How to use long exposures to create mystical black and white images

In Black & White, Equipment & Technique, Landscapes, ND Filters, Scenes & Scenarios by Cole ThompsonLeave a Comment

I have always been intrigued by monoliths, first by the statues on Easter Island, then by the monolith in the film 2001: A Space Odyssey and most recently by Stonehenge in England. In each case, seeing these monoliths prompts the question; Who built them and for what purpose? I’ve always loved visiting Bandon Beach in Oregon because of the natural monoliths strewn along the coastline. Randomly placed, it is as though the earth were God’s chessboard and the monoliths the pieces from an unfinished game. I’ve included several images of these Bandon Beach monoliths to illustrate my use of long exposures for my various monochrome print portfolios.

I have often created my monolith images using long exposures of 30 seconds, but recently I found myself experimenting with daytime exposures of up to 5 minutes. In each case, whether 30 seconds or up to 5 minutes, the Singh-Ray Vari-ND filter was essential to creating these images. If you’ve ever tried such exposures with a fixed ND filter, you know the challenges. First, to compose you have to remove the filter because the filters are so dark you cannot see through the viewfinder. Second, when removing and replacing these filters you can accidentally change the focus or the focal length of your lens. Often you’re not even aware of these lens movements until later, when it’s too late.

When I mount the Vari-ND filter on my lens, I dial it to the minimum (Min) setting. At this point the filter has already added about 2 f-stops of density which is just enough to darken the image in the viewfinder a bit, but I can still see clearly enough to compose and focus accurately. I then rotate the front ring to increase the density by as much as 6 additional f-stops. When I need even more density, I stack the Singh-Ray Mor-Slo 5-stop ND Filter in front of the the Vari-ND to achieve up to 13 stops of density. This allows me to use very long exposures, even in full daylight.

Here are some of the things I’ve learned about using very long exposures. First a tripod is a must and a remote shutter release is desirable. While it’s true that slight camera movements do not seriously affect the very long exposure, it’s best to eliminate vibrations as a “best practice” and because camera movement can ruin an image with a 5 second exposure or less. I shoot at ISO 50 at F22, put my camera into RAW/monochrome mode and set the exposure mode to manual.

The most frequent question I am asked is how I determine my exposure. I use the in-camera meter for exposures up to 30 seconds, and beyond that I find I must extrapolate because the digital SLR’s I use only meter up to 30 seconds. With my camera set to F22 and 30 seconds, I dial my Vari-ND’s density ring until my exposure is correct. To extrapolate for exposures longer than 30 seconds, I do the same thing but set the exposure to 2 f-stops below ideal and then quadruple the exposure in my head. If 30 seconds is what I’m metering for, then quadrupling brings me to a 120-second exposure.

But strange as it seems, if I expose at 120 seconds, the image will be very underexposed. So I’ll generally expose at 300 seconds for a good exposure. I’m not sure why the 120 seconds doesn’t produce the correct exposure, but it could be due to some kind of digital equivalent to ‘reciprocity failure,’ which is a phenomenon experienced when shooting extra long exposures with film. The reason for such reciprocity failure with film is that the longer the exposure, the less effective the film is in recording the light and so the exposure length needs to be increased. In the case of my digital camera, when the meter says I need a 120 second exposure I extrapolate that reading and give it 300 seconds. It works for me.

Something else that is very important when using the in-camera meter is that I must completely isolate stray light from coming into the viewfinder and affecting the meter reading. To do this I use a Hoodman eye-cup which allows me to seal the viewfinder with my eye. This is essential for a correct exposure.

Shooting long exposures at the beach creates a couple of additional challenges. Waves hitting the tripod legs will cause them to sink into the sand, ruining the exposure. I can either move out of the water line or build wide feet for my tripod that give it a larger footprint. The beach also has strong winds and a lens makes a great wind sail. I combat this by using a heavy tripod that allows me to hang a weight onto the center column to steady it. I also position myself between the wind and the camera and often turn my jacket up above my head and use it as a wind shield.

Lastly, let me repeat that camera movement is the primary enemy of long exposures. Even the slightest movements can ruin the image. Sometimes it’s just not easy to detect this movement by checking the camera’s display. For this reason, I check every image with a hooded loupe which enables me to see the image clearly even outdoors.

I have found extra-long exposures to be especially appealing to me, perhaps because they help convey nature as timeless. I’ve come to a point where the technique has become part of the message in my work. Choosing the length of the long exposure will control how that movement looks in both water and sky. Exposures from 2-30 seconds can give a completely different look in water while the longer exposures measured in minutes are usually needed to produce dramatic skies.

There is no better tool than the Vari-ND to produce these types of images. As I’ve said before in my other Singh-Ray posts, this filter not only makes it easier for me to create these images, in many cases I could not have produced them without the Vari-ND.

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