Stacking Polarizers

FotoPete · 07-26-2007, 07:34 PM

I gotta thank MRRiley for suggesting this a while back for a neutral density effect if I remember correctly.

Today I got another polarizer and decided to try it out. I rotated the both until the viewfinder got really dark and dropped the aperture to about f8-11 and let the shutter open for 8 seconds. I was expecting some really contrasty image but ended up an infrared image!

I don't have my card reader at the moment but I'll post some samples tomorrow. The images come out all pink and white. Pretty kool and the foilage was all white.

So this is an extra incentive for those with a collection of polarizers. You get added contrast and reduction of distracting reflections during regular use. Stack them and you've saved yourself a Hoya R72 filter for infrared photography!

barendvl · 07-27-2007, 05:16 AM

Originally Posted by FotoPete

I gotta thank MRRiley for suggesting this a while back for a neutral density effect if I remember correctly.

Today I got another polarizer and decided to try it out. I rotated the both until the viewfinder got really dark and dropped the aperture to about f8-11 and let the shutter open for 8 seconds. I was expecting some really contrasty image but ended up an infrared image!

I don't have my card reader at the moment but I'll post some samples tomorrow. The images come out all pink and white. Pretty kool and the foilage was all white.

So this is an extra incentive for those with a collection of polarizers. You get added contrast and reduction of distracting reflections during regular use. Stack them and you've saved yourself a Hoya R72 filter for infrared photography!

That sounds like a very nice effect. I'm interested in your results. Too bad I only got one polarizer.. You are talking about circular polarizers, right? Not the linear ones...?

FotoPete · 07-27-2007, 02:57 PM

I checked and I think its linear polarizers. The polarized light coming through one is canceled by the following one. I didn't get a chance to get a good shot today so stay tuned!

MRRiley · 07-27-2007, 07:04 PM

Thats cool Pete. I hadn't noticed that effect personally but then I havn't tried it with them on quite that long an exposure. Will have to give it a try myself. Looking forward to seeing your results for sure!

oh, barendvl, it wouldnt matter if they were linear or circular except that if you mix them you should put the circular one closest to the lens. The actual "polarizer" layer is the same on both types but the circular ones have an additional layer on the inside which helps them work better with AF and the meters in modern cameras.

roy · 07-28-2007, 09:39 AM

Originally Posted by barendvl

That sounds like a very nice effect. I'm interested in your results. Too bad I only got one polarizer.. You are talking about circular polarizers, right? Not the linear ones...?

i've got several if you want one.

pete, i'll have to try this. time will tell.

MJB DIGITAL · 07-28-2007, 07:09 PM

tag tag tag tag

SupremeMoFo · 07-28-2007, 09:28 PM

Eeek! I'd have to buy another 77mm circ polariser for this... ouch... pass!

FotoPete · 07-28-2007, 10:28 PM

Ok just to clarify I used linear polarizers in this experiment. I had the intention of stacking polarizers to create an amplified ND filter effect but ended up with an infrared shot.

I got the chance to try out some more shots earlier today. This first one is taken with a 62mm PL, 62-52 step up ring and a 52mm PL stacked on a XR Rikenon 28/3.5.

There some colour spectrum change along the diagonal which I though might have been related to the filter size difference (62vs52) as I had not noticed this the first time I accidentally discovered it with 2 52mm PLs.

I went down to the camera store and got another 62mm.

62mm PL + 62mm PL Stacked.

62mm PL + 52mm PL stacked.

So you can see there appears to be a link between diagonal colour shifts and the differences in polarizer sizes.

While this maybe an interesting alternative to an actual infrared filter, its important to note that you'll need a tripod as these infrared photos require a few seconds of exposure time. Also, you might find a lens hood handy as the extra PL filters can cause some flare in your photo!

Mechan1k · 08-22-2007, 07:42 PM

Interesting indeed ... might have to try this out and have a look.
Need to grab another Pol filter though.

I like the effect though in these pics.

Entropy · 08-22-2007, 08:47 PM

Originally Posted by SupremeMoFo

Eeek! I'd have to buy another 77mm circ polariser for this... ouch... pass!

No. You would not have to buy a CP - a CP would not work for this purpose. (At least as the front polarizer, the back one could be a CP). You would need an oldskool linear polarizer.

Actually, you would have no problem with two LPs, as with that much light loss you won't be using automatic metering or autofocus.