Edited by Steven Carubia, 27 January 2011 - 12:44 AM.
self-ballasted CFL bulbs
Posted 27 January 2011 - 12:40 AM
Posted 27 January 2011 - 12:45 AM
Posted 27 January 2011 - 09:38 AM
I would just look at them at 5600k in camera if you don't have a color meter.
Posted 27 January 2011 - 11:42 AM
To test for green spikes ect, a digital video or stills camera can shot that kind of information, and I have noticed that sometimes It'll vary bulb to bulb.
One of the ways I prefer to us CFLs are in chinaballs, as I can use brighter lights with less heat in smaller china-balls and, if need be, i can throw -G on them pretty easily.
Posted 27 January 2011 - 03:52 PM
Green, mostly yes. It's inevitable in flourescents because it's in the spectrum of the mercury vapor that drives the phosphors. They all overdrive the phosphors, saturating them and a little more, to get a constant output. That'll vary with voltage and temperature, so the amount of extra green in that narrow spike, the height of the spike, is random.
Posted 01 February 2011 - 12:05 PM
I like the CFLs because I can put daylight in the lantern and get a usable amount of of light with low temperature and no worries about fire.
I used to use three Y-adapters screwed together so I could put up to four globes in the fixture, controlling the output by the number of globes screwed in but have since found some adapters that give me four sockets from one Edison base, so a little tidier and tighter than all those Y adapters.
Home Depot used to list CRI on their packaging but no longer. I've also often found there is more info on the ballasts of the globes than there is on the box. Manufacturer or distributor websites are often useful too.
I don't think a color temperature meter is terribly useful with these things because of their spiky discontinuous spectrum but still and movie camera tests tell the tale.
Posted 02 February 2011 - 02:30 AM
Posted 02 February 2011 - 02:38 AM
Posted 02 February 2011 - 04:59 AM
This product also claims to have a color temperature of 2700K (accurate?) if that has any bearing on green spikes.
No, the green spike is generated by the green spectral line in the mercury vapor arc that is the electrical basis of operation of a fluorescent. It "leaks" through the phosphors on the inside of the glass envelope.
Posted 02 February 2011 - 02:38 PM
I've just learned that the CFL I posted a picture of has a CRI rating of 82. Does that help narrow your responses?
A CRI of 82 is not particularly good. Generally, you would want >90. That said, all cameras differ in their response to the green spike, so you may get away with a lower CRI.
Posted 02 February 2011 - 02:45 PM