What is the lens MTF function?
What do you mean the lens MTF function?
What is the lens MTF curve?
MTF full name is the Modulation Transfer Function, as the Modulation Transfer Function, the unit represented by the line/mm.
Comprehensive reflects the contrast and resolution of lens MTF characteristics of MTF is measured with instrument, thus it can be completely ruled out film and other objective factors and artificial interpretation of subjective factors, is currently the most accurate objective lens evaluation method.
MTF curve example above the graph example, according to A, B, C three MTF curve analysis of the following: the lens in the low frequency contrast curve A represent is moderate, but with the improvement of spatial frequency, its slow attenuation process, its quality is good.
Curve B represents the lens did very well in the low frequency, shows the contrast of the lens is very good, but with the improvement of spatial frequency, its attenuation curve soon, explain the resolution of the camera is not very good.
The lens in the low frequency curve C represent quickly decay, overall quality is low.
And the curve of the above, the manufacturer when the MTF curve drawing are fixed space frequency and aperture.
What do you think the MTF curve?
The MTF values as close to 1 as possible, that is, the MTF line jumped over higher. 2.
The higher the thick line, explains the contrast of lens performance, the better.
The higher the fine line, illustrates the lens, the better the resolution of 4.
The MTF curve is smooth, edge and center of the smaller imaging gap 5.
The closer the solid line and dotted line, the better the lens bokeh 6.
The blue line shows the lens imaging level on f / 8, similar to the best imaging lens level 7.
Black line that the lens aperture imaging level, large aperture value of MTF curve is not everything, it can only be interpretation contrast and resolution characteristic of lens, unable to distinguish features such as anti glare, distortion, so the reasonable interpretation of MTF curve at the same time, to be rational and objective point of view, the MTF is only a reference but not all.