compact flourescant "hot lights"

I was browsing ebay for deals on lighting setups and I came across these compact flourescant light bulbs, touted to closely replicate natural sunlight with a power rating of 250+ watts (depending on the bulb) while only using 50 watts of electrical power.

Has anyone ever used these? Are they a good alternative to using power sucking hot lights?

Depending on the film you use, and the exact lamp, you may get a funny color rendition. Look for a Color Rendering Index (CRI) of 90 to 100 to get a bluish - daylight output.

I like them for some work: you may need an 'extension' of the base to fit the lamp in a dish reflector.

TEST it with the film you prefer: the output spikes across the spectrum, and you may or may not get what you hope for.

df cardwell said:

Depending on the film you use, and the exact lamp, you may get a funny color rendition. Look for a Color Rendering Index (CRI) of 90 to 100 to get a bluish - daylight output.

I like them for some work: you may need an 'extension' of the base to fit the lamp in a dish reflector.

TEST it with the film you prefer: the output spikes across the spectrum, and you may or may not get what you hope for.

Click to expand...

Thanks. I guess it's worth giving them a try, what's the worst that can happen right? a couple bad rolls of film.

df cardwell said:

Depending on the film you use, and the exact lamp, you may get a funny color rendition. Look for a Color Rendering Index (CRI) of 90 to 100 to get a bluish - daylight output.

I like them for some work: you may need an 'extension' of the base to fit the lamp in a dish reflector.

TEST it with the film you prefer: the output spikes across the spectrum, and you may or may not get what you hope for.

Click to expand...

Have you tried them with B & W? If so, with which film, and what was the result?

Thanks,

Matt

AeisLugh said:

I was browsing ebay for deals on lighting setups and I came across these compact flourescant light bulbs, touted to closely replicate natural sunlight with a power rating of 250+ watts (depending on the bulb) while only using 50 watts of electrical power.

Has anyone ever used these? Are they a good alternative to using power sucking hot lights?

Click to expand...

The power level sounds like a lot but I bet you'll find the output pathetic. Unless you're using real fast film and very fast lenses.

I think it would be possible to build a light bank using CF but it'll take a lot more then 50watts of CF power. I wonder if an 8' light fixture with tubes would make more sense then a bunch of CFs.

Mine tend to run blue, and a tiny bit green. I'm fine with that.

If I'm using a 50 w fluoro, I figure it is like a 200 w.

The 2 advantages are a greater useful output (near daylight is faster ! )
and LESS HEAT. So, put 4 on a plywood board and you have a 1000 watts that won't burn a subject when you bring it close.

The long tubes are the most efficient, but the compacts let you make a 30"x30" box which is very handy.

1/2" foam core is also handy.

THEY ARE SUPER FRAGILE.

d

AeisLugh said:

Has anyone ever used these? Are they a good alternative to using power sucking hot lights?

Click to expand...

I just bought 4 5500K bulbs from bulbman.

What Kelvin rating did you get? I think if it is over 5K or 51K, that is daylight balanced. Mostly B&W work.

My local Home Depot sells 4 ft. Philips C50 Colortones, 5000K and CRI of 92. I use them overhead in my darkroom, study, and other rooms. They are only $5 or so each. I've only shot Fuji Pro 160S under them, with a tiny green shift in the shadows from a local 1 hour lab. Otherwise a MacBeth Color Checker looks good. Can't say at this point whether the green shadows are crossover or not. I've used GE Chroma 50 4 fts as well, but haven't shot critical color under them. I use them for judging prints, both color and B&W.

From what I've been able to find, the high CRI lamps use differing numbers of phosphors, up to seven that I've seen claimed, and it makes sense to me that more phosphors mean more even spectral distribution with fewer dips in output across the spectrum.

I've used the 5000K Edison base spirals in spun aluminum reflectors as well, mostly through diffusion scrims, but only with B&W. So I can't say much about their color qualities on film.

Lee