Lens filters are useful for achieving a variety of photographic effects in camera, such as long exposures of moving subjects. But did you know you can achieve the same great results with Photoshop CC?
Neutral density filters are great for darkening the whole of your frame when shooting, either to allow for wider apertures in bright situations or to extend shutter speeds when wanting to shoot long exposures of moving subjects. For example, a 6-stop ND filter might make it possible to shoot a 30-second exposure even while shooting during the day.
But what happens when you stumble across the perfect scene but don't have your filter with you? Or perhaps you just wish you could put that same long exposure effect on an image you've already taken. Luckily for you, it's relatively simple to do this in Photoshop CC using basic editing techniques you probably already know. So, follow along below to discover how to do it yourself.
1. Select Your Scene
I took this shot of a sunset in the rolling Cotswold hills in the UK a while back. At the time, I didn't have my ND filter with me. I saw the clouds were doing something special, though, and took a snap all the same. Looking at it now, I realize it would benefit from some long exposure movement in the clouds. So I started by first importing the photo to Photoshop CC. Once open, I went to the Quick Selection tool (W) and used the click and drag method to select the entire sky.
Be careful when using the keyboard shortcut for this tool, as there are three different options nowadays: Quick Selection, Magic Wand, and Object Selection. I used the Quick Selection tool because Magic Wand was a little too selective given the tones I have in the clouds, and there is no real object to speak of to use Object Selection. But, you may find one of the other tools works better for your photo.
2. Zoom in and Refine
Though the sky selection process was simple and it seemed to do a good job, I was aware that there were distant mountain ranges and hills that were much more subtle due to the haze in the sky. I zoomed in (press Z to select the Zoom tool, then click and drag to the right) and noticed that the Quick Selection tool did, in fact, miss these areas. So, I held Alt and deselected the mountains so that only the sky had a marching ants selection around it. Alternatively, you can just click the Remove Selection button in the toolbar at the top of the window. Adjust your selection until only the sky is highlighted.
3. Duplicate the Layer
Arguably, you could do this step first, but I like to include it now after I've already made my selection, because sometimes, I prefer to just duplicate the selection first. For demonstration purposes, though, it's easier to show you how to mask effectively in the coming steps if we duplicate this layer now (it also makes it future-proof should you notice a mask wasn't exact in the first place). To duplicate the layer, right-click on it in the layers palette and click Duplicate Layer.
4. Add a Mask
Now that you have your duplicated layer (appearing above the original imported "background" layer), click the Add Layer Mask button at the bottom of the layers palette to apply the mask. Zoom out to fit the window by pressing Ctrl + 0 and then hold down Alt and left-click on the eye icon to the left of the layer; this will make only that layer visible. Take some time to look over the mask and check for any inaccuracies in the selection process. If you notice anything drastic, hit Ctrl + Z a few times to undo until you get back to the marching ants selection and use the above steps to refine it.
5. Come on and Blur it Up
It's now time to add the blur effect. With the image thumbnail selected on the newly masked layer, head to Filter>Blur>Radial Blur. I prefer to use the Zoom blur method as this is most realistic when matching up with real-life long exposure effects (clouds generally blow in just one direction, not circling as they move as you might get using the Spin method).
I also like using the best quality option because, well, why wouldn't you want the best if you have time for it to process? I've used a heavy blur amount here, set to +83, but you may want to experiment with this depending on how intense you want the effect to be. The last step is to pay attention to that little white example box on the right; from here, you can click and drag the middle focal point to wherever you like. I placed it just above a beautiful hill with a small copse on top. That's because I wanted the blurred lines to sort of point towards this area as I think it's the most attractive part of the frame. This is another benefit of Photoshopping the effect rather than relying on filters and natural movement: you get to choose where the movement occurs and in which direction.
6. Time to Review
If you've made a good selection to start with and the blur filter is perfected, you should be pretty much done at this point. Occasionally, though, you might notice that the gorgeous radial filter you added may have unintentionally lifted some of the background colors or shapes into the blurred section. I purposely did this to show you how to get rid of it (do you believe me?), as it's relatively simple. Let's zoom in and take a closer look at the problem.
7. Refine That Mask
Now zoomed in, I can see that the edge of the horizon was just being dragged into view in the affected layer because I had set the intensity amount of the radial filter so high. It's a simple job to fix, though. Just click on the layer mask and use your brush tool (B) to paint away the ghosting effect. Don't forget: white reveals, black conceals. If you want to see where you're painting while doing this, hit the \ key on your keyboard to reveal the red layer mask.
Now that I've refined that layer mask. the mix between blurred and original layer is now indistinguishable. The effect, though not natural, is quite realistic, and the benefit is that I can do this with as many different photos as I like. It's also customizable, so I can increase or decrease the intensity in any photo I choose. Also, the direction and placement of that radial focal point is interchangeable, so you can create perfect long exposures every time, no matter the composition or subject placement.