Wrote a quick blog post on filters

jcdoss · 12-10-2016, 08:53 AM

Excellent post, and your photos look really nice. I'd never heard of 'enhancing' reflections with a polarizer. Also, I wanted to ask if you were using a modified sensor for your IR shots? Which camera were you using? Have you tried UV/IR filters? Hope to see more!

photoptimist · 12-10-2016, 11:13 AM - **1 Like**

Originally posted by jcdoss

Excellent post, and your photos look really nice. I'd never heard of 'enhancing' reflections with a polarizer. Also, I wanted to ask if you were using a modified sensor for your IR shots? Which camera were you using? Have you tried UV/IR filters? Hope to see more!

Yes, a polarizer can be used to brighten a reflection. Simply rotate the filter until the reflection looks as dark as possible and then rotate it another 90° exactly.

The effect is subtle in the viewfinder but is visible in side-by-side photos. It works because the filter is also attenuating every non-polarized part of the scene by 50% but not attenuating polarized light that aligned with the polarizer. That is when the filter is mounted, the scene gets darker, but reflections at the selected angle do not so they become relatively brighter.

You can also use this trick on scenes with segments of rainbows (which are strongly polarized). It's great for rainbow shots at normal & telephoto focal lengths but not UWA because the polarization angle varies along the arc.

**lithedreamer** · 12-10-2016, 11:30 AM - **1 Like**

Originally posted by jcdoss

Excellent post, and your photos look really nice. I'd never heard of 'enhancing' reflections with a polarizer. Also, I wanted to ask if you were using a modified sensor for your IR shots? Which camera were you using? Have you tried UV/IR filters? Hope to see more!

Yeah! I had a project in school, shooting reflections with film, and a polariser was very useful. I attached a couple examples to this post. For my IR shots, I haven't used a converted sensor, just an R72 Hoya filter (~$80). Most of my IR work was done with my older but very reliable Pentax K-30. The main benefits I see to camera conversion are easier composition (though Xume rings can certainly help as a stop-gap) and faster shutter speeds. You're liable to get blurred leaves if there's even a little wind, for example.

I've also had a minor project/obsession of trying to shoot with IR filters over my flashes, because I've seen some amazing things done with that, but no one has actually explained to me how it's done. Here's a link to some examples I found on someone else's blog, but they've made it very clear that they're not sharing. :/

jcdoss · 12-10-2016, 03:06 PM

Thanks for the info, photoptomist and lithedreamer! I think I'm gonna get a set of Xume rings and try out some IR shots. B+W makes a IR/UV filter that's supposedly sensitive mostly to UV, but isn't opaque to IR. I will have to read up on that one too. How often do you use your 10 stop ND? Is it better than using a multi-exposure? Thanks for this thread and your blog post!

**lithedreamer** · 12-10-2016, 03:19 PM

Originally posted by jcdoss

Thanks for the info, photoptomist and lithedreamer! I think I'm gonna get a set of Xume rings and try out some IR shots. B+W makes a IR/UV filter that's supposedly sensitive mostly to UV, but isn't opaque to IR. I will have to read up on that one too. How often do you use your 10 stop ND? Is it better than using a multi-exposure? Thanks for this thread and your blog post!

Hmm. Let me know how the UV sensitive filter goes, I've seen some cool work done with UV and portraiture. I use my 10 ND filter quite a bit, and have actually tried comparing it to multiple exposures. I love multiple exposures for blending different frames together, but I've found it too fiddly for ND-replacement work. On the other hand, I'm not entirely confident in my multiple exposure method thus far. I'll do some more work and get back to you with a clearer answer in another blog post.

Thanks for reading!

12-10-2016, 11:13 AM - 1 Like	#17
photoptimist Pentaxian Join Date: Jul 2016 Photos: Albums Posts: 5,128	Originally posted by jcdoss Excellent post, and your photos look really nice. I'd never heard of 'enhancing' reflections with a polarizer. Also, I wanted to ask if you were using a modified sensor for your IR shots? Which camera were you using? Have you tried UV/IR filters? Hope to see more! Yes, a polarizer can be used to brighten a reflection. Simply rotate the filter until the reflection looks as dark as possible and then rotate it another 90° exactly. The effect is subtle in the viewfinder but is visible in side-by-side photos. It works because the filter is also attenuating every non-polarized part of the scene by 50% but not attenuating polarized light that aligned with the polarizer. That is when the filter is mounted, the scene gets darker, but reflections at the selected angle do not so they become relatively brighter. You can also use this trick on scenes with segments of rainbows (which are strongly polarized). It's great for rainbow shots at normal & telephoto focal lengths but not UWA because the polarization angle varies along the arc. Last edited by photoptimist; 12-10-2016 at 03:53 PM. Reason: typo

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12-10-2016, 08:53 AM	#16
jcdoss Pentaxian Join Date: Nov 2012 Location: Ingelheim am Rhein, Germany Photos: Gallery \| Albums Posts: 6,801	Excellent post, and your photos look really nice. I'd never heard of 'enhancing' reflections with a polarizer. Also, I wanted to ask if you were using a modified sensor for your IR shots? Which camera were you using? Have you tried UV/IR filters? Hope to see more!

12-10-2016, 03:06 PM	#19
jcdoss Pentaxian Join Date: Nov 2012 Location: Ingelheim am Rhein, Germany Photos: Gallery \| Albums Posts: 6,801	Thanks for the info, photoptomist and lithedreamer! I think I'm gonna get a set of Xume rings and try out some IR shots. B+W makes a IR/UV filter that's supposedly sensitive mostly to UV, but isn't opaque to IR. I will have to read up on that one too. How often do you use your 10 stop ND? Is it better than using a multi-exposure? Thanks for this thread and your blog post!

12-10-2016, 03:19 PM	#20
lithedreamer Site Supporter Join Date: Sep 2013 Photos: Gallery \| Albums Posts: 1,799 Original Poster	Originally posted by jcdoss Thanks for the info, photoptomist and lithedreamer! I think I'm gonna get a set of Xume rings and try out some IR shots. B+W makes a IR/UV filter that's supposedly sensitive mostly to UV, but isn't opaque to IR. I will have to read up on that one too. How often do you use your 10 stop ND? Is it better than using a multi-exposure? Thanks for this thread and your blog post! Hmm. Let me know how the UV sensitive filter goes, I've seen some cool work done with UV and portraiture. I use my 10 ND filter quite a bit, and have actually tried comparing it to multiple exposures. I love multiple exposures for blending different frames together, but I've found it too fiddly for ND-replacement work. On the other hand, I'm not entirely confident in my multiple exposure method thus far. I'll do some more work and get back to you with a clearer answer in another blog post. Thanks for reading!