bpalme Posted May 17, 2011 Share #1 Posted May 17, 2011 Advertisement (gone after registration) Ok.. I've been experimenting around with this thing and can't really tell any difference. I've tried all kinds of angles from the sun. I have the UV/IR on underneath it if that makes any difference. It is a super clear day so may it doesn't make much difference when there is very little haze. Anyway I know it's the user...I'll keep messing around with it. Any advice for a newbie? Link to post Share on other sites More sharing options...
Advertisement Posted May 17, 2011 Posted May 17, 2011 Hi bpalme, Take a look here Leica Polarizer. I'm sure you'll find what you were looking for!
hoppyman Posted May 17, 2011 Share #2 Posted May 17, 2011 When you flip it up and look through the finder and filter, can you see the sky darken/lighten as you rotate the ring? Link to post Share on other sites More sharing options...
ho_co Posted May 17, 2011 Share #3 Posted May 17, 2011 The rule of thumb is that the blue sky is most polarized at an angle of 90° from the sun. That means if the sun is near rising or setting, greatest polarization will be to the north and south and straight overhead. If the sun is overhead, the greatest polarization will be near the horizon all around you. Try it first just by looking through the polarizer, as Geoff suggested. If you can see the effect, so can the camera. The UV/IR should be behind the polarizer, just as you've got it. If this is a used polarizer, be aware that the polarizing material does wear out. None of my polarizers from 30 years ago works today. Link to post Share on other sites More sharing options...
Guest #12 Posted May 17, 2011 Share #4 Posted May 17, 2011 try it on a reflection in glass Link to post Share on other sites More sharing options...
lars_bergquist Posted May 17, 2011 Share #5 Posted May 17, 2011 There is a sticky thread called 'Leica Camera FAQs (Frequently Asked Questions)' that does contain some info about what it's all about. Remember: all light is not polarised, and a polariser works only with polarised light. The slightly polarised old man Link to post Share on other sites More sharing options...
bpalme Posted May 17, 2011 Author Share #6 Posted May 17, 2011 When you flip it up and look through the finder and filter, can you see the sky darken/lighten as you rotate the ring?Yes The rule of thumb is that the blue sky is most polarized at an angle of 90° from the sun. That means if the sun is near rising or setting, greatest polarization will be to the north and south and straight overhead. If the sun is overhead, the greatest polarization will be near the horizon all around you. Try it first just by looking through the polarizer, as Geoff suggested. If you can see the effect, so can the camera. The UV/IR should be behind the polarizer, just as you've got it. If this is a used polarizer, be aware that the polarizing material does wear out. None of my polarizers from 30 years ago works today. Interesting There is a sticky thread called 'Leica Camera FAQs (Frequently Asked Questions)' that does contain some info about what it's all about. Remember: all light is not polarised, and a polariser works only with polarised light. The slightly polarised old man Thanks I'll look for that. I got a good link from someone over at DPR. If anyone is interested here it is: http://archive.popphoto.com/pdfs/2002/0902/Polarizer.pdf Link to post Share on other sites More sharing options...
tdtaylor Posted May 17, 2011 Share #7 Posted May 17, 2011 Advertisement (gone after registration) If this is a used polarizer, be aware that the polarizing material does wear out. None of my polarizers from 30 years ago works today. Thanks for this piece of information. Never realized that. Link to post Share on other sites More sharing options...
ho_co Posted May 17, 2011 Share #8 Posted May 17, 2011 The discovery was a shock to me as well, Terry! Link to post Share on other sites More sharing options...
leica dream Posted May 17, 2011 Share #9 Posted May 17, 2011 I have just been on a photography course and when we covered polarizers the guy got us to shoot crumpled cellophane and cracked or stressed CD/DVD cases. Apparently, Industry uses polarizing technology to look for faults in perspex type items. We got some stunning shots but I have unfortunately not saved mine so I cannot show you the proof. It did prove to us the power of polarizers. Richard Link to post Share on other sites More sharing options...
Xmas Posted May 17, 2011 Share #10 Posted May 17, 2011 The stress detection using polariod will work with optical glass as well. When my specs cracked in glasses case the supplier replaced them and said it was not my fault, they had been stressed during mounting... Leica probably use the same technique in manufacture. You can use the polariod to shoot through window glass in shops, with reduced reflection. Noel Link to post Share on other sites More sharing options...
Washington Posted May 18, 2011 Share #11 Posted May 18, 2011 Howard, I too have never heard that polarizers wear out. That is news to me. Do you know why??? Link to post Share on other sites More sharing options...
ho_co Posted May 18, 2011 Share #12 Posted May 18, 2011 I may be crazy, Rip. All I know is that I've got a Leica swing-out polarizer that doesn't polarize, and a B+W Käsemann polarizer that doesn't polarize. I know that polarizers are a sandwich with a piece of glass on each side of the polarizing material, but what that material is or how it could degrade I don't know. Sorry. I'd like to know, myself. Link to post Share on other sites More sharing options...
Washington Posted May 18, 2011 Share #13 Posted May 18, 2011 Daw gone… I had no idea. I do have some pretty old ones here, including Leica 39mm swing out… I best take a look!!!! Thanks! Link to post Share on other sites More sharing options...
ho_co Posted May 18, 2011 Share #14 Posted May 18, 2011 And let us know how they work. Link to post Share on other sites More sharing options...
tdtaylor Posted May 18, 2011 Share #15 Posted May 18, 2011 I happen to have a swing out and typical Leica polarizers. One looks rather old, but still works. I don't know how to tell how old. I do know the polarizing material is crystals that are aligned to allow wavelengths in one orientation to pass through the filter. Beyond that, I have no idea why a crystal would stop working. Inquiring minds would like to know Link to post Share on other sites More sharing options...
ho_co Posted May 18, 2011 Share #16 Posted May 18, 2011 Maybe I'm wrong, Terry. Maybe my perceptions have been dimmed by searching for Haidinger's brush. I'll assume I'm wrong unless someone tells me my chewing gum can't lose its flavor on the bedpost overnight, or polarizing foils their polarizing nature. Polarizing thought, isn't it? Either they do or they don't. Link to post Share on other sites More sharing options...
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