Tech & Work

How to create long exposure photos without a lens filter

You can produce amazing long exposure photography using the power of Photoshop--even if you don't own a lens filter.

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Image: iStock/scyther5

I really enjoy shooting long exposure photography when I'm out at night shooting cityscapes. As I previously wrote, long exposure photographs are created when the camera shutter is held open for a longer period of time. This allows more light to hit the camera sensor. Doing a long exposure at night makes for awesome cityscapes, as the buildings tend to illuminate more. Plus, you can capture cool motion blur from passing vehicles with their lights on.

There are times I'd like to capture motion blur during the day, but holding the shutter open too long will overexpose the image because of the excess light provided by the sun. This means I needed a lens filter to decrease the amount of light hitting the sensor. But what if I didn't have a lens filter? Well there's a way to capture long exposure images during the bright daylight. Just use software—Lightroom and Photoshop in particular.

SEE: Getting started with drone photography (TechRepublic PDF)

What will you need?

Other than your camera, you'll need a steady base, preferably, a tripod. This is because you will be taking a series of shots that will be used to build one creative image. Having a tripod keeps the shot alignment and focus consistent.

Next, you'll need a remote trigger option to click your camera's shutter. There are several wireless options compatible with most DSLRs and mirrorless cameras today. For my shoot, I used the Pulse bluetooth wireless trigger from Alpine Labs. Wired shutter remotes will work also; just find one that's compatible with your device. As a last resort, you can use your camera's built-in shutter countdown feature. This allows you to manually click the shutter button and it will count down a few seconds before actually capturing your shot. This allows the camera to settle to stillness after your button press, so the shot capture will be motionless and reduce blur. Use this option only as a last resort, if you can.

You'll also need Adobe Photoshop to do the heavy lifting involved in creating your image. If you don't have Photoshop, you can sign up for a free trial period to see if you like the app—but note that Adobe Creative Cloud offers Photoshop as well as Lightroom for $10 per month. A great value, in my opinion.

Lastly, you'll need a compelling composition. The key with long long exposure photography is to tastefully capture motion blur. Set up your shot to have roughly two-thirds static imagery with one-third movement in the frame. A good example would be a busy street as it winds between local buildings. In my example, I'll use a flowing river.

SEE: DSLR Photography Course Bundle (TechRepublic Academy)

Setting up your shot

After you frame up the shot, lock in a few settings on your camera. Test to make sure your exposure is great (shutter speed, f-stop). Lock in your lens's focus and turn off auto focus. Manually setting and locking in your white balance isn't critical, but it doesn't hurt. Essentially, you want to prevent your camera from changing settings while shooting your series of shots. You want consistency, so locking in focus, white balance, and so forth, will help with that.

Next, grab your remote shutter device and click the trigger. After you know your shot has been captured, wait at least five seconds before shooting another shot. You can wait longer if you'd like, but having a delay between each exposure is what really makes this technique come to life, as small changes in movement are captured over time. It's similar to how a time lapse sequence is captured. For me, best practice is capturing at least 10 consecutive photographs with a five-second delay. You can do more, but you will be at the mercy of your computer's hardware and Photoshop for processing more than 10 images.

See: Gallery: Must-have mobile photography gadgets and accessories (ZDNet)

Let Lightroom and Photoshop do the work

After you've captured your shots, load them onto your computer for a quick preview and processing. Pull your photos into Lightroom to preview and also do any batch editing. I typically look at the first image in my sequence and do typical photo edits where I adjust exposure, contrast, etc. Once I'm done with that, I sync those edit updates across all of the photos in the sequence by selecting all of the images and clicking the Sync Settings button inside the Library module.

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This will open a dialog box showing all the edit options you can synchronize. Choose accordingly and select Synchronize.

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You'll see the edits take place on the images within a few seconds. Once done, select all the images, right-click, select Edit In, then select to open the images up as layers in Photoshop.

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You'll see all your images in the Layer panel of Photoshop. With all layers selected, go to your Edit menu and select to auto align the layers with the Auto projection option when the dialog pops up. As a personal preference, I like to duplicate (Ctrl+J) the first or last layer and rename it as "sharp" or something that tells me it's my layer that won't get utilized in the next step. Just move it to the bottom or top of your layer panel after it's renamed.

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After isolating your "sharp" layer, select all other layers. Right-click and select to convert these layers to a Smart Object. By converting to a Smart Object, you'll not only group the images, but you'll also have flexibility to modify any filters, touch-ups, or other adjustments made to all the images within the Smart Object.

Now let's see the magic of Photoshop. Adjust the stack mode of your layers by navigating to Layer>Smart Objects>Stack Mode>Mean, with your Smart Object layer selected in the Layer panel. By running the Mean option, you're telling Photoshop to take an average of the photos in your stack as it looks at exposure, focus, cropping, and even objects that may be in one image but not another. This calculation will create a final image that looks like a shot captured with a slow shutter: a long exposure.

Here's the "before" image. It has color and clarity to my liking, but the water's ripples are frozen in place. You don't get a sense of movement from the river's flow with this original image.

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Image: Ant Pruitt

After the Mean calculation is completed, you'll see more motion blur in your image. Notice the smooth blur shown in the river now.

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Image: Ant Pruitt

I must note that after I ran the Mean calculation, I also applied a layer mask to the Smart Object layer. This allowed me to use that "sharp" layer I created early in the process. By adding a layer mask, I could brush in sharpness in areas I decided required more detail—areas such as the trees in the background or the stones in the foreground. You can do other edits to the color and brightness if you like. I tend to do my final look in Lightroom, so in this case, I click Save after I've brushed in the sharp areas, close Photoshop, and the Adobe Dynamic Link feature takes me right back to Lightroom, as it was running in the background. Now I see my newly stacked photo with the fake long exposure.

Conclusion

It's always fun trying to create unique images in photography. It's even more fun knowing that images can be created multiple ways. I hope this will help you create some long exposure images, even if you don't own a proper lens filter. Feel free to check out my video below as I take you on the trail and through my process. I share my random musings, how the photo walk happens, and explain the Lightroom and Photoshop process. For more photography-related tips, follow me on Instagram and subscribe to my YouTube channel. You can tag me on Twitter with your favorite photos, too. I enjoy seeing what you all share.

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Your take

Have you found additional ways to capture long exposure images without a lens filter? Share your tips with fellow TechRepublic members.

About Ant Pruitt

Ant Pruitt is an IT Support Professional with a passion for showing the non-geek how great technology can be. He writes for a variety of tech publications and hosts his own podcast. Ant is also an avid photographer and weight lifter.

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