90 vs 60 vs 45 Degree Louvers for Kino Flo's
 

Just got the Kino Flo Barfly 200 2-unit kit which comes with 90 and 60 degree louvers. I see that the 60 limits the spread of light, and a 45 degree louver would limit it even more. However, my question is whether the smaller angle actually 'focuses' the light, thus, increasing the intensity OR does the smaller angle just keep the intensity the same while reducing the spread.

I have an event Tuesday night, and need to determine the best lighting setup beforehand. I will only need to light the upper half of a podium for a single speaker. I am wondering if I can keep the lights an extra foot or two away by using 45 or 60 degree louvers.
...OR...
Removing the louver seems to increase the light intensity a good amount. I have one Snoot for the Barfly 200 - so, what about using a snoot on one of them with no louver.

I am somewhat new to flouro lighting so go easy on me.

Thanks.

My advice would be to test before your shoot.
Here are some helpful specs.

Kino Flo BarFly Photometrics

Thanks David. Thanks to your link, I found PDFs showing light data for each louver. If I am reading it correctly, the louvers don't 'focus' the light - they only limit the spread of light, which does reduce the intensity for all angles except straight on (90 degrees).

The also have a PDF showing "Open Face" - there is 25% more light at 90 degrees and naturally, a lot less falloff.

Hi Steve:

Since you are new to fluorescent lighting, I'll offer a few observations...

1. The Barflys are pretty cool little lights, I really like them. I had a chance to evaluate the 400s for an article I wrote for HD Video Pro Magazine last year on green lighting. Any lights, even tungsten sources with a softbox, lose a significant amount of pure output when using egg crates/louvers.

2. You will find that in comparison to tungsten and HMI instruments. the falloff on fluoros is much quicker so you will have to typically physically locate your lights closer to talent that you would have to with conventional sources.

3. Louvers are useful for containing the light but if you have C-stands, flags and cutters on set, they can do it well also without the output loss of using louvers. Kind of negates the whole small and light thing though, one of the big advantages of shooting with Barflys. Lately I have been using small and light stands and arms, combined with Cinefoil flags I have made on set. These setups weigh 1/4 of the weight of a steel C-stand and a traditional 24x36 flag and with small sources like a Barfly, you don't need full sized flags.

Best of luck on your shoot.

Dan