One of my very favorite things to do when shooting nature and landscapes is to experiment with long exposures Anytime I have the opportunity to get a creative exposure of clouds or water, I try to take it.
Here are some tips to help you find success when experimenting with long exposures:
1) A tripod is your best friend. I know, I know, they are cumbersome and a pain to carry but are necessary so that you can keep your frame stable throughout the long exposure. Make sure your tripod is steady and secure.
2) Invest in good Neutral Density Filters. I recommend a 6 stop and/or 10 stop ND filter. In brighter light and to get 30 second or longer exposures, you will often need a 10 stop filter. In lower light and/or an exposure of just a couple seconds, a 6 stop filter may be sufficient. For even longer exposures in daylight you can use a 15 stop filter as well. There are many companies that make Neutral Density Filters in various price ranges.
3) Compose your frame and focus for the desired depth of field BEFORE putting the filter in front of the lens. Once you put a 10 stop filter on, you can't see through to focus and compose.
4) Set the new exposure BEFORE putting the filter on the lens. Find your proper exposure without the filter on. Then you can use a Long Exposure Calculator App to find the new shutter speed after you put on the filter. Usually you will need to max out your ISO and aperture unless you are shooting in really low light. For example, say I set my ISO to 100 and aperture to f/22 and my base shutter speed is 1/80. If I enter into the app a 1/80 shutter speed and tell it I am using a 10 stop filter, the app will then tell me that a 13 second shutter speed will give me the same exposure with the filter on. So then I will change my shutter speed to 13 seconds before I put on the filter. The less I touch my camera after putting on the filter, the better.
5) Use a Shutter release remote. These are critical if you are using a shutter speed slower than 30 seconds as you must then turn to bulb mode. But even out of bulb mode, using a shutter release is one more way to eliminate the chances of bumping your frame and increasing sharp focus. If you don’t have a shutter release you can also use your camera’s timer delay.
6) Cover your eyepiece viewfinder to prevent light from coming into the frame as this creates undesirable light leaks. My Nikon D810 and D850 have a little door that covers the eyepiece. But otherwise, I would cover it with a black/dark cloth or anything else that will keep the light out.
7) Check your histogram. Sometimes finding the right exposure with the filter can be a bit of trial and error. Don’t rely on the app or the LCD screen. Make sure the histogram is toward the right without climbing the right wall. If you need to bump exposure, lower that shutter speed, OR if your shutter speed is where you want it for creative effect, raise your ISO or open up your aperture.
8) Consider the creative effect and mood of the image you want to create! When choosing your shutter speed length, think about your creative vision. For really streaked clouds, you may need a 60 second exposure or even a few minutes. If clouds are moving fast, 15-30 seconds may create the look you desire. With water, you may want to create a really smooth effect with 20-60 seconds or perhaps you want to leave more texture in the water with a 1 second exposure or a fraction of a second.
9) Lastly, look at the other areas of your frame. Do you have unwanted blur in other areas of your frame…such as trees, grasses or other foliage? If so, capture the exact composed frame with a faster speed so you can composite the two images later in post processing.