Which ND Filter?

sactown024 · Oct 11, 2012

I am looking to play with long exposures on sunsets and waterfalls etc...

can someone point me in the right direction for a good filter that will allow me to do this?

KmH · Oct 11, 2012

* Thread Moved *

A lot of people get a stackable ND 3 filter set, like a 0.3, a 0.6 and a 0.9.
Stacked you then also have a 1.2, a 1.5 and a 1.8.

Plus they get the filter set with a thread size that is as big as their largest required lens filter thread size and use a step-down ring so they can use the bigger than needed filters on smaller lenses.
Schneider Stepdown Ring for 77mm Filter To 72mm (65-041214)

Which brand depends on how much you can afford to spend. B+W, Lee, and Singh-Ray are recommended brands.
B+W 65-073102 77mm Neutral Density 0.9-8x Filter #103

If more than $75 per filter is out of your budget, you might consider low-quality stuff - Tiffen 67mm Digital Neutral Denisty Filter Kit

Note: Schneider and B+W are the same company.

sactown024 · Oct 15, 2012

thank you very much!

tirediron · Oct 15, 2012

You can also look at Cokin products. These are the rectangular gel-style filters, and have the benefit of not vignetting at shorter focal-lengths (if you use a large enough size). They will however impart a slight magenta cast when shooting into/near the sun, but this can be controlled by shading the lens (I keep an 8x10 piece of matte-black craft foam - $1.00 @ Wal-mart - in my bag for this purpose).

ghache · Oct 15, 2012

i use the hoya pro 1d. great filters.

TCampbell · Oct 15, 2012

Each full "stop" on ND cuts the light in half and thus allows you to double the amount of time that the shutter is open.

If you were to only buy a single ND filter, I'd suggest a 3-stop filter. This because you should ALSO own a circular polarizer (not for waterfalls per se... but for lots of photography) and an circular polarizer can cut as much as 2 stops of light. That means you could stack a 3 stop ND (0.9) with a circular polarizer and you'd be blocking 5 stops.

Suppose your waterfall is in "sunny 16" lighting (a worse-case daylight scenario). You're at 1/100th (or 1/125th) at f/16 and ISO 100. Without having to touch the ISO or f-stop, 5 stops of ND filtering will take your show down to 1/60 -> 1/30 -> 1/15 -> 1/8 -> 1/4 second. That's enough to blur the waterfall. More time you add the smoother it'll be (and your camera might also be able to do ISO 50 and your lens might be able to go to f/22.)

Note that if you are using a wide-angle lens AND stacking filters, then the lens might be able to see the rings of all those filters -- it'll show up as a black vignette in the corners. They do make "slim" filters but often a slim filter has no threads on the front side so they can't be stacked.

As tirediron says -- the Cokin holder (which lets you slide in the square/rectangular filters made by Lee, Singh-Ray, or Cokin rather than the round thread-on filters) wont show vignetting because the sides of the bracket are far enough away from the lens' angle of view to be seen.