Optical Magnification Calculator
Finds signed transverse magnification from image and object distances. Changing an input refreshes the result and its checking path.
Enter the ray measurements
Optical magnification
What the optical result represents
Finds signed transverse magnification from image and object distances. The calculation keeps image distance, object distance visible and reports optical magnification in ratio.
The sign describes image orientation while the magnitude describes the image-to-object size ratio.
The optical magnification page labels each value before it enters the equation. That prevents an angle convention, temperature scale, optical sign, or reference quantity from becoming an invisible assumption.
Following m = −di / do
For optical magnification, identify optical magnification as the sought quantity and copy the printed relationship before using the sample data. This establishes an auditable direction for the arithmetic.
Arrange m = −di / do around optical magnification before inserting the example values. This keeps the physical direction of the calculation visible.
Trace the ray before trusting the algebra
Reduce the dimensions in m = −di / do until they agree with ratio. For logarithms, trigonometric functions, and ratios, also verify that their arguments are dimensionless and inside the permitted domain.
Change one source value slightly and predict the direction of optical magnification first. If the screen moves the other way, revisit the equation, signs, and reference frame.
Using optical magnification beyond this page
Keep guard digits in optical magnification while it feeds another optics calculation, then round to the precision supported by the measurements.
Record the operating condition, formula, units, and convention beside optical magnification. Those details distinguish a physically reproducible answer from a number copied out of context.
Verify the Optical Magnification example
The starting condition is Image distance = 0.6 m; Object distance = 0.3 m. It gives a fixed reference result before any input is changed.
After solving for optical magnification, rearrange m = −di / do for one entered quantity. Recovering that entry checks a different algebraic direction instead of repeating the same calculation.
Scope of the Optical Magnification equation
The optical magnification relationship uses paraxial rays or an ideal interference geometry. Thick elements, aberrations, polarization, dispersion, and large angles may require a more complete optical model for optical magnification.
If the omitted effects are significant, replace the optical magnification equation before recalculating.
Following optical magnification into another equation
Related measurements can continue with thin lens image distance calculator, spherical mirror equation calculator and thin lens focal length calculator.
The most useful continuation is determined by the next unknown, not by superficial similarity to Optical Magnification.
Clarifying the Optical Magnification model
What does optical magnification represent?
It is the value of m = −di / do under the units, field meanings, and optics assumptions printed on the optical magnification page.
How can optical magnification be checked?
Rearrange m = −di / do to recover an entered value, reduce the surviving unit to ratio, and compare the scale with the physical setup.
Do the displayed units matter?
Yes. Convert each measurement to the unit beside its field before evaluating the optical magnification relationship.
Why might another optical magnification differ?
Another medium, temperature, geometry, reference frame, boundary condition, or sign convention can change the reported optical magnification.
Can optical magnification be negative?
On the optical magnification page, a negative value is meaningful only when the printed sign convention and equation permit it; otherwise it signals an invalid domain.