PNad
Leading Member
Does this entirely remove reflections? Rosco makes some polarizing gels and some glasse's coating are really really reflective, would using the gels with a circular polarizer on my lens remove it?
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Polarizing gel on flash + circular on lens for glass reflections
- Thread starter PNad
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SKersting66
Senior Member
I would say it's a solid "maybe." It should work but it may not be as easy as it seems. The problem is that if the light is polarized and it passes (reflected) thru anything non-conductive (i.e. clear plastic) you will get weird colors due to cross polarization.
Ellis Vener
Forum Pro
Are you photographing glass or a glass covered object.
In general yes cross-polarization will eliminate 99% of your glare issues. Cross polarization means that the polarizer a are oriented so that the polarization axis for the gel and the filter are at ninety degrees to each other.
Smooth Glass, because it is a very efficient reflector, will still have direct reflections of light sources.
Want to try an experiment? Use cross polarization when shooting a portrait.
PNad
Leading Member
I dont want to buy a $200 roll to try the portrait experiment, this is why I asked in this forum. I want to know if it will remove reflection from people's glasses.
Yes Its about the angle of incidence, but this my question still remain.
Ellis Vener
Forum Pro
I dont want to buy a $200 roll to try the portrait experiment, this is why I asked in this forum. I want to know if it will remove reflection from people's glasses.
Ah! The plot thickens - you said glasses and it wasn't clear (to me at least) that you meant eyeglasses on someone's face.
The problem with cross polarizing light and portraits is that the skin will look really weird as you'll remove all natural sheen on their skin.
The solution to your problem is indeed an angle of incidence solution. You need to either move your light to a different angle or have your subject turn slightly away from the light. Either approach increases the angle of incidence.
In the attached portrait of my assistant, I used two light sources he light sources here are
Key light (from the left): An Einstein E640 in a medium Chimera SuperPRO light bank, behind a 6 x 6 foot, 1/2 stop Chimera scrim
Fill: (from the right): A second Einstein with a Phottek Goodlighter and diffuser, behind a 4x4-foot Chimera 1/2 stop scrim.
Ah! The plot thickens - you said glasses and it wasn't clear (to me at least) that you meant eyeglasses on someone's face.
The problem with cross polarizing light and portraits is that the skin will look really weird as you'll remove all natural sheen on their skin.
The solution to your problem is indeed an angle of incidence solution. You need to either move your light to a different angle or have your subject turn slightly away from the light. Either approach increases the angle of incidence.
In the attached portrait of my assistant, I used two light sources he light sources here are
Key light (from the left): An Einstein E640 in a medium Chimera SuperPRO light bank, behind a 6 x 6 foot, 1/2 stop Chimera scrim
Fill: (from the right): A second Einstein with a Phottek Goodlighter and diffuser, behind a 4x4-foot Chimera 1/2 stop scrim.
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SKersting66
Senior Member
It will work for the glasses... I don't know if a lack of sheen from skin is an issue, that seems like it would be ok to me. But I haven't used it for portraits; it will also cost about 3 stops of light.
PNad
Leading Member
Im a big fan of this lighting setup. Yes it was lately popularized by Peter Hurley and im straight on using "his" technic, but in the end thats what we all do anyway (using someone else thing). Back on topic, this is 3 softbox aimed directly at the face (for this photo I actually used a beauty dish, ence the round bottom catchlight) The problem is, some eyeglasses get some heavy reflection from the bottom light, and I really love that triangle catchlight. So I thought of putting a polarizing gel on the bottom softbox.
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Ellis Vener
Forum Pro
try it and tell me what you think.its not like using matte makeup, it's more like the light penetrates the skin.
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Sailor Blue
Forum Pro
If you can't get the light into a position where reflection off of grasses isn't a problem you can try raising the earpieces a small amount. This tips the lenses down a bit and changes the angle of reflection for a light.
To get the best results in reducing polarized reflections you want to use crossed linear polarizing filters.
