How to take Extended Exposures

Extended exposures are useful for many different types of photographs. They allow you to properly expose a dark sky, add a silky movement to flowing water, capture car headlights and tail lights moving, or take multiple exposures of a subject within one exposure using a strobe light. Most extended exposure photos require the use of a tripod – otherwise the images will suffer from camera shake and lack your desired outcome.

If you know you want to take an extended exposure there are two common methods for achieving this.

1) place camera in Tv shutter priority mode; set your shutter at the shutter speed you desire, or at longer shutter speeds ranging from 1/8th of a second to 30 seconds or longer via the use of a shutter release cable or remote timer.

2) place camera in manual mode, set your shutter speed at longer speeds and your aperture to a narrow number so less light is let in. If the photo is taken at night, wider apertures will allow for more light to be let in and shorter exposure times will be required. At night, the longer the exposure, the more noise you will have in your photo especially in the darker areas that are not exposed with greater shutter speeds.

As you can see with these photos, by extending your exposure time with a longer shutter, you can achieve movement and light trails, and properly expose sunsets and evening skies. Due to the extended shutter length, these shots all used a tripod, and a standard lens. The camera was set to ISO 100 – the lowest sensitivity, the lens aperture was narrowed to F/8-F/11, and the exposure was varied between 3 and 5 seconds.

What if we were taking these photos during the middle of the day and wanted to achieve the same effect? We could narrow aperture, and increase shutter speeds, but it is likely our shutter speed would never be long enough to capture movement during the day. When we narrow aperture too much, we introduce diffraction and a softening of the image. We can can reduce the shutter speed but you would lose that silky movement look, so instead you can wait for dusk or night, less light will permit longer exposures without over exposure. The darker the ambient light, the less risk of over exposure.

The second way to take extended exposures is by using neutral density and circular polarizer filters to add additional aperture stops to your lens. By adding one or two neutral density filters with 3 stops, you can add an additional 6 stops of light to your sensor, thereby allowing you to take the photo with a longer shutter speed while also keeping too much light from over exposing areas of your photo.

The following image represents a properly exposed photo of a waterfall scene during the middle of the day. There is a substantial amount of available light, and so shutter speed is quick and captures water movement with sharp clarity.

By extending my shutter speed with a manual exposure, I know have more of the “water movement” effect I desire however the water is blown out and the rest of the image is highly over exposed. I could either add an neutral density filter, or wait for less light.

Here is an example of waiting until night time to take the same photo. As you can see, i was able to capture the falls movement, and didn’t suffer from the ambient sun light over blowing the photo. An inexpensive “remedy” when neutral density filters are not readily available for your use.

17mm, ISO 100, F8, 20 seconds

Here is an example of an extended exposure combined with hyperfocal distance focusing.

Additionally, I can add a neutral density filter such as the B+W #106 6 stop neutral density filter and get results such as these:

City exposures at night:
Here is a photo taken with the original digital rebel

This photo was taken right at sunset, the sun had already gone down and the sky appeared mostly black. Through a 20 second exposure i was able to capture headlights driving, added ambient sky color, and more colorful lights from the buildings. Again not a perfect photo, but a nice example of an extended exposure.