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Old Aug 22, 2003, 4:42 AM   #1
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Default ND filters

im looking for some nd grad filters and when looking saw some grey grad and was wondering if this is the same?
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Old Aug 22, 2003, 5:56 AM   #2
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Yes, it's the same... Grey is the neutral color, although they come in other colors and are called graduated filters and not ND.
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Old Aug 22, 2003, 6:53 AM   #3
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ah thanks i thought so but didnt want to go and buy the wrong filter!
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Old Aug 22, 2003, 1:26 PM   #4
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NHL, I thought I understood this, but had to read your post a couple of times. Is my understanding as follows correct:

A neutral density filter is a grey filter which attenuates all colour in RGB equally. I.e it does the same job as shutting down the iris or increasing the f stop. The filters come in different values of density or greyness, darker or higher the light attenuation, the higher the ND number.

A graduated ND filter is a special animal consisting of a density ( or greyness) which changes gradually from the top of the filter to the bottom. Its purpose is to offer a greater attenuation to say the top third of the frame, compared to the middle and bottom to prevent over exposure of the background, e.g sky in a landscape pic. The gradual change of density is supposed to be such that the resulting pic still looks natural, but allows the limited dynamic range of a camera to produce good foreground exposure, whilst not burning out the sky background.

Usually, with people shots this problem is overcome by stopping down ( to reduce background light) and using fill flash on the subject. But with landscape scenes the flash would have to be super enormous to light the foreground correctly

I just wanted to clarify the point, that a 'grad' or graduated filter is really a special effect version of the plain ND filter. Is this Correct? VOX
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Old Aug 22, 2003, 4:34 PM   #5
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Quote:
I just wanted to clarify the point, that a 'grad' or graduated filter is really a special effect version of the plain ND filter. Is this Correct?
VOX, You've got it! Every you say is correct and for that special effect: http://www.cokin.com/ico8-p20.html

... and you also have this kind which changes color as it's polarized, if you want to be creative (not that Photoshop's Gradient tool can't do the same):
http://www.bhphotovideo.com/product/...OP171/REG/4032

What color do you fancy?
http://www.geocities.com/cokinfiltersystem/id215.htm

:lol: :lol: :lol:
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