Alien Bees and Neutral Density Filters

[howard_grill]

I have been trying to find a way that is simple to use neutral

density gels with Alien Bee strobes in a Photoflex softbox. I just

tried using velcro to place a sheet either over or under the entire

outer diffusion panel but it is definitely a pain in the butt as the

film is very thin.

 

It seems the easiest way would just be to clip a piece onto the

inner diffusion panel. But, I am wondering...will this cause a

somewhat 'hot area' around the perimeter of ligth coming from the

softbox resulting in uneven exposure, or does it all basically mix

and come out with even lighting despite the fact that the ND film

does not cocer the entire area of the inner box?

 

Howard

[steve_levine]

I'm not familiar with Alien Bees, but don't they have a way to lower the power without monkeying around with ND gels?

[howard_grill]

Yes, but the power range I need for all the situations is quite wide and when you turn the power way down there can be some issues with change in color temperature, so I thought the ND would be a nice way to go...if there were a simple way to do it.

 

Howard

[streetlevel]

order a piece of black scrim material from a supplier (I use setshop.com). They usually

come in a few weights, you can clip this on the outside of the softbox (use a large enough

piece and you can double it over for more effect, if you need to).

[garry edwards]

Reducing light output can be an issue with any make of lights, including those that have consistent colour output.

 

Lee filters supply 4' x 25' rolls, cut a piece to size and clip it to the front with clothes pegs (clothes pins in the US)

[howard_grill]

Gary...thanks for the idea. Will, I am new at this. What is scrim material?

 

Howard

[jonathan_brewer1]

Scrims consist of a black netting stretched over a frame which when placed in front of a light source, will knock down the ilumination of that light, a 'single' is a scrim which will knock down the ilumination of your lightsource by a half stop, a 'double' knocks down the illumination one stop. So not only do scrims come in different shapes but in different strengths, that is, singles and doubles.

 

Scrims traditionally came in three basic configurations, 'dots', fingers, and open ended scrims, an open ended scrim has a wire frame on three sides and one side is free so that you can place this light mod in front of a light source without projecting a 'seam' onto whatever you're lighting. 'Dot's are simply circular shaped scrims used in front of a light source to knock the illumation covering a circular area, a 'finger' is a slender rectangle shaped scrim which knocks down a slender area that appears too hot.

 

These have been refined in Motion Picture prod, thus, if the Director of Photography tells the head electrician that an area looks too 'hot' to him/her, the electrician will check the exposure on that area and ask for an 'open ended double'/a scrim w/a three sided frame that will knock down the light one stop.

 

Another advantage of an open ended scrim is that you can turn it an angle relative to light to control the transition from the ilumination of one area to another, this is done for instance for different things that are different distances from the same light.

 

Scrims, flags, cutters, can all be used with just about any light, and I would recommend you research their use by going onto a site like the Mole-Richardson site, the B&H sourcebook probably has plenty on this subject matter also, and if it's too much for you now, it'll be knowledge you can file away for later use.

[howard_grill]

Thanks for the very useful info...will do more research, as you suggest.

 

Howard

[jonathan_brewer1]

Howard................In addition to buyin a roll of this material, to knock down the illumination from the whole light, there are obvious advantages to using these differently shaped scrims on single subject matter such as portraiture and/or light placement, ON PARTS of your softbox/lights in relation to a single sitter.

 

You place your softbox off to the side and up(sometimes known as Rembradt lighting), in relation to your sitter, the illumination on the subject matter closest to the light will tend to be hotter than the off side, an open ended scrim placed between the area of the light that is hitting the closest side of your subject matter will enable you to smooth out the illumination/even out the illumination so that you have the same exposure on both sides.

 

Scrims are not only modifiers enabling you to transition/change the ilummination between different sujbects in different areas or at different distances lit by one light, but give you the ability to play around w/parts of the illumination from one light, thus affecting small parts of an object, big areas or small, they give wonderful control.