View Full Version : light beam


Buba Kastorski
October 5th, 2009, 09:51 PM
what light can produce narrow, adjustable beam of light, I'm guessing smthng from DJ's department, but I could be wrong,
thanks.

Bob Grant
October 6th, 2009, 01:15 AM
what light can produce narrow, adjustable beam of light, I'm guessing smthng from DJ's department, but I could be wrong,
thanks.

Something like this Source 4 Ellipsoidal Light 750W 36 Degree 436 - Source 4 Ellipsoidal Light 750W 36 Degree 436 (http://www.filmandvideolighting.com/so4elli7536d.html) ?

If that's no good then a follow spot.

Giroud Francois
October 6th, 2009, 11:12 AM
depends power needed but for a light projector (for a presenter), i use a LED flashligt
search on ebay for "109 led"
Ultra Bright 109 LED Camping Hiking Flashlight Torch 17 - eBay (item 250378084379 end time Oct-20-09 15:07:00 PDT) (http://cgi.ebay.com/Ultra-Bright-109-LED-Camping-Hiking-Flashlight-Torch-17_W0QQitemZ250378084379QQcmdZViewItemQQptZLH_DefaultDomain_0?hash=item3a4bb2601b&_trksid=p3286.c0.m14)

it is pretty powefull and run on a set of 4 AAA cells for hours.
i just made a tube on a mic stand so i can slide the light in. takes 30 sec to set up.
you can add a lense from a magnifier on a carton/pvc tube so you can even focus more the beam. In that case you will need to add some white plastic diffuser or you will get the pictures of the leds against the wall. cost les than 30$

Buba Kastorski
October 6th, 2009, 08:53 PM
thanks Bob :)

Boyd Ostroff
October 7th, 2009, 08:51 AM
Something like this Source 4 Ellipsoidal Light 750W 36 Degree 436 - Source 4 Ellipsoidal Light 750W 36 Degree 436 (http://www.filmandvideolighting.com/so4elli7536d.html) ?

That's a unit with a 36 degree lens, which is relatively wide angle. It depends on what you are trying to do, and how far away the light is, but a narrower beam will be brighter (putting the same amount of light into a smaller space). A 19 degree unit may be a better choice. See this table from the manufacturer to choose the correct lens system: http://www.etcconnect.com/docs/docs_downloads/miscdocs/Source%204%20Beam%20Spread%20Table%2000-11-13.PDF

The standard source four produces a round beam which can be shaped with 4 moveable shutters. So if you want to make the beam smaller you would close the shutters which results in a square shape. If you want a round beam you would need to use a different kind of instrument or drop an iris into the source four (which costs extra).

Of course there are other instruments which can also give you a narrow beam of light, so it depends on what you are trying to accomplish. Do you want a visible light beam? You will probably need to use a haze machine for that effect. The light beam will be the most visible if it comes from above and behind, due to the way it reflects off dust particles (or theatrical haze) in the air.