Long exposure in camera photographs have been around since the first photograph was taken in the 1820's, as originally it would take many seconds/minutes to complete an exposure. So subjects within the composition would have to be deadly still and you don't see many smiles in early photographs for this reason, as who could hold a smile for that long! I've always been intrigued by long exposures in the modern age, as it allows you to see the world differently and I always appreciated the variety of aesthetics it could provide. The likes of Michael Levin, Michael Kenna and Jonathan Chritchley are all artists that have adopted long exposure photography in their seascape compositions. With the availability of todays technology, it's much easier to produce eye-catching professional results. In this blog I wanted to run through my own workflow when taking a long exposure photograph in the field. Please remember, everybody has their own preferences when it comes to photography, but feel free to take away what you like from this article.
Some of the most important fundamentals of long exposure are - a sturdy tripod, a good quality ball head, DSLR and a selection of Neutral Density Filters . I use a carbon fibre Manfrotto 055CXPRO4 with the MHXPRO-BHQ6 ball head which gives me suburb stability and flexibility that I need when composing an image and the 100mm Lee Filter system. The above image was taken using this tripod / filters and features the Dovercourt Lighthouse at sunrise. As the shot was taken on soft sand, I had to be careful that the tripod legs didn't sink into the ground during the exposure and one way to combat this is to place CD's under the legs to distribute the weight. Once you have positioned the tripod and framed the composition, it's good practice to place the filter holder onto the lens prior to taking a test shot, this way, by fitting the holder now will reduce any interference with your focal length or focus ring later. It's also a good time to plug in your shutter release cable. Now input the correct settings into your camera using manual mode before you place any filters into the filter holder system. In the case of the above image and due to the low light as the sun was yet to rise, I used F11, 2sec, ISO 50 at 70mm (Canon 24-70mm lens). Always focus in manual mode looking through your LCD screen when taking the test shot to ensure maximum sharpness, but to also avoid an issues when you place the filters over the lens. If you shoot in Auto-Focus mode when there are ND filters in-front of your lens, then your camera will struggle to find a subject to focus on due to the density of the dark glass.
OK, so you've taken a test shot and you've checked the image for sharpness and depth of field on the back of your camera's LCD. Now select the correct ND filter, in the case of the above photograph I used a 6 stop ND Lee Filter. Memorise your camera settings and change the camera into Bulb mode. So in the case of a long exposure, the only setting that should change is your shutter speed - so in bulb mode select your memorised F-stop and ISO, being careful not to touch the lens so that the focal length or focus is adjusted. Then slide the ND filter into the holder and make sure there are no gaps where light can leak into the camera. You also need to make sure that the eye-piece on you camera is covered as light can sometimes refract into camera and onto your sensor.
To work out the shutter speed, your chosen brand (in my case Lee Filters) should provide you with an exposure card or app that can determine the correct exposure time. By inputting the shutter speed (as per the test shot) and the ND filter being used, it will spit out the correct shutter speed required for the ND filter you have chosen to use. So on the Lee Filter System App, I chose the 6 stops tab and 2secs and it gave me a shutter speed of 2 minutes. Knowing that the settings have already been determined, all you have to do now is click and lock the cable release in place for the required time. The image will then complete and appear on your LCD. Always check the sharpness of your long exposure and the histogram to make sure the correct exposure time has been selected.
Top Tip(s): When taking the test shot, always weight the histogram to the right so you are almost clipping the highlights. Also consider using a soft graduated filter if the sky is particularly bright.
