Öppet Forum > cross polarized light

I'm new here, so I wanted to say hi :)
My name is Mirek and I am from Poland, so please answer in this thread in English. I Am trying study your site by google translator (OMG I feel sometimes like illiterate with this translator).

I just want to ask, if you use any diffusor with cross polarized light? How it looks? I would be happy if someone could describe / show it.

Best regards from Poland :)
Mirek

Welcome Mirek! :)

First of all: My apologies for the peculiar language on this site :)

To answer your question: Yes, I typically diffuse the light BEFORE polarizing it, when using the cross-polarization technique. It's very simple: just attach the polarizing film onto the flash diffuser. Beware of massive light-loss though! You may need to up your ISO setting significantly and/or use flash exposure compensation to compensate for this!

I use polarizing film from Edmund optics. It comes as a plastic sheet and you can easily cut it to fit perfectly in front of your flash diffuser. I've use several different solutions (to fit different diffusers). You can see one of them in this image: http://farm4.staticflickr.com/3431/3225700964_f3e1523daa_o.jpg

Thank you for the quick reply! :)

I really like to see photos of your setups, of course, in addition of your beaturiful macro photos :)
I use YN-565EX flash, which is quite strong, so it can not be bad with the loss of light (I hope). I just bought a linear polarizer that I can cut to the diffuser. I understand that one filter must be on the diffuser and the second on lens, right? 2nd. Filter on the diffuser must be specially installed? I ask because the circular filter on the lens I turn it to get the desired effect.

Yes, you need one polarizer on the diffuser and one in front of the lens. To achieve maximum cross-polarization effect their polarizing-directions should be crossed (perpendicular to each other) but you can easily vary the amount of the cross-polarization effect by turning the polarizer on the lens. If the polarizing directions are the same in both polarizers you will obviously have zero cross-polarization effect. In other words, the initial orientation of the flash-polarizer is not critical since you can always turn the lens-polarizer to your liking, but just to make things simpler to remember it's advisable to orient the flash polarizer either horizontally or vertically on the diffuser.

In this post you'll see a couple of cross-polarized images and in the movie clip you can see the cross-polarization-setup used at roughly 2:30: http://makrofokus.se/blogg/2012/2/22/ut-och-plata-vinterkryp.html

/John

11-14 | Registered CommenterAdmin

there was a small mistake - one polarizer on the diffuser and one in front of the LENS (not flash)*
Thank you John for the clarification, now I just have to get to work :)