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-   -   Looking for Variable Neutral Density filters? (https://www.dvinfo.net/forum/open-dv-discussion/64394-looking-variable-neutral-density-filters.html)

Wayne Morellini April 5th, 2006 06:48 AM

Looking for Variable Neutral Density filters?
 
I am looking for Variable Neutral density filters. These are things where you can select the density your want, even on the fly.

I am interested in what variety is out there, anybody know?


Thanks

Wayne.

Andrew Khalil April 5th, 2006 12:30 PM

I've never used them, but I've heard that the ones sold here are really good:
http://www.singh-ray.com/varind.html

Doug Boze April 5th, 2006 01:37 PM

You can make one yourself from a pair of polarizing filters. When they are in congruence, they'll have twice their filter factor, and a 90-degree twist will block all light. Downside is not knowing the exact reduction at any point between, but you could guestimate it and use a metallic Sharpie to mark the points of min and max and in-between.

Wayne Morellini April 5th, 2006 03:15 PM

Thanks for the replies guys. Yes, I remember it when I had a look at the one above (it even says that it will work with anything but polarisers). I am still interested in seeing what other solutions are available, as even the best polarisers I've seen kill a lot of light. I would like to find something that is almost clear, so it can be left on the camera in all conditions, as I walk around.

I've had a few ideas in times past on how to make one, but they are complex, or sloppy, a good manufactured product would be nice.

Andrew Khalil April 5th, 2006 03:36 PM

If you're looking for something that doesn't kill light, neutral density filters aren't what you need. If you simply want to protect the lens, get a UV filter but remember there are situations you'll need to remove it or it will affect your image which is why I personally don't like them.

Wayne Morellini April 6th, 2006 06:04 AM

I still want a ND like reduction, but something you can turn down to nearly 0 ND, so I can walk into a low light situation without having to ever remove it. Once you get below 50% light loss, polarisers cost heaps too. I think the one above is two 50% polarisers because of the two stop loss minimum. I think I might have a solution for a polariser that can have light loss of much less than 50% hopefully down to less than 10%, but unfortunately I haven't got the ability or equipment to design it. It was a solution to another problem I was thinking of today.

Anyway, so are polarisers the only solution out there?


Thanks

Wayne.


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