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Anyone tried the Chinese IR filters
I am looking to try some infra red photography and have found that the price of a reputable 77mm R72 filter is around $300. Chinese ones are only around $30. I suspect that image quality will suffer with the cheap filter. Just wondered if anyone has tried them and what sort of results you got.
Any comments appreciated.
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Yes, I have the Chinese IR680 and IR720 filters in the 77mm size. The price is great and so far the optical quality looks fine.
Because I could see (sort of very faintly) through these filters when inspecting a sunlit landscape I though they may be useful with ordinary panchromatic film as well as IR film. Preliminary results on Fomapan 200 with the IR680 filter indicate a sunny day exposure of 8 minutes at f5.6 yields a rich negative. The IR720 filter also seems to need 8 minutes at f5.6. Is this because Fomapan 200 reaches into the IR or do the Chinese filters leak too much visible?
More experiments need doing!
Photography, the word itself, invented and defined by its author Sir John.F.W.Herschel, 14 March 1839 at the Royal Society, Somerset House, London. Quote "...Photography or the application of the Chemical rays of light to the purpose of pictorial representation,..". unquote.
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I haven't used them. I buy sheets of optically plane IR filter plastic from Edmund Scientific and cut it on my bandsaw. It has worked beautifully for me. They've changed their catalog, but I think this is it:
http://www.edmundoptics.com/onlineca...productID=1918
They are not as severe as the "real" IR filters, but I prefer less severe images. I like to have a bit of visible light record. This stuff is perfect for that; a really inviting kind of image, and the price is better than the Chinese ones, by far.
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If you find the Edmund filters interesting -- In the above, I forgot to mention that this filter material is extremely hard. I tried to score it and snap it. Don't do that! Flying shards went all over the place. I cut them with a bandsaw, paper rubber cemented to both sides, with the desired shape drawn.
Also, it is not advisable to keep them where they are in UV light when not in use.
They also make red, green, and blue filters in the same material. All are extremely tough and durable.
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I have a no-name R72 clone (about $50 for 77mm in 2006 on eBay), works beautifully. No softness issues unlike with my nasty generic CPL. It's uncoated as far as I know.
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I've got a 49mm 720nm filter that gives great results. I got if off eBay from a Chinese dealer for $20. I don't have a genuine R72 filter to compare it to, but I think the quality isn't much worse, certainly not in the light-blocking ability. You might, however, want to take extra measures to avoid flare.
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 Originally Posted by bowzart
I haven't used them. I buy sheets of optically plane IR filter plastic from Edmund Scientific and cut it on my bandsaw. It has worked beautifully for me. They've changed their catalog, but I think this is it:
http://www.edmundoptics.com/onlineca...productID=1918
They are not as severe as the "real" IR filters, but I prefer less severe images. I like to have a bit of visible light record. This stuff is perfect for that; a really inviting kind of image, and the price is better than the Chinese ones, by far.
hey bowzart,
is the red, green and blue filters similar to the types of filters that photographers usually use? like the red 25a, standard green, standard blue filters? or are they the filters used for color separations work, like the RED 25, non-a?
I'm not technical at all, and the whole wavelength chart thingie doesn't work for me, but since I'm a student, the costs of these 4"x5" filters are a great savings over traditional screw-in filters. I'm looking to get a LEE filter holder, so to use the 4x5" on the screw-in adapter eventually. along with ND-grads(for color/bw work).
thanks and merry christmas!
-Dan
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If you want a cheap IR filter a Cokin "P" series filter costs ca. 50 US Dollars. Quality is very good.
(Yes, I do have a tendency to ignore chinese products...)
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I wonder about ND filters. I've wanted to have a ND grad (screw mount) and nothing but Chinese is available below 20$; At least in 49mm size.
Common colored filters (81A, K2, etc) can be found used at a decent price being hoya, for example. But used screw mount ND grads seem to be hard to find.
Sometimes I forget about it, because I've got a good CPL. Polarizers darken the sky reducing contrast, but, not always.
The worst of that, is that one of these cheapies may give horrible flaring and ghosting and a wonderful color cast in the ND area. And, using them in a sunset with sun there, better not.
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