The Vari-ND is a handy filter if you want to take pictures of waterfalls with the water all blurred. Normally, this is hard to do in daylight since it is not possible to get a correct exposure with the slow shutter speed needed to blur the falling water (5-15sec). The Vari-ND adds 2-8 stops of ND filtering that enables much slower shutter speeds. If this still isn’t enough, Sing Ray makes a companion filter - the MOR-Slo, which adds another 5 stops. Taking these kind of pictures can be tricky but rewarding. I have tried it a few times with mixed success. The instructions below come from Jason O’dell’s combined with my own experiences.
- You will need a sturdy tripod and remote shutter release. You will be using the Mup function on the camera to get maximum sharpness.
- Set camera to the lowest ISO (200 on the D700)
- Set Mup
- Set WB to Daylight (to avoid long exposure color shifts with Auto WB)
- Adjust the Vari-ND to minimum in order to set the focus through the viewfinder (be sure to set the camera such that the focus is set with the “AF-ON” button only, not when the shutter is depressed half way)
- Set camera exposure to Manual and enter the desired shutter speed and aperture (ex 10sec, f/16)
- Close the viewfinder
- Adjust the Vari-ND ring until the camera shows correct exposure (if it is too bright, you may need to shorten the shutter time or close down the aperture more, or use the MOR-Slo).
- Set Long Exp NR ON
- Take a series of pictures, bracketing the exposure. Zoom in to check focus
Note. An alternative to focussing is to use “live view”. This is probably easier than the above method because it can be done at the set shutter speed and exposure, with the Vari-ND already adjusted. However, you cannot use M-up and Lv at the same time. So, once focus is set, you need to come out of Lv and set Mup, then take the picture