I was recently down in downtown Grand Rapids one night doing some nighttime photography. I was using a long shutter speed to be able to get the photos of the night lights of the cityscape. I was using a tripod for all the shots since I was doing long shutter speeds. Most people would think that this is enough to be able to get a good shot. Well the challenge is that when you push the shutter button, no matter how careful you are, you will most likely move the camera some. If your shutter speed is like 1 to 3 seconds that movement could be a significant portion of the photo. And then you will end up with a blurry photo when it should be picture perfect (pun intended). You will end up with something like this (click on the photos for a close up).
The photo is a little blurry. Really small you cannot really tell (like on the camera LCD), but when you look at it larger it is really obvious. So what you need to do instead is to get the shutter to trigger without your hand on the camera. You can use a remote trigger. These can be wireless or wired. But that way you can trip the shutter without any possible chance of jarring the camera and end up with a clear photo.
Another example of a blurry photo from having the hand on the camera that I took that night.
If you don't have a shutter trigger then the other way that you can get a nice clear photo is to use the shutter timer. Most people think that the timer is just for getting yourself in the photo. They will look at the 2 second setting and wonder "how could anyone ever get into the shot in 2 seconds?" when looking at the different timer selections. Well you cannot, and that is not the reason for a 2 second setting. It is for triggering the camera on a shot like this.
Now I was able to press the shutter button on the camera, get my hand off the camera body, and give it time to settle down totally still before the shutter opened up. And I was able to get a completely clear photo with a longer shutter speed.
By the way, my tripod is a cheap Walmart special that I bought 25 years ago for around $50. It still works just fine after all these years. So you don't need to invest a ton of money on expensive tripods. Save on the tripod and invest in a good wired or wireless remote trigger. Some of them will even allow for repeated shots taken at a set time interval. So you can get the trigger to do double or triple duty.