This is the fourth in a multi-part series on Exposure. The first post introduced the three corners of the Exposure Triangle – ISO, shutter and aperture. Since then we’ve covered the ISO corner and began a discussion of slow shutter speeds.

Today we will continue with that topic. We will cover fast shutter speeds next week and follow with a post (or two?) on aperture settings (small & large maybe?).

Recall that choosing the correct ISO is the first step to ensure the correct exposure is achieved while allowing shutter speeds and/or apertures that “work” for the scene.

Last week we discussed a landscape photographer. He/she must work at low ISO to ensure completely noise-free photos. The low ISO was one reason they work with slow shutter speeds (long exposures).

Today we will look at some creative uses of long exposures.

The photos above were taken in near pitch black conditions at Joshua Tree National Park, a local site Rebecca and I visit every year. We will be camping there in February.

Turning night into day requires very long exposures – both used 30-second exposures. There are photographers that excel in this with better examples of nighttime photos including vistas of the Milky Way or star trails highlighting the  being common.

Slow shutter speeds can also lead to subject motion blur as shown in the photos below. The left panel is Times Square in NYC. The slow shutter (0.3 sec) was used to properly expose the image at a low ISO.

The motion blur of the people walking isn’t overly obvious because they are walking straight at the camera. The vehicle blur is more pronounced — they are moving faster.

The indoor waterfall at a Las Vegas hotel was photographed with an even longer exposure to allow the water to stream across the frame.

The photos below use subject blur to impart a feeling of motion. The bicyclists were whisking by our campsite at Big Basin Redwoods Park in central CA. Check out this post or this one for more examples of and techniques using motion blur.

The Ferris wheel at the Irvine Spectrum was lit and running with holiday lighting to boot.

Sometimes it’s just fun to play and see what you get. That was the case with the colorful streak photo below. The camera was panned across the scene during the 2 sec. exposure.

For the life of me I can’t recall where this photo was taken. I know from the metadata that we were on a trip to San Diego. Maybe that lack of detail adds to the appeal – I’m not sure — but I like the mystery & implied motion.

The second panel is a lens zoom technique I was practicing a few years ago using Rebecca’s Christmas decorations. During the 1 sec exposure the lens is zoomed in or out (I can’t recall) to create this interesting effect.

I’ll close this post with a relatively advanced technique, “Dragging the shutter”, that you can try if you’re willing to play around in manual mode. This will work with many point & shoot or other compact cameras.

This is a flash technique that captures background detail by using a long shutter (dragging the shutter).

Dragging the shutter in this case meant using a 1/4 sec shutter speed. Now we know all about the pitfalls of camera shake but here’s a situation where it doesn’t apply.

How were we able to ward off the evil villain — camera shake? Korina & Luis are predominantly exposed by light from the flash. The burst of light from the flash is over in 1/1,000 sec.

Bottom Line: there is no need to worry about camera shake when your portrait subjects are exposed by flash. Bottom Line2: It’s always best to use proper techniques to minimize the amount of camera shake.

The background sees very little light from the flash (see this post re: flash vs. distance). If this had been shot at the standard flash exposure of 1/60 sec they would be sitting in a “dark cave” void of background details.

By using a slow shutter the background is reasonably well exposed. It may be a bit blurred from camera shake but frankly, who cares.

Your camera may have a picture mode that attempts to “drag the shutter” — check your manual for details. The best way to achieve this look is to take full control of your camera settings by shooting in manual mode.

Try it — you’ll love it.

Another post on exposure — four down, three to go?!? I hope you’re finding this useful. Try to check back to get the whole story. I’ll probably put up a summary/highlight post when we’re done covering the details.

As always, feel free to comment or show off some of your own compositions that illustrate this tip. In the meantime, stay tuned because next week we review fast shutter speeds for stopping motion. Better yet — be updated automatically by “friending” our Facebook site.

PS - This is one of dozens of photo tips in our continuing Tuesday Photo Tips series of posts. There  are other resource articles on our site you may enjoy covering basic and more advanced photography topics. There are also tips covering topics such as preparing for family or infant/child portrait sessions. If you would like a topic covered just jot it down in a comment or send us a note.