>>3249365It entirely depends on what kinds of things you shoot. Prime lenses should really only be purchased when you know exactly what your needs are. If you don't know what you need, then stick with the kit lens and the obligatory normal prime.
10-24mm range is useful for wide angle landscapes when you need to capture a large scene and walking backwards is not practical or possible, but you can do plenty of landscape work with your 18-55. It's also good for taking pictures at parties, since you can get a big group of people without walking backwards, and the OIS helps indoors immensely.
16mm f/1.4 is a bit of a specialty lens. You can get really close up and it's good for low light, but the corners are a little soft wide open, and even when you stop it down, it has a bit of astigmatism, so it's not ideal for wide angle astrophotography. It's great for landscapes and architecture, but not the widest and the fact that it's a prime might be limiting when you are unable to zoom with your feel
56mm f/1.2 is another specialty lens. It's purpose-built for portraits, but the sharpness wide open can work against you to some degree. Most people actually prefer a little bit of soft focus in a portrait lens wide open, and the "bokeh balls" - out of focus point sources of light - can be a little dirty looking in this lens (which was corrected in the APD version). A very underrated use for a lens like this is shallow depth of field landscape photography. See: Pic related, which was taken with a full frame camera and 85mm lens, but you could emulate it with a lens like the 56mm f/1.2 on crop sensor. It's a cool effect, but ultimately, fairly niche as well.
Think about the types of shooting that you do and the ways that your 18-55 is truly inadequate at it. You may ultimately decide on a completely different lens.
