no-brainer for the money. LEDs haven't really dialed in the color until very recently and you'd likely spend a grand for something with really, really good color (yeah, I know, there's a lot of folks on this site that love their $200 whatever panels, but I've seen some really poor results). Quads and duals have a lot going for 'em.
 
Michael Carter said:
This has become kind of a stock reply for me, but… consider a chinese kino knock-off (quad biax flo fixture). they're down as low as $200 nowadays and it's about 1k worth of nice soft daylight. True, they don't ship with Kino lamps (often Osrams) and a bit of gel is sometimes needed. But pretty no-brainer for the money. LEDs haven't really dialed in the color until very recently and you'd likely spend a grand for something with really, really good color (yeah, I know, there's a lot of folks on this site that love their $200 whatever panels, but I've seen some really poor results). Quads and duals have a lot going for 'em.
Click to expand...

+1 on this.

The light quality + Ease of setup + Price = Darned good option.
 
Michael Carter said:
This has become kind of a stock reply for me, but… consider a chinese kino knock-off (quad biax flo fixture). they're down as low as $200 nowadays and it's about 1k worth of nice soft daylight. True, they don't ship with Kino lamps (often Osrams) and a bit of gel is sometimes needed. But pretty no-brainer for the money. LEDs haven't really dialed in the color until very recently and you'd likely spend a grand for something with really, really good color (yeah, I know, there's a lot of folks on this site that love their $200 whatever panels, but I've seen some really poor results). Quads and duals have a lot going for 'em.
Click to expand...

Can you link to some amazon lights you are referring to? i might be interested in this but dont see them for that bright for $200
 
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