polarizing gel material

[jeff__2]

How do I photograph subjects (e.g. old family portraits) under glass without

refections?

 

I have two speedotron Force 5 flash units with 11.5 cone reflectors. Digital

SLR with circular polarizing filter on lens.

 

What specific polarizing gel material should I purchase to fit on my Speedotron

flash units so I can cross-polarize my subject? I am not finding any at B&H.

 

How does the linear or circular polarizing issue work in this situation?

 

Thanks.

[sarah_fox]

Polarize in one direction with polarizers over the flash(es). Put a polarizer on the lens, turned 90 deg from the direction the flash is polarized. Light reflecting directly off of a surface would then be blocked by the polarizer on the lens. Some light would be absorbed by the target, re-emitted in a random orientation, and then passed through the camera's polarizer (and some would also get blocked). You may use either a circular or linear polarizer on the camera; however, the polarizer on the flash should be linear. You can buy linear polarization film very cheaply. I think I got some from a company called A-Light. This technique works very well for copy work.

[brooks short]

You can also use a long lens for greater camera to subject distance and shoot from slightly off to one side. Position a large black card to reflect in the glass and use Photoshop to correct any perspective distortion that is caused by not shooting parallel to the glass.

 

The longer the lens and greater the camera to subject distance, the less perspective distortion and correction you'll have to deal with.

[Charles_Webster]

You can usually buy polarizing gel at theatrical lighting and motion picture supplies. Search for motion picture expendables.

 

<Chas>

[mark u]

Rosco stockists should carry some - including B&H, Adorama and Calumet:

 

http://www.bhphotovideo.com/bnh/controller/home?O=search&A=search&Q=&sb=bs%2Cupper%28ds%29&sq=asc&ac=&bsi=&bhs=t&ci=1329&shs=&at=Type_Polarizer&basicSubmit=Submit+Query

[dan_meyers1]

In this instance, polarizing is not the way to go. Reflections in glass are very simple to deal

with by cutting a hole in a large piece of black velvetine or velvet for the lens to poke thru. If

the glass is small enough you may get by with a black piece of foamcore or artboard. The

main point is to have a surface facing the glass that has no reflective characteristics and to

cover the camera, tripod legs and yourself with something black. Also helps to turn off any

ambient light to keep the environment from being illuminated.

[g._armour_van_horn]

Dan's right, keep the lights to the side, turn off the overhead lights, and go for it. You might want some gobos or barn doors to avoid spill onto the camera, but you shouldn't have to worry about it that much if the light on the subject is strong.

 

Van