Topic: Neutral Density Filters.??

[Cactus]

hey now, in my new explorations of camera ive come across these filters. just curious if anybody has or does use them?? if so do you recomend 2x or 4x?? im interested in them for the use around waterfalls/rivers to give the "movement" effect.. thanks in advance

[jpschust]

if you are looking to give your waterfalls movement effect just shoot at a speed below 800 and you will see it.   i just shot a few in Costa Rica.  Beware, it can be very dark around a lot of waterfalls.  much darker than you would think

[MattD]

Can't this type of filter be simulated pretty well in PS if you have multiple exposures (or 2 differently "exposed" RAW conversions of the same file)?

[jpschust]

im telling you, a regular shutter speed is going to capture water as its moving, not freeze framed.  water moves exceptionally fast down a waterfall.  as a matter of fact about 10m/s isnt that the gravity calculation?

[dmonterisi]

cactus, you are right that you will need a ND filter to create that cotton candy effect on flowing water.  in bright daylight, even at the smallest aperture, you will not be able to expose properly and keep the shutter speed as slow as you will need.   for the full-effect, you need shutter speeds of 1/2 second or a second or even slower.  in daylight, you will need a ND filter to get shutter speeds that slow.  4x couts out an awful lotta light, i'd go with the 2x for now.

matt-you're thinking of a grad ND effect being simulated in pshop.  a regular ND cuts the light uniformly, while a grad only affects half the frame (for example, shooting right at sunrise or set when the sky would be much much brighter than the ground).  you can mimic that effect by creating two different exposures and combining them in PS with a layer mask, but that's way beyond this question.  here, he just wants to cut the amount of light down so that he can use a slower shutter speed, not to balance the different brightness levels of different parts of a scene.

damon

[jpschust]

in just thinking about the waterfalls i have been to in my life, and ive been to a few, though there are a lot out there, they tend to rarely be in areas of extreme brightness and more often than not tend to be in areas where it is TOO dark.  What kind of area are you going to shoot in?

The only exception to waterfalls that I have seen where I've gotten a tremendous amount of light has been in Hawaii and even then I was able to slow down enough to make it work.

[rerem]

A Graduated ND may be of use,Kodachrome and a tripod are good,you can ose a soft release extension,set at about 1/15 sec,just a ND won't do anything slower film can't