This image was created around 5:30 PM on the beach in Maui, and has a shutter speed of 30 seconds. This provides time for the ebb and flow of the ocean to surge in and out of the rocks and creates the frothy milky look.
This is a great tool and using it can become part of any workshop, or if you want an entire workshop. A good filter is not cheap. And if you buy a cheap filter you get what you pay for. Less expensive filters are not constructed as well nor do they last as long. And, they are easier to scratch. A rotating ND filter is not suggested. Get one that screws on or slides in a mount .
I wanted the Lee Big Stopper ($150) but each time I want online they were back ordered. Since all my U/V filters are B&W I went with their coated 10 stop ND filter, it cost $200 at the camera store in town. It is the screw in type at 77 mm in size.
I use the filter to shoot scenic landscapes and believe that anyone passionate about photography will like using it too. You will enjoy the creativity it provides. There is a learning curve to using this filter so don’t expect magic right away. The good news is fun, fast, and easy to learn, making the process a real pleasant experience.