Neutral Density Filters

[rmcheek]

I'm looking at Neutral Density filters and I'm new to photography, but I dont know how dark to go. I want to do long exposures both day and night. Whats the difference between ND filters? Which ones should i buy?

[ravncat]

Neutral density filters are usually marked with stop values (but not always)

For example, you could by a 2 stop or a 4 stop neutral density filter - that tells you how much you have to compensate the exposure for. So if you needed to make an exposure that would normally be 1/15th of a second, a 1 second exposure, you would need a 2 stop neutral density filter.

The darker the filter - the longer you can make a given exposure.


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There are also graduated neutral density filters - these are a bit different, and only make part of the scene darker - they are used for balancing the sky with a landscape most often. (will take a bright sky and make it darker so it is easier to expose for the whole image.

as for which you should buy - depends on what you want to do, sometimes you can stack ND filters as well. so a 1 and a 2 stop filter could give you 3 stops if you stack them.You can even buy a 10 stop filter if you need multiple hour long exposures.

[IainM]

Well, it's somewhat obvious to say, but it depends on how bright a place is and how slow you want to make the shutter speed as to what ND filter is good.

But, that being said, in somewhat darker conditions you often dont really need an nd filter, just a small aperture will do it.

In brighter conditions there are two common and useful filters (for me anyway) that I often use - an ND8 and an ND400

The 8 darkens things enough to allow slower shutter speeds of say 1 1/10th of a second in relatively bright light (which is slow enough to give running water enough of a blur to give it movement without it coming out like silky cloud) and the ND400 really darkens things down to allow for 30 second or more exposures in bright daylight. Which is great for removing people from the scene or for really interesting water/cloud effects.

my 2c.

[OsmosisStudios]

I have 2 ND filters: ND8 (3 stop) and ND1000 (10 stops).

I use the 3-stop fairly often to use larger apertures outdoors during the day (particularly with film), but the 10-stop is a special use filter for sure. It gives me 30s exposures at f/11, 100ISO in the middle of a bright sunny day. So it's sweet.

[Preeb]

I almost opened a new thread asking the same question.... gotta love the search button.

I was looking to find out what good choice for a first ND filter would be, and now I'm thinking that the ND-8 will be enough to get me a start. Thanks for the help.

[jdepould]

You can also get vari-ND filters that work sort of like circular polarizers. They have two elements, and you twist to adjust the darkness.

[gazsus]

Originally Posted by OsmosisStudios

I have 2 ND filters: ND8 (3 stop) and ND1000 (10 stops).

I use the 3-stop fairly often to use larger apertures outdoors during the day (particularly with film), but the 10-stop is a special use filter for sure. It gives me 30s exposures at f/11, 100ISO in the middle of a bright sunny day. So it's sweet.

I guess different makes have different codes, mine is an ND 3.0 which is a 10-stop, from B&W. And yes it's pretty special

[Krusty79]

If you want a ND filter to do long exposures, it sounds like you do not want the graduated type, which is used to decrease the brightness of the sky relative to the ground. If you do not have a circular polarizer yet, you could use that to reduce the light by 1-3 stops. If you wants those really long shutter speeds, you'll need a ND filter.

Here is another related thread - Screw-on filters or rectangular filter system?

[ravncat]

A lot of people will get a set- usually a 1, 2 and 4 stop ND filter set - as that lets you combine them to get 1-7 stops... but I must confess- I only have an nd 4 and a grad nd 2 - I've found I can get away with alot that way... my polarizer filter factor can add to that if needed...

I don't use them nearly as much as I should - I must be getting lazy

[kirbinster]

I have a 10 stop that I love. Its great for long exposures of moving water on a bright day. It is also wonderful for taking long shots of tourist attractions and making the people vanish.