Polarising Light in Studio Photography

Polarising studio light can be incredibly useful in commercial photography. But you have to know why, when and how to do it.

This knowledge will equip you with an extra level of control, which is particularly useful when shooting reflective or shiny surfaces, or even shots with multiple surface textures.

In this class, Karl explains what polarised light is and demonstrates how it works through three different practical shoots. He explains the difference between polarising your light and polarising the lens, what each does, and what happens when you do both.

In the class:

  • What is polarised light
  • How to polarise light
  • Cross polarisation
  • The difference between polarising light and polarising the lens
  • Linear vs circular polarisers
  • Polarising metal

Questions? Please post them in the comments section below.

Comments

  1. Hello Karl,
    Thank you for another excellent demo about depolarisation of a light stream. Besides applying a depolarising filter and check whether it is applicable or not is there a method to figure out beforehand whether the surface material we are dealing with on a case to case basis can be depolarised or not? Can we ascertain that the light bouncing off all surfaces that produce an image forming reflection (mirrors, metals, etc) cannot typically be depolarised?

    Thank you.

    1. Hi Myles, yes in nearly all gloss surfaces, except for bare metals, you can assume that using a depolarising filter will work. Of course remember that the filters themselves are known as polarising filters even though they de-polarise!

      1. Thank you Karl. One more query would be in the third example of light depolarisation can we also say that is also another example of cross polarisation since you employed two depolarising filters (one linear and one circular)? The only difference would be that in the second example you eliminated two wavelengths of the spectrum on a surface and not straight from the light source whereas the second you eliminated all both wavelengths from its source hence the reason of no light at all? Thanks

        1. Hi Myles, do you mean when I lit the items from underneath? Please keep in mind to note down the time in the video so I can check where you mean as I’m unable to remember everything in each class i’m afraid as we produce so many! If I’m correct with part you mean then I can’t remember if I was using one linear and one circular but that wouldn’t have effected it, I could have been using both linear (one on the light and one on the camera) and the result would have been the same.

          1. Thanks for the timely response, Karl, and apologies for not indicating the timestamp as a reference.
            In the second example of the shiny cleaver surface at 36:54 you show the use of a linear filter on the light source in conjunction with a circular one applied to the camera lens. You mention that this approach known as cross-polarisation is necessary to control reflections on certain material such as bare metals. However in this instance we are using cross-polarisation on the light bouncing off a surface and not straight from its light source therefore the result is the mere light hiding underneath and not reacting to that surface in the form of reflection due to its wavelength. At 1:09:10 however you show actually not only how the cross-polarisation works on materials other than metal but also straight from its light source (a softbox pointing upwards in that case).
            My question is can both these second and third applications be considered an instance of cross-polarisation due to the fact that you employ two depolarising filters at the same time although with different materials (metal in the second example and plastic in the third)?
            Also, if in your second example of the cleaver you pointed your camera along with the circular polariser applied to the lens to the light source which is also depolarised since you were using a linear filter would you have obtained the same results of a black frame where the softbox is?
            I hope I explained myself clearly this time.
            Thank you.

          2. Hi Myles, sorry for the late reply I’ve been tied up on a few jobs. So first of all don’t worry about whether the filters used were ‘circular’ or ‘linear’ type polarisation as the results would be the same. On the meat cleaver the if there had been no polarising filter on the light source then it would not be possible to remove any reflection of light with just a filter on the camera because the way bare metal interacts with photons means there would have been no polarisation happening to be able to ‘depolarise’ through the camera filter. By putting the filter on the light then we are forcing the light on the bare metal to be somewhat polarised and then allowing the filter on the camera to have some effect. In any example where we have the light and camera with filters then yes we call this cross polarisation. In your final question if I had pointed my camera at the light source for the meat cleaver would the result have been the same as the softbox version the answer is yes the light source would have gone black but maybe not totally as the light would have been much brighter and these filters don’t always block out everything based on the intensity of light. Cheers Karl.

  2. Thank you Karl for sharing your passion and knowledge with us through this platform! It is by far the best investment I’ve made this year!

    May I know for the Kenko extension tubes, which size do I need to get? They sell it separately as well as a set and I’m not sure which one is needed. I shoot with a Canon 6d mark ii.

    1. Hi, it depends entirely on how much magnification you need but I don’t think the set is much more expensive? If I had to choose then the thinest one is the one I use the most.

  3. As far as I remember from my lessons in Physics, a polarizing filter is created through a series of parallel lines or fibers running in one direction in the filter; its direction. By placing this filter in front of a light source you polarize the light by only allowing the light to pass through that is going in the same direction. By placing a second polarizer on the lens.. which is receiving the light, you can modify the lens polarizer filter lines so they are perpendicular to those coming at the lens. If you completely polarize the light, setting the filters perpendicular to each other, as exemplified perfectly by your table top straight down plastic shot, you get complete polarization. As I understand, a circular polarizer has two polarizing filters built together and you are rotating one from parallel to perpendicular and back again to parallel to adjust how much is applied. They are more expensive because you have two filters built in. .. I always assumed they are called circular because you rotate them, but that seems to confuse people. A linear filter is just a single layer of polarizing material.. for full polarization you need a second one.

    Excellent demonstrations of polarization control. I have been trying to source out large linear sheets for lights. They can be pricey.. There are some scientific ones I have found, but I haven’t yet taken the plunge on the purchase. Thanks Karl.

    1. Hi Gary, almost correct apart from the part about the circular polarisers, they aren’t two layers of glass that are seperated they simply use a different method of polarisation, based more on a spiral blocking rather than linear. The sheets I were using were LEE ones.

  4. This is an excellent subject to talk about and I appreciate the effort it takes to explain the science and the effect of polarization in this video. I feel like this is could be that “aha!” moment to bring up my photography to the next level. Thumbs up emoji.

  5. I don’t know how to thank you Karl for this extremely useful workshop, and I don’t how to describe my happiness for joining your online education center…

    Thank you for everything!

  6. Loved the session, very informative and I learned a lot already. I knew about polarizers and have used them but never in the light source, main take away for me. Your grace in answering some of those questions is saint-like. I’m new to your course and look forward to the rest of the program. Thank you Karl.

  7. Great tour of how to make and use polarised light Karl – really enjoyed watching that. Incidentally – LCD screens are a usable source of polarised light (as long as you need a flat panel of light): I took this handheld test shot 10 years ago using a Samsung LCD monitor as the light source – using the exact same technique Karl used on the last set-up in the video. I just made a pure white image in Photoshop and displayed it full-screen.

    https://www.flickr.com/photos/owenlloyd/4906108282/in/album-72157624369237082/

    They are very dim of course. But that shouldn’t matter if everything is locked down in a dark room and there’s no movement involved. I’ve never used this for anything since though :-/

    Just ordered a new sheet of polarising gel (from Stage Gear in the UK) Rosco 730011 is the code for it. The Lee code is 239

  8. For many years I was going to do shots like the last set up.. This course refreshed some infos for me and added more in great details. As always, thank you so much I appreciate all your efforts as well as the team behind you.. Be safe!

  9. Hi Karl. In my product shots accurate colour is really important. When you polarize the light the overall colour appears to change. How do I correct the polarised image so that the product still looks the correct colour.

    1. Hi, technically the colours aren’t changing, they were always there they were just being obscured by the polarized light. However I do understand what you mean, essentially we end up with colours that look more saturated so it would make sense that a little desaturation would bring them back to a perceptual perspective.

  10. FYI, Fotodiox makes extension tubes for the X Series of Hasselblad cameras which also provide electric connections for metering and focus etc. They work quite well.

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