Following on from last week’s post, our next exercise in exposure was to use long exposures at the end of the day to record some motion in the sea and clouds. This saw us ending our day at about 9pm with a walk home around the base of the Mount in the dark. Using a 9 stop ND filter can give you nice long exposures earlier in the day and I used it for the first two and final images here but the third one was taken well after sunset so by using the base ISO of 64 on the D810 I didn’t need the additional light reduction of a ND filter. The way the water renders depends on the amount of wave action and length of exposure. I have included the final image with a 30s exposure to show the misty effect that can be achieved. In some cases this can be effective but I usually like to keep more texture and feeling of motion in the water but this has to be juggled against what motion you want to record in the clouds.

When using an ND filter it is sometimes difficult to easily work out exposure values from the metered reading without the filter and I find the NDTimer app on my iPhone very helpful. You simply enter your metered shutter speed for the aperture/ISO you have chosen, enter the filter density (ND value or stops) and it gives you the new exposure time. For more information on Neutral Density filters see my December 2013 blog post. Variable ND filters sound convenient but I am not a big fan of them as they can cause uneven exposure across the frame. I have 3 stop and 9 stop filters and find that I generally only use the 9 stop as I am almost always using wide angle lenses with a generous depth of field that gives some latitude in aperture choice and combined with the wide range of usable ISO values on modern cameras I have plenty of flexibility in exposure values. Obviously with these long exposures a tripod is essential and I use a carbon fibre Manfrotto 055MF3 with a Really Right Stuff BHB55 ball head which is a reasonable compromise between weight and stability when needing to carry it any distance.