Concentrating a fluro?

[dan_lee16]

<p>Hey guys,</p>

<p>So I got some new continuous lights to play with (already got some flash units for still photography), theyre claimed as 6500K (I measured 6400K on my 30D shooting a white envelope), which is pretty good, as I'd like indoors to look cooler against an outdoors background (or the day exterior to look warmer).</p>

<p>Anyway, Im impressed with the amount of light they put out (a pair of 105watt fluro bulbs per light unit, I got 2 units) one unit is adding about 4.3 stops over the indoor available light (window light bounced around).</p>

<p>But theyre not in a reflector cone/bowl, but open, I noticed when I put a shoot-through umbrella behind them as a soft reflector I gain a small increase (mabe 1/4 a stop).</p>

<p>Obviously there is a lot of light wastage for many scenarios, and I'd like to re-direct to the smaller area Im actually shooting, instead of having 360 degree light :)</p>

<p>Is my best bet to put a reflector bowl around them (like I've seen on other fluro's of this type)?</p>

<p>Is it possble to harden the light using this method? As that would be an extra bonus/convenience :)</p>

[joseph_wisniewski]

<p>It's difficult to harden or focus a 105W fluorescent.</p>

<p>How long is the tube, 6 inches? The actual focus of a bowl or parabola is smaller than that, so only a small portion of the tube is at the focus and getting columated (a "fancier" word for what you're calling "hard"). Paradoxically, larger reflectors (big focused umbrellas or big bowls) will do a much better job than smaller ones. You often see low cost lighting kits with 4 or 6 inch tubes in 12 or 15 inch wide, 8 inch deep reflectors, and most of the tube is so far from the focus of those small reflectors that they're pretty uncoltrolled, not columated, and there's hot spots and weird fethering of the light.</p>

<p>Find a big old reflector, the kind often used with 1000W "mogul" photofloods, note where the center of the bulb sits in relation to the reflector, and cut out the back and rig a mount to put the center of your tube at that same location. Or try the Westcott PLM "parabolic" umbrellas. Without socks, they're "hard", and bright (very efficient at using light). With more effective power, you can back them away from teh subject a bit, further increaseing the appearance of "hardness".</p>

[joseph_wisniewski]

<p>Forgot to mention, look for reflectors that have barndoors or grids (or both). The barn doors control stray light, which keeps if from reflecting back onto your subject from odd angles and destroying your "hardness", and the grids can make light pretty strongly parallel and much more "directional" looking.</p>