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My today's fighting against polarising filter

Posted 01/04/2013 - 06:54 Link
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Rubbing a lead pencil on the threads is a superb idea. But please do this first:- Wipe the threads with an old clean hanky pressing your nail into the threads. You will be surprised to find some dark scum on the threads. Then spray some WD40 on the hanky and clean the threads again. Note: your hanky may tear, so use an old one.
I have a kitchen tool for $ 3 or 4, for opening Jar caps. Any filter from 100 mm dia to 20 mm can be opened easily - see photo. It has a soft rubber insert which can be removed if needed. See photos attached.
Just ensure your filter screws in smoothly w/o applying too much pressure - sign of a good filter thread.
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Daniel Bridge
Posted 02/04/2013 - 22:32 Link
droopsnoot wrote:
I bought an 86mm CPL filter for my Sigma 50-500, just one from eBay, not the cheapest but relatively cheap, and that was quite poor in how it screwed on to the lens. When I tried it at the weekend I also found that it affected focus quite badly, whether that was because it's rubbish, or because it wasn't on properly, or some other reason, I don't know.

Any thoughts on why it affected focus so much?

I've seen several filters, mainly cheap UVs, but one polariser, that affected the focus, or simply softened the image. It's one of the first things I'll look at if someone's having problems with getting a sharp shot. I presume they're just too cheap, and the glass isn't properly formed.

K-3, a macro lens and a DA*300mm...
Posted 02/04/2013 - 23:52 Link
Images of shooting with a marigold glove on one hand comes to mind. Worth a try out here as it would probably have the Canon shooters scrambling to the shops as they would feel left out.

Best regards
Inspiration is rarer than a plate glass camera.....

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