Lens focus from object and image
================================

Any optical lens creates image of an object. Distances lens-object and lens-image depend on lens optical strength.
This law is also called the **thin lens formula**.

**Conditions**

#. Lens is thin.

**Links:**

#. `Wikipedia <https://en.wikipedia.org/wiki/Lens#Lens_equation>`__.

.. py:currentmodule:: symplyphysics.laws.optics.lens_focus_from_object_and_image

.. py:data:: focus_distance

    :attr:`~symplyphysics.symbols.optics.focal_length` of the lens.

Symbol:
    :code:`f`

Latex:
    :math:`f`

Dimension:
    :code:`length`


.. py:data:: distance_to_object

    :attr:`~symplyphysics.symbols.classical_mechanics.euclidean_distance` from lens to object.

Symbol:
    :code:`d_o`

Latex:
    :math:`d_\text{o}`

Dimension:
    :code:`length`


.. py:data:: distance_to_image

    :attr:`~symplyphysics.symbols.classical_mechanics.euclidean_distance` from lens to image.

Symbol:
    :code:`d_i`

Latex:
    :math:`d_\text{i}`

Dimension:
    :code:`length`


.. py:data:: law

    :code:`1 / f = 1 / d_o + 1 / d_i`


    Latex:
        .. math::
            \frac{1}{f} = \frac{1}{d_\text{o}} + \frac{1}{d_\text{i}}