Test chart suitability for MTF measurements

Related pages: Compensating camera MTF measurements for chart and sensor MTF –  Introduction – Calculation – MTF compensation files – Applying the compensation – Lens MTF measurements Chart Quality Calculator – determine the suitability of a chart (based on MTF measurements for specific media & print methods) for a specific application   Sharpness assumption  |  Chart suitability display  |  Using the figure  Inkjet matte  |  B&W […]

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Slanted-edge MTF measurement consistency

Note: This page is not quite complete, but we felt that the results are important enough to be presented in its present (nearly complete) state. Method – Results – MTF50 failure – MTF Area Related page: Correcting Misleading Image Quality Measurements: links to an Electronic Imaging paper that compares MTF summary metrics In this page we analyze […]

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Summary Metrics Derived from the MTF Curve

Summary Metric Description Comments MTF50 MTFnn Spatial frequency where MTF is 50% (nn%) of the low (0) frequency MTF. MTF50 (nn = 50) is widely used because it corresponds to bandwidth (the half-power frequency) in electrical engineering. The most common summary metric; correlates well with perceived sharpness. Increases with increasing software sharpening; may be misleading because […]

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Interpreting MTF50

What MTF50 is Needed for Prints?  Determining MTF50 depends on the print size. If you plan to print large posters (20 × 30 inches or over), the more MTF50, the sharper your prints will appear. Any high-quality, 4+ megapixel digital camera (that is, one that produces good test results; MTF50(corr) > 0.3 cycles/pixel) is capable […]

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MTF Measurement Matrix

Imatest measures MTF using a variety of techniques (see table below), each of which gives different results in imaging systems because image processing depends on local scene content that is rarely constant throughout an image. Sharpening (high frequency boost) tends to be maximum near high-contrast features, while noise reduction (high frequency cut, which can obscure […]

Read More

SFR results: Edge and MTF (Sharpness) plot

A key result of the SFR, SFRplus, and eSFR ISO modules If you entered Imatest on this page, you may want to explore the background information in these links.       Sharpness introduces sharpness measurements and MTF.       How to test Lenses with Imatest contains concise instructions on testing lenses            using SFRplus and eSFR […]

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MTF Compare

Compare MTFs of individual edge regions in different cameras and lenses Introduction to MTF Compare MTF Compare (not included in Imatest Studio), is a post-processor for comparing the MTFs of different cameras, lenses, and imaging systems that have been analyzed by SFR, Rescharts Slanted-edge SFR, SFRplus, or eSFR ISO, and had results saved in CSV […]

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MTF curves and Image appearance

Correlating measurement with appearance Modulation Transfer Function (MTF) is a fundamental measure of imaging system sharpness. It is introduced in Sharpness and discussed further in Sharpening. MTF is measured by Imatest SFR, SFRplus, and by several Rescharts modules. The most frequent questions that arise in sharpness (MTF) testing are “What does the MTF curve mean?” […]

Read More

MTF Compare

Introduction to MTF Compare MTF Compare, a module of Imatest Master,  is a post-processor for comparing the MTFs of different cameras, lenses, and imaging systems after they have been analyzed by SFR or Rescharts Slanted-edge SFR and had results saved in CSV files. Comparisons are displayed as quotients of MTFs, i.e., transfer functions. For two […]

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Compensating camera MTF measurements for chart and sensor MTF

Summary— Starting with Imatest 5.1 MTF measurements can be compensated for measured chart quality. Chart MTF compensation can double the megapixel suitability of a test chart. Results taken with different test charts will be more consistent. An approximate lens MTF calculation (independent of chart MTF compensation) has been added. It is based on a geometrical […]

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Compensating camera MTF measurements for chart and sensor MTF

Summary— Starting with Imatest 5.1 MTF measurements can be compensated for measured chart quality. Chart MTF compensation can double the megapixel suitability of a test chart. Results taken with different test charts will be more consistent. An approximate lens MTF calculation (independent of chart MTF compensation) has been added. It is based on a geometrical […]

Read More

Test chart suitability for MTF measurements

Related pages: Compensating camera MTF measurements for chart and sensor MTF –  Introduction – Calculation – MTF compensation files – Applying the compensation – Lens MTF measurements Chart Quality Calculator – determine the suitability of a chart (based on MTF measurements for specific media & print methods) for a specific application   Sharpness assumption  |  Chart suitability display  |  Using the figure  Inkjet matte  |  B&W […]

Read More

Slanted-edge MTF measurement consistency

Note: This page is not quite complete, but we felt that the results are important enough to be presented in its present (nearly complete) state. Method – Results – MTF50 failure – MTF Area Related page: Correcting Misleading Image Quality Measurements: links to an Electronic Imaging paper that compares MTF summary metrics In this page we analyze […]

Read More

Interpreting MTF50

What MTF50 is Needed for Prints?  Determining MTF50 depends on the print size. If you plan to print large posters (20 × 30 inches or over), the more MTF50, the sharper your prints will appear. Any high-quality, 4+ megapixel digital camera (that is, one that produces good test results; MTF50(corr) > 0.3 cycles/pixel) is capable […]

Read More

Summary Metrics Derived from the MTF Curve

Summary Metric Description Comments MTF50 MTFnn Spatial frequency where MTF is 50% (nn%) of the low (0) frequency MTF. MTF50 (nn = 50) is widely used because it corresponds to bandwidth (the half-power frequency) in electrical engineering. The most common summary metric; correlates well with perceived sharpness. Increases with increasing software sharpening; may be misleading because […]

Read More

MTF Measurement Matrix

Imatest measures MTF using a variety of techniques (see table below), each of which gives different results in imaging systems because image processing depends on local scene content that is rarely constant throughout an image. Sharpening (high frequency boost) tends to be maximum near high-contrast features, while noise reduction (high frequency cut, which can obscure […]

Read More

SFR results: Edge and MTF (Sharpness) plot

A key result of the SFR, SFRplus, and eSFR ISO modules If you entered Imatest on this page, you may want to explore the background information in these links.       Sharpness introduces sharpness measurements and MTF.       How to test Lenses with Imatest contains concise instructions on testing lenses            using SFRplus and eSFR […]

Read More

MTF Compare

Compare MTFs of individual edge regions in different cameras and lenses Introduction to MTF Compare MTF Compare (not included in Imatest Studio), is a post-processor for comparing the MTFs of different cameras, lenses, and imaging systems that have been analyzed by SFR, Rescharts Slanted-edge SFR, SFRplus, or eSFR ISO, and had results saved in CSV […]

Read More

MTF curves and Image appearance

Correlating measurement with appearance Modulation Transfer Function (MTF) is a fundamental measure of imaging system sharpness. It is introduced in Sharpness and discussed further in Sharpening. MTF is measured by Imatest SFR, SFRplus, and by several Rescharts modules. The most frequent questions that arise in sharpness (MTF) testing are “What does the MTF curve mean?” […]

Read More

MTF Compare

Introduction to MTF Compare MTF Compare, a module of Imatest Master,  is a post-processor for comparing the MTFs of different cameras, lenses, and imaging systems after they have been analyzed by SFR or Rescharts Slanted-edge SFR and had results saved in CSV files. Comparisons are displayed as quotients of MTFs, i.e., transfer functions. For two […]

Read More