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Old Sep 4, 2007, 7:04 PM   #1
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Back when I first got an autofocus SLR I was told I needed a circular polarizer. I believe the reason had something to do with the auto focus. Now I have K10d and use both the kit lens and many of my older manual focus lenses. Is there any reason I shouldn't be using my old linear polariizer with the manual focus lenses?
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Old Sep 4, 2007, 7:15 PM   #2
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Just two points, first of all if you focus using the focus screen then the AF system is not an issue, but if you depend upon the in-focus signal then you may get focus errors with the linear polarizer. Just test it out and see what happens.

Secondly I am not certain if a linear polarizer will have any impact on the metering system, again, test to find out.

I have used linear polarizers with my DS without any obvious errors but they may just escape my less-than-perfect eye.

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Old Sep 4, 2007, 10:03 PM   #3
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The only polarizer I have is a linear one (bought back in my ME days). I've had varying success with it. Sometimes you can get the AF to work fine, but sometimes it will hunt and not find a lock (my only AF lens with a 49mm thread is the Phoenix macro, and it's AF mechanism is pretty flaky anyway). I didn't have much trouble with exposure when using an SMC M50mm 1.7 lens and a K100. I've had more trouble with exposure with the K10, but haven't tried it since I upgraded to firmware 1.30, which seemed to fixthe manual lens metering trouble I was having without a polarizer.With the Phoenix lens the exposure is more hit-or-miss. If you already have one, give it a try and see what kind of results you get.If you don't already have one, get the circular polarizer because I've found the linear isn't always reliable (fine for messing around but I wouldn't want to depend on it).
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Old Sep 5, 2007, 3:32 PM   #4
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i recommend these guys. never had a prob and prices are good.


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