Neutral Density Filter

stormchaser

Can anyone tell me what size ND filter I need for my D3200 please, and which one would be best for waterfalls, sea etc.?
Thank you!

bruto

Assuming the 18-55mm kit lens, the size is 52 millimeter.

For motion blur, the more the merrier, but beyond a certain point, you cannot hand hold, you cannot view through the lens, and you cannot focus. So you must pre-compose, pre-focus, and use a tripod.

For hand holding and using the auto focus, a two stop filter works very easily with only a little motion blur, but enough to be worthwhile. A four stop filter is about at the limit of auto focus, and the view will be dark. I might be inclined to try a 3 stop (6x in the traditional filter terminology). When you're hand holding, even with VR on, you can't get much slower than 1/4 second anyway, so a very dark filter is less important.

Variable density filters are a nice option, though the best are pretty expensive. You can get relative bargain ones from B&H and others. You can get something under 30 bucks, with a range from about 2 to 8 stops. This allows you to compose and focus, and then darken at will depending on what you need and whether you have a tripod.

You can also stack filters, but when you do, any faults and flare that they cause will be multiplied, and a deep stack will vignette. It still works, though, and allows some variation. Experimenting with mine, I find that two will work fine on the 18-55mm lens, and three will cause corner darkening (vignetting) when the lens is at its widest, disappearing at around 24mm.

When shopping for these filters, be aware that there are several different ways of measuring them; stops, filter factors, and other criteria. Make sure of which criteria you're using.

stormchaser

Thank you again for your help!
Karen.