...that calls for a DSLR. Get it fitted with a prime/standard lens with at least f/1.4.
Others do not have a big enough aperture to get in enough light, and small sensors produce noisy pictues at higher ISO, sometimes to the point of being useless.
I would like to shoot object with light projected onto it's surface (dots or lines) in dark environment. The object is small similar to the size of mobile phone. How can I archive good result on the light spots? most of them are blur or the color is not clear some blue color at the edge or strong white color in the middle of the spots.
What setting on the camera is suitable?
What camera should I buy? (the budget is around $400 us to $800 us)
Another setting on the light spot or environment should I take care?