treadwl Loc: South Florida

If you have a polarizer, you already have a 1.5 or a 2 stop ND filter. I have my polarizer, a 6 stop and a 10 stop. That seems to be all I need. I do suggest that you get an apt for your phone that will calculate exposure times. Many of my exposures times run into several minutes. I suggest sticking to good filters like B&W or Breakthrough Technology (breakthrough has very thin filters----this is a plus as it prevents shadows inthe corners of your images---any they have a LIFETIME warranty on their filters.

Shoeless_Photographer Loc: Lexington

wds0410 Loc: Nunya

I'll second the Breakthrough Photography filters. They are superb. I own a 3 stop and 6 stop NDs. I've never stacked them or used in conjunction with a polarizer.

GENorkus Loc: Washington Twp, Michigan

I applaud your want to expand in photography. People who don't must live boring lives.

dsmeltz Loc: Philadelphia

It kind of depends on the conditions in which you are shooting and what you want to achieve. They make filters in different densities because they are used for purposes. It is not possible to tell you which to use without knowing what you want to achieve.

PlymouthWoodworker Loc: Plymouth, MA

As billnikon noted, be sure to block the viewfinder during long exposures. I learned the hard way! Inexpensive plastic shades are available and are camera-specific if your camera does not have a built-in shade.

via the lens Loc: Northern California, near Yosemite NP

I use a 10-stop ND most often, a Breakthrough brand filter. Can turn things purple if any light gets into the camera. On a non-mirrorless you must set everything up, focus and composition, then put the filter on and shoot and check. After checking the image you can reset as you want. On a mirrorless camera you can see with the filter on, a real plus for this type of shooting. I do have a 6-stop ND but don't use it much as I usually want a mirror-smooth look. You can use a phone app to determine shutter settings.

tcthome Loc: NJ

you da man for posting this.

scubadoc Loc: Sarasota, FL

You can use a wide aperture in bright ambient light to obtain a narrow DOF.

fetzler Loc: North West PA

The choice depends on the lighting. In bright sunlight I have found uses for up to 13 stops.

Dikdik Loc: Winnipeg, Canada

Thanks...

Dik

so1150

Some good advice has been offered, I would submit another option probably worth your time to consider (cost and usefulness) would be a variable neutral density screw-in filter. I have personally used it with great success, yet it too has its limits and faults, ie., the dreaded 'x' at the higher stop range and occasional color cast. The benefit, to me, is the ability to focus at the lowest stop then adjust to the desired shutter speed. It can be stacked with a CPL as well. Step-up and step-down rings are very inexpensive; I own a 77mm VND filter and have easily adapted to my larger and smaller thread size lenses. YouTube has some great information to help you decide if this system works for your particular needs. Again, not a perfect option but works for me! Good luck with your LE photography :)

The attached pic was taken of a VERY rapidly moving Merced River with a VND filter, and while it smoothed out the water, due to the water flow, couldn't capture a 'mirror' reflection.

(Download)

steveg48

Most people that do long exposures use at least 10 stops. I use both 10 and 16 stop filters. This is for exposures in the 2-5 minute range. The main use is to blur clouds.