DV Info Net

DV Info Net (https://www.dvinfo.net/forum/)
-   Photon Management (https://www.dvinfo.net/forum/photon-management/)
-   -   Eggcrate Beam Angle (https://www.dvinfo.net/forum/photon-management/94351-eggcrate-beam-angle.html)

Deke Ryland May 18th, 2007 08:46 AM

Eggcrate Beam Angle
 
Hey guys... I shoot mostly interview style setups in a small studio that is about 12x15' in size and use a 250w Lowel Rifa-Lite Softbox as my Key Light. However, because the room is so small, I am getting a lot of spill from the softbox and am interested in getting an eggcrate to help get rid of some of that spill.

The problem is, I am unsure if I should get the 40 degree beam angle eggcrate or if I should get the 30 degree beam angle eggcrate. Because my lights are 'general purpose' lights, I don't want to get something that is too constricting, but like I said, I mostly shoot in small rooms and try to acheive a more 'dramatic' look to my interview style shoots.

Any suggestions or guidance would greatly be appreciated. Thanks for any help.

Dan Brockett May 19th, 2007 07:59 PM

Reply
 
Hi Deke:

A lot of this has to do with distance from subject to BG. If you have enough separation between the two, a 40 degree is fine. If you are tight on room, a narrower egg crate may be better. Keep in mind that the narrower the angle, the higher the light loss overall. With a mere 250 watt Rifa as a key, you may run out of horsepower with the light in some situations.

I own five Chimeras and have 40 degree egg crates for all of them. I am happy with the results.

Dan

Deke Ryland May 20th, 2007 12:47 PM

Do you see a very noticeable difference between using no eggcrate and using the 40 degree eggcrates?

It just seems like everyone I talk to gets the 40-degree eggcrates... I don't want to stray away from the crowd, but if a 30-deg is what is needed for small studios.. then I guess that would be the perfect fit, you think?

Dan Brockett May 20th, 2007 07:02 PM

Reply
 
Yes, there is a large difference.

No eggcrate = giant uncontrollable ball of soft light
40 degree eggcrate = semi-controllable ball of soft light with reduced output over not using an eggcrate.

I am thinking your 30 degree on a wimpy light like a 250 will reduce output too much, unless you have a VERY sensitive camcorder like the DVX-100A/B.

You will need to run tests to determine how much spill you get on your BG. That is the main function of an eggcrate in most situations, it doesn't matter if your light's output is bleeding all over the floor usually or out of frame usually. What you are trying to avoid is lighting up your BG when in smaller locations where you have difficulty separating the subject from the BG. You can reduce this effect by moving your key closer to 90 degrees from camera than you normally would but then you will need to increase the amount of side fill and fill coming from underneath (assuming you are in a physical setup where you can use side fill and underneath fill?)

The closer your key is to on-axis with the camera, the more spill on the BG, assuming you are seeing the BG on camera. By moving in further off-axis, you are commensurately reducing the amount of spillage onto the BG, BUT you will have the film-noir look with heavy shadow on the non-key side. To solve this, add fill on the opposite side and underneath.

I think that they even make 20 degree eggcrates but they are a lot more expensive and once again, cut down the overall output of the light significantly, which in your case is probably not a good thing. There really is no substitute for having a large enough room to separate the talent from the BG.

Best,

Dan

Bob Grant May 21st, 2007 07:39 AM

Why not use a cutter to cut the spill?

Guy Cochran May 31st, 2007 11:40 AM

Lighttools makes the Egg Crate for the Lowel Rifa.
Check this out http://lighttools.com/technical2.html

I agree with Dan, the 250W "baby Rifa" with a 40 degree Egg Crate cuts the light significantly. You'd want to position the light fairly close to your subject if you went that route.

A 500W Rifa with a 40 degree works pretty well, even at a distance of 5-7 feet.

BTW,

Have you seen the new Rifa eX??? http://lowel.com/news/news27.html


All times are GMT -6. The time now is 03:19 AM.

DV Info Net -- Real Names, Real People, Real Info!
1998-2020 The Digital Video Information Network