How can I take a longer exposure in daylight, without blowing out the picture completely? I have messed with a combination of settings, but I cant get it right.
*edit: typo on the title...ANSWER instead of image*
Neutral density (ND) filters. "Neutral density" just means it's not colored - that is, it's gray.
They're often marked in terms of how much they cut the light. For example, my 4x ND filter cuts the light to 1/4 of actual, allowing me to quadruple the normal exposure time.
You can stack them, which multiplies the effect, so a 4x on top of a 2x yields 8x, or 4x and 8x yields 32x.
You can also stop down, using a smaller aperture (larger F-number).
Those two together are how I took this shot in early morning but still got a long exposure so the water blurred:
You can stack them, which multiplies the effect, so a 4x on top of a 2x yields 8x, or 4x and 8x yields 32x.
Is this true? If you stack a 1x on a 2x, don't you get an equivalant of 3x? Therefore a 2x on a 4x would be a 6x, not 8x?
Careful - there's "x" ratings and there's "density" ratings. "x" indicates the actual multiplier, not the number of stops. So 4x means 1/4 of the light. But a 1-stop filter means 1/2 the light.
x multiplies, stops add.
2x + 4x yields 1/8 the light.
1 stop + 2 stops yields 3 stops, which is also 1/8 the light.
Careful - there's "x" ratings and there's "density" ratings. "x" indicates the actual multiplier, not the number of stops. So 4x means 1/4 of the light. But a 1-stop filter means 1/2 the light.
x multiplies, stops add.
2x + 4x yields 1/8 the light.
1 stop + 2 stops yields 3 stops, which is also 1/8 the light.
Ah-ha! There we go. I have stopped ND filters. Thanks for the clarification.
-drew
I have habit of spelling them colour, neighbour etc etc, and my spellcheck keep telling me spelling error. Its irritating.
You can add the words with the English, UK spelling to the dictionary of the application you are using and avoid those warnings.. I have even added my name, company's name etc to my custom word dictionary to avoid those irritating messages.
