When it comes to landscape photography, using a long shutter speed to create smooth blurs of water is a highly popular technique. Occasionally, though, you might not be able to do that, as you might have forgotten your ND filter or you are just out on a quick walk. If that is the case, you can still create the effect in Photoshop, and this great video tutorial will show you what you need to know.
Coming to you from Anthony Morganti, this awesome video tutorial will show you how to blur water using Photoshop. Of course, if you can get it right in camera using an ND filter, you should, as it will save you some work in post and it will likely look more realistic, but of course, there are always instances where you might forget your filter or you might just be out and about and catching a quick snapshot. It can also be useful if, like in this example, there are a lot of trees surrounding the water and it happens to be a windy day that precludes the use of a longer shutter speed. Of course, you can always take two separate shots and composite them, but with leaves, this can sometimes be a bit of tedious process, and you might prefer this method instead. Check out the video above for the full rundown from Morganti.
I've used this technique on a few occasions and it works great. It's awesome that we as photographers have it as an option and can work out great in a pinch. The downside is that it takes quite a long time to process, especially when shooting with 60 megapixel files.
When Sony used to have the Sony Play Memories app support in their cameras, on the Sony A7r2 for example, you could simply install an app called "smooth reflection" that did all of this for you all in camera (without an ND filter). It basically did the same thing Photoshop is doing by combining all images then running a mean filter, but the final output from the camera was instead a single RAW file with all of the motion blur incorporated into it. No idea why they got rid of those apps, it's a shame.
Definitely a good Photoshop technique to know though