It seems you're asking about "orbs" in the context of paranormal photography. There's no scientific evidence that orbs are anything other than dust, insects, or reflections of light.

Here's why different sizes of orbs appear in photos:

* Dust particles: Dust particles come in various sizes, hence the different sizes of orbs.

* Insects: Different types of insects have different sizes, contributing to the size variations in orbs.

* Light reflections: The size of a reflection depends on the size and distance of the light source, as well as the angle and surface it's reflecting off.

It's important to note that:

* Orbs are not a reliable indicator of paranormal activity. They are a common phenomenon easily explained by natural causes.

* Claims of orbs being spirits are anecdotal and lack scientific evidence.

If you're interested in photography, you can explore techniques for minimizing orbs in your pictures by adjusting lighting, cleaning your lens, and using a flash.

Remember, critical thinking and scientific evidence are important when exploring unexplained phenomena.