@ John, I do them as well, but I pick and choose what scenes and the effect I'm after, artistically. I'm pretty picky about the results.
I've done so to add motion blur to clouds (they need to moving towards you, or away from you to look picturesque) and of course for an ethereal
silky flow to waterfalls and streams. I avoid 10 stop ND filters for that since I dont shoot forested scenes in daylight.
I don't have any such filters but long exposures are popular where I live for rocket launches. Especially at night. If you use a wide angle lens you can trace a nice arc across the night sky. A filter can be of help to avoid overexposure.
I love it too and I used to do the same using the square filters kit. Then I decided to use a camera that has the long exposure as its feature and that is much lighter to carry in my backpack: Pinhole camera. And Pinhole photography became my main photography work for at least 3 or 4 years. I shot even portraits with it.
Do you know why I love it? Because while I wait the exposure to be done I can contemplate what I am photographing and it feels good.
It is part of my philosophy to work against the rushy tendency we live in today's society and go back to the approach humanity used to have before the "work salvation" (work doctrine) of our industrial and service society; work and production not as a mean for acumulation and consumption but a mean for contemplation.
We rush so much today in order to accumulated and consume (including experiences) but with the lack of contemplation in our experiences they become empty. So we feel empty, bored and waisting time if not over producing and consuming.
So my goal is to create art that reflects my attempt to go back to experiences that reflects it. Although I am guilty of going against my own philosophy as attempt to obtein the marketing and sales results, specially when I am really broken.
The only time I've used the very long exposure technique was for some city scenes a long time ago. An exposure of about one minute makes a lot of moving people "disappear" from the scene. That only works, of course, for people who are actually moving and not seated on a bench or leaning against a wall. YMMV
I use a ND filter, but usually only for cloud movement. I do not use it for moving water, because I almost always shoot in overcast conditions with a polarizing filter and get all the blur I want. I usually prefer some definition in my moving water as opposed to the pure white silky look, but that is just me. John, I like your cloud movement shots.
I love it too. It's my favorite form of photography. I need to invest in a 10 stop filter for some of my new lenses. I only have one that fits my older lenses. No one can talk be out of it because it's my love too. My favorite use of it is with waterfalls, oceans and night exposures. I also like it with clouds in some scenes. Sometimes water looks better without a long exposure but I always take the photo both ways and then I can decide which one I like best when I can see it larger. I don't think I've ever really liked a waterfall image that wasn't a long exposure. But too long of an exposure can also ruin the shot.
I love long exposure photography, it's great. I use it from time to time. I always have a 10 stop ND filter on me. I generally have a specific purpose if I'm setting up a long exposure.
For instance, for city night shots I go back and forth between doing long exposures and using a fast lens depending on what I'm going for. Even handheld, my D750 + a 1.4 lens can make for beautiful night time city shots. I tend to like nightlife photos so I like freezing the people in the shot which requires a relatively fast shutter speed. But sometimes I like car trails and turning the points of lights into stars so I'll bust out the tripod. I also LOVE astrophotography which obviously requires long exposures (sometimes a half hour or more for star trails).
It's all good.
Jennifer what I did was to buy a 10 stop ND filter that fits my largest lens then it's much cheaper just to buy a bunch of step-up rings so you can fit it on all of your other lenses.
One thing I don't care for is long exposures of the sea. People please stop that. There is nothing attractive about blurry images. It makes me rub my eyes and clean my glasses. Maybe a slight blur on some of the movement is ok, but when the subject is blurry, that is not good photography.
You can keep the creamy waterfalls too. It looks so fake.
I would like to do some night shots in urban areas where the traffic blurs into lines of red and white and the people disappear. That looks pretty cool.
I've done a fair bit of LE work over the years on both film and digital. Film was more of a challenge due to reciprocity failure, so digital certainly simplified the process and that's why I've tended to do much more on the digital side. I find it works well for some scenes and not so well for others and the simplest approach is to ask yourself what you think adding LE brings to the scene rather than just doing it for the sake of. For instance, if a scene is quite detailed with a busy sky/water/etc. within the scene causing too much distraction I will generally use LE to focus more attention on the main subject. Castles work well for this, especially in b&w, as the viewers attention can be drawn to the castle by softening any clouds/surrounding water with LE. It also tends to add more drama. My two cents.
I do long exposures quite a bit, using the Benro 100mm square filter system with a 10-stop and a 4-stop ND (plus grads when needed). I don't do it a ton, but when the scene calls for it, I'm all over it.