I suggest you see if your local library has a copy of Light Science and Magic. The section on polarized reflections starts on page 41.
Amazon.com - Light Science and Magic, Fourth Edition: An Introduction to Photographic Lighting (9780240812250): Fil Hunter, Paul Fuqua, Steven Biver: Books
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Living and loving it in Pattaya, Thailand. Canon 7D - See the gear list for the rest.
To get the best results in reducing polarized reflections you want to use crossed linear polarizing filters.
I suggest you see if your local library has a copy of Light Science and Magic. The section on polarized reflections starts on page 41.
Amazon.com - Light Science and Magic, Fourth Edition: An Introduction to Photographic Lighting (9780240812250): Fil Hunter, Paul Fuqua, Steven Biver: Books
--
Living and loving it in Pattaya, Thailand. Canon 7D - See the gear list for the rest.
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PNad
Leading Member
I think it may be more about the specular hightlights. The cross polarization probably removes it and it ends up looking super flat?
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PNad
Leading Member
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SKersting66
Senior Member
If you only cross polarize one light, then I don't think the effect on the skin will be extreme. But yes, if you remove the reflection from the glasses it will also affect the catchlight.
A common trick is to simply remove the lenses from the glasses... this also eliminates the face-line "jump" that can happen with many prescriptions. You can always ask them to bring an old pair to work with if they have suitable ones.
BTW, the reflected light from glass is already polarized, a CPL should be able to remove much of it. (And it would also affect the other reflections in your one filtered light setup idea).
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https://www.flickr.com/photos/skersting/
A common trick is to simply remove the lenses from the glasses... this also eliminates the face-line "jump" that can happen with many prescriptions. You can always ask them to bring an old pair to work with if they have suitable ones.
BTW, the reflected light from glass is already polarized, a CPL should be able to remove much of it. (And it would also affect the other reflections in your one filtered light setup idea).
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https://www.flickr.com/photos/skersting/
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SKersting66
Senior Member
Being that I don't really do portraits, I'll take your word for it... I've seen the effect on plants.
SKersting66
Senior Member
If you use a linear filter on the lens it will (potentially) adversely affect AF/viewing.
A CPL *is* a linear filter with a quarter wave plate. The quarter wave plate ensures that some light will pass thru the pellicle mirror portion to the AF sensor, and that some does not and gets to the eyepiece.
PNad
Leading Member
SKersting66
Senior Member
Yes, anytime light is reflected from an absorptive surface (water,glass,paint,etc) it is polarized. In fact, all light is polarized to some minor extent simply due to passing thru the air. Surfaces that do not absorb/pass any light (metal,mirrors) do not add additional polarization. How much the light is polarized will determine how effective a CPL is (you may not be able to completely remove the reflections...and it will affect the catchlights as well).
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https://www.flickr.com/photos/skersting/
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https://www.flickr.com/photos/skersting/
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PNad
Leading Member
I am 100% confident that a single CPL on a lens wont remove direct flash reflections. And to support my point, heres a behind the scene with product photographer Rob Grim:Yes, anytime light is reflected from an absorptive surface (water,glass,paint,etc) it is polarized. In fact, all light is polarized to some minor extent simply due to passing thru the air. Surfaces that do not absorb/pass any light (metal,mirrors) do not add additional polarization. How much the light is polarized will determine how effective a CPL is (you may not be able to completely remove the reflections...and it will affect the catchlights as well).
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https://www.flickr.com/photos/skersting/
Why he would bother using the gel on the strobe if a single CPL would work?
Anyway, this solution is a no go since it removes the catchlight, ill just keep turning off the middle bottom flash when particular eye glasses reflect too much.
SKersting66
Senior Member
Because he's using the gel on a secondary light in order to get it to match the other light the CPL is adjusted for... that's why he has to adjust/turn the gel on the light, and not the CPL.
A CPL has a limited angle of where it is effective...if the lights are coming from different angles/areas it will probably not be equally effective on all of them. But it can/will work for strobes.
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