Judobreaker: Does one use lower shutter speed in dark conditions, and faster shutter speed in light conditions? Doesn't shutter speed also freeze or exaggerate the appearance of motion? Blender is aperture I found out. What is that ? Thanks
Yes.
The shutter speed is the time your shutter is opened in seconds. The shutter is made by 2 curtains that open and close when pressing the button to make a photo (sort of, but the exact movements are irrelevant in this question).
The longer your shutter is opened, the more light is let into the photo, resulting in a brighter photo.
Each photo you make needs a certain amount of light to get the photo as you want it. You're not trying to get over- or underexposed photos, you're trying to get exactly the amount of light that will make your photo perfect.
This basically means that in situation with a lot of light (a sunny day for example) the shutter should be fast so not too much light gets through while in a situation with little light (late in the evening, indoors, etc.) the shutter needs to be slower because it will take longer to get the amount of light you need.
It's basically as simple as that.
However...
Like you mentioned, using certain shutter speeds can freeze or exaggerate motion. It all depends on the combination of the speed of that motion and the speed of your shutter.
Simply put: How much does the object move while your shutter is opened?
If you've got a shutter speed of 1/1000th of a second you'll be able to freeze most moving objects on the photo just fine as they simply will not move a long distance in that fraction of a second.
Then again with a shutter speed of 1/20th of a second a running person will start to become rather blurred in the photo as they do actually move some distance during that time. Lower the shutter speed to half of a second or even longer and the person will start to become a full unrecognisable blur.
The tricky thing with all this is that you need to combine the two. Both the light coming in and the movement are affected by that single shutter speed.
When trying to freeze movement in low light situations this means you will have to increase the light by some other means (opening up aperture, increasing sensor sensitivity or using a flash) because the photo will become underexposed otherwise.
When trying to get an extra blur in a situation with a lot of light you will have to decrease the light (nd-filters) to make sure the photo won't be overexposed.
I hope this helps.
