Recent work: Smoke on the Water

I was fortunate to capture this long exposure rocky shoreline image recently on the northern California coast.  The "fog" effect is simple to understand but takes some planning and composition attention.  There was no fog, rather many waves came in and out during the 30 seconds that my shutter was open.  They created a motion blur resembling a low layer of fog.  From a technical standpoint, getting an exposure long enough for this requires a small aperture and low ISO.  Also very low light unless you have a ND "neutral density" filter.  In this case the sun had just set and it was plenty bright enough to rock hope on slippery rocks and wade through cold November Pacific water to reach a suitable location.  In the dark, this would have been much more tricky and dangerous.

Luckily I had a ND filter, which is simply a dark filter that cuts down the amount of light entering the lens. 
It doesn't change the color or polarize, it simply reduces light specifically for lengthening exposure times.  The particular one I used here is a 9 stop ND filter, which means it cuts down the light by 9 times.  At f/22 and ISO 50, 30 seconds gave a correct exposure.  Obviously a tripod is necessary to steady the camera.  I also have a 3 stop ND filter which would have also gave motion blur to the waves, but my exposure time would have been 5 times shorter (9-3=5) giving me a 6 second exposure. Given the wave frequency, the look might have been interesting but not a total blur which is what I was after.

Regarding composition.  This is a common type of shot for a shoreline landscape.  I find that soft diffused light is best, either before dawn or after dusk.  Or on a cloudy day.  The color and mood should be cool and soft to bring out the classic ethereal look.  I like a dramatic wide angle perspective, in this case 24mm.  Also your viewpoint needs to be low to see depth in the "fog".  I was just above water level with my tripod extended about 5'.  Obviously there is risk to your gear if you get too close, at the very least your lens/filter will get splashed with water.  Also there are certainly safety concerns; rogue waves, rip tides, sharp rock etc.  Be very careful, the slippery rock really was treacherous that day.  And when I thought I was at a plenty safe distance, a larger wave would surprise me and narrowly miss my camera.

I've been wanting an image like this for a long time and am happy with the results.  Though my 9 stop ND filter has been a fantastic investment and will be staying in my gear bag full time.