An image, or image point or region, is in focus if light from object points is converged almost as much as possible in the image, and out of focus if light is not well converged. The border between these is sometimes defined using a "circle of confusion" criterion.

What substance absorbslightenergy during photosynthesis

In the second case, the photon gets absorbed (UV light), the photon ceases to exist, gives all its energy to the absorbing atom/electron, and then the electron relaxes in single or multiple steps, maybe with a delay, but the emitted photon has different energy than the originally absorbed photon (IR light).

Transmission oflight

Gasses are closest to atomic reactions since their complexity is only molecular in adding extra energy levels for transitions.

It depends on your definition of material. For solids, the quantum mechanical effects, i.e. energy levels that can absorb the photon, are not only on atoms. Solids are made up also by molecules and by lattices. These groupings have binding energies and the corresponding possibility of absorbing a photon and emitting a different one, distributing the energy to levels in the molecules and the lattice.

Phosphorescence is a type of photoluminescence related to fluorescence. Unlike fluorescence, a phosphorescent material does not immediately re-emit the radiation it absorbs. The slower time scales of the re-emission are associated with "forbidden" energy state transitions in quantum mechanics. As these transitions occur very slowly in certain materials, absorbed radiation is re-emitted at a lower intensity for up to several hours after the original excitation.

Now you are describing in both cases 3., absorption. The difference between the two cases is that in the first case you describe absorption, where the photon gives all its energy to the absorbing atom/electron and ceases to exist. Then, the electron relaxes in a single step and emits a photon with the same energy as the absorbed photon.

What does it mean toabsorb light

So in that scenario, the photon is essentially scattered by the electron. What happens when a material absorbs energy such that, for instance, UV light strikes a material and infrared light gets emitted from it. What is happening between the photons and the material in that case?

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Diverging (negative) lenses and convex mirrors do not focus a collimated beam to a point. Instead, the focus is the point from which the light appears to be emanating, after it travels through the lens or reflects from the mirror. A convex parabolic mirror will reflect a beam of collimated light to make it appear as if it were radiating from the focal point, or conversely, reflect rays directed toward the focus as a collimated beam. A convex elliptical mirror will reflect light directed towards one focus as if it were radiating from the other focus, both of which are behind the mirror. A convex hyperbolic mirror will reflect rays emanating from the focal point in front of the mirror as if they were emanating from the focal point behind the mirror. Conversely, it can focus rays directed at the focal point that is behind the mirror towards the focal point that is in front of the mirror as in a Cassegrain telescope.

Transmission oflightexamples

Absorption oflightExamples

So a lot can happen when a photon hits a solid material, starting with the description in the answer by Árpád Szendrei , of atomic interactions, to interacting with the total lattice. See the band theory of solids to understand the complexity. The energy of the photon will contribute to the raising of the temperature of the material and thus go towards its black body radiation.

If the material is liquid, again there are bound quantum mechanical states on which the photon can be absorbed and the energy degraded with subsequent de-excitations. It is more time and space dependent than in solids.

There are different ways an electron (atom) can relax, like in a single step. Still, the emitted photon might have a different energy level than the originally absorbed one. Especially when the relaxation happens in multiple steps, the emitted photons all have different energies than the original photon.

when materialsabsorblight, the energy transforms to _____ energy.

I'm curious what happens when light is completely absorbed by the material and what determines if it gets absorbed vs. simply scattered as described in my first paragraph.

To be clear, I'm curious what happens when light is completely absorbed by the material and what determines if it gets absorbed vs. simply scattered as described in my first paragraph.

5 things thatabsorb light

In the case of phosphorescence, the electron undergoes an intersystem crossing, usually a triplet state. This takes time, and the electron will relax in a longer period of time.

In geometrical optics, a focus, also called an image point, is a point where light rays originating from a point on the object converge.[1] Although the focus is conceptually a point, physically the focus has a spatial extent, called the blur circle. This non-ideal focusing may be caused by aberrations of the imaging optics. Even in the absence of aberrations, the smallest possible blur circle is the Airy disc caused by diffraction from the optical system's aperture; diffraction is the ultimate limit to the light focusing ability of any optical system. Aberrations tend to worsen as the aperture diameter increases, while the Airy circle is smallest for large apertures.

Now it is very important to understand that not only the number of steps of relaxation can vary, but the delay between absorption and emission too.

I'm curious how light is absorbed in materials. From what I understand, when an electron absorbs a photon, it gets excited to an energy level that is higher than the level it's in and the energy difference between the levels is equal to the energy of the photon. Then the electron spontaneously falls back to its ground state, releasing a photon with the same amount of energy.