Thinking of a ND Filter...

[PhotoPatzer]

Any suggestions?

Also... do you use it freehand or use a mount and why?

[OsmosisStudios]

I have a screw-in .9 (3stop) ND filter. Works great for shooting large apertures in bright sunlight or with powerful flashes.

Depending on the effect you want to get, there are several filters of different strengths. What are you going to be using it for?

[PhotoPatzer]

Originally Posted by OsmosisStudios

I have a screw-in .9 (3stop) ND filter. Works great for shooting large apertures in bright sunlight or with powerful flashes.

Depending on the effect you want to get, there are several filters of different strengths. What are you going to be using it for?

Os, you are just the guy I was hoping to have answer this question!

I was thinking of using it mainly for landscape and some reverse tiki torch backlight subwash techniques.

Okay... Only for some landscape stuff... maybe I should do some more research for their different uses, before I buy one... I'm just trying to get a general feeling for how most use them and for what reasons. If anyone has a link or a good place to learn about ND filters, I'd love to know.

Thanks, OS!

[OsmosisStudios]

There are 2 main types of filters: Screw in and slot in.

Screw-in are great for anything where you want to get the same effect over the entire frame. Standard ND filters fit into this category, as they block light over the entire frame. Great for reducing exposure values to the point where you need a longer shutterspeed to get that lovely silky water effect.

Slot-in filters are more geared for landscape use and are generally used with gradient filters that go from effect to clear, or something similar. These are used in landscapes because they allow one to place the ND part over the sky (to darken it) but not over the ground (to maintain that light there). That means you can get a great sky and a great foreground without clipping either one (be it highlights or shadows, respectively).

If you're planning on doing anything extensive, a set of slot-in graduated ND filters (or "reverse" graduated ND filters, for sunsets) are probably your best bet.

Of course, in most cases both screw-in and slot-in systems can be used at the same time, so you can have a general ND filter to block light (for the water effect) AND use a graduated filter to block the light from the sky (to get a more even exposure). That can lead to some great images.

Now, all that being said, ND filters are fairly simple devices, but they can be an absolute bear to work with, the slot-in graduated ones in particular. Depending on your terrain (and the effects you want), you may need several filters that do the exact same thing, only slightly differently (harsher/smoother gradients from 0-100% ND). So you may end up with a stack of ND 0.9 (3 stop) filters, but one being a full soft gradient from one end of the filter to the other, and one being a harsh straight line across the middle, and a whole host of ones in between.

Usefulness of the gradient filters is a personal thing, as well. I dont personally like using filters all that much, and the slot systems are simply too much work. I'm more than happy to simply bracket my exposure to get 2 (or more) shots and use a gradient mask in post processing to get the sky from one and the foreground from the other while maintaining the middle.

YMMV.

[m.c.adams]

I use the Cokin System and it works good for me. I use both solid and gradual NDs. The system works great for the gradual as you can slide them to the position you need them in.
Mark

[inkista]

I'm lazy (and cheap) and not so much of a landscape photographer, so I have two screw-in ND filters. A two-stop 49mm filter that I use on my old Olympus OM-mount 50mm f/1.2, so that I can still shoot wide open in the daytime (sunglasses for my camera), and a 10-stop 58mm filter that I can slap onto a lot of my lenses to get longer expsures.

With an extreme ND like the 10-stop, you have to use a tripod, because you're aiming for multi-second exposures:

Without filter:

Canon XT. Summicron-R 35, adapted. f/8-ish. iso 100, 1/50s. tripod.

With filter:

Canon XT. Summicron-R 35, adapted. f/8-ish. iso 100, 39s. tripod.

The only drawback to using the B+W 110 (10-stop) is that it does have some leakage around the infrared end of the spectrum, so you have to watch the white balancing as you get a reddish cast. I've heard the Hoya 9-stop has a bluish cast.

[bono]

ND filters are really interesting. I just got a B+W ND113 (10000x) from ebay. I will try but only with a tripod...