This will depend on the characteristics and properties you value in your lens filters.
Screw on circular filters, as the name indicates, are made to be screwed on your lens threads and they’re relatively discrete and take up minimal room in your kit when you’re storing them.
A square filter is shaped like a rectangle that exceeds the size of the lens thread area. A filter adapter that screws into your lens and holds the square filter on the other side is needed for attachment. Because of the size of the square lens glass, they are larger and take up a bit more room in your kit
- Can be left on your lens for instant use
- Can be easily stacked with other filters by screwing them together
- Smaller and lighter than square filters, which makes them easier to store and use
- They are able to seal and protect the front of the lens, keeping out dirt, dust, and grime, and avoiding any problems with light leakage
- They can only fit a specified thread size (when getting a different thread size lens, you’ll need to get a new filter)
- They can fit multiple lenses with adapter rings
- They are less likely to cause vignetting
- Easier to stack with other square filters
- Larger and more bulky than circular filters
- Take up more room in your kit
- Slower to fit and use