What is MTF testing?
MTF refers to the measurement of the lens’s optical performance. In addition, it shows the lens ability to transmit contrast and resolve detail. MTF stands for Modulation Transfer Function. Below, we will see what MTF testing represents, how it is measured, and its uses.
The Measurement of MTF
The lens performance can vary from the centre to its extreme corners. Most lenses give a good performance in the centre but fail gradually when they arrive at the corners. Lenses that have magical optical designs are strong. However, even professional lenses depict certain optical problems.
MTF testing, therefore, takes the measurements of multiple points into account. For instance, its measurement ranges from the centre to the extreme corners of the frame.
The evaluation of the lens performance is made with the help of simple straight lines. These are generally black lines on top of a white background. The thicker lines are used for measuring the contrast, and the thinner lines are useful for measuring the resolution.
Importance of MTF as a standard way of testing
There are several engineers who believe MTF to be a standard way of testing the integrity and quality of an image. System testing becomes similar to applied actual environmental testing due to MTF. MTF can directly approach the integrated polychromatic performance of many optical systems. It is for this very reason MTF has gained importance as a standard way of testing.
MTF charts can be useful in providing information in relation to focus shift, field curvature, lens contrast and resolution, lateral chromatic aberration, and astigmatism. Therefore, with this information, one can get an idea about the actual performance of the lens. Since it is measured from the centre to the extreme corners of the frame, it can help one to get an appropriate lens evaluation.