Updated: April 17, 2019 Published: May 7, 2013Please note — this article has been updated to reflect Canon’s recent changes in MTF charts, and the evaluation methods used to produce them. Introduced these changes coinciding with the launch of the EOS R mirrorless system, in late 2018.Most photography and video enthusiasts have seen “MTF” (Modulation Transfer Function) charts for different lenses, but perhaps have not been entirely clear on exactly what they communicate. We know they’re supposed to give an indication of a lens’ expected optical performance, but beyond that it may be a bit of a mystery. We’ll try to move past the technical terms and explain them here in a real-world way. MTF charts for Canon lenses can be found for each lens on the Canon USA web site.Canon and other lens makers have published MTF charts in brochures, articles and online for some time. While it’s not always possible to directly compare a chart from Company A with one from Company B (they may use different measurement standards, for instance), MTF charts are essentially similar. So if you understand how to read and assess Canon’s charts, you’ll be able to evaluate those from other sources as well.
WHY ARE MTF CHARTS SIGNIFICANT?It would be great if we could say that every lens produced is a perfect lens, but unfortunately even at the highest levels, that’s not the case. Every lens ever manufactured has some inherent limits in its ability to render perfectly-reproduced detail from a scene or subject onto a digital image sensor or piece of film. Various imperfections, under the broad umbrella of “lens aberrations,” are present even in the finest of lenses. And they’re often more prevalent in some situations than in others — at a lens’s widest aperture, for instance, it can typically be expected to show more types of visible imperfections in an image than it might with the aperture stopped down two or three stops. The same applies at the wide-angle end of a zoom lens’ range versus its telephoto end. Optical performance can and will change, at least subtly, and so on.MTF charts give the serious photographer a way to compare how some of these aberrations can impact a lens’ ability to transmit detail and contrast to the film plane or image sensor, and provide a meaningful method of making comparisons between one lens and another. MTF charts aren’t all-encompassing, nor are they the last word in assessing image quality.
We’ll mention why as we close this article. But for now, let’s begin to understand what MTF charts measure and what they tell us in the first place. HORIZONTAL AND VERTICAL COMPONENTS OF AN MTF CHARTOne inherent fact of most lenses is that their sharpness, contrast and fidelity tend to be better dead-center in an image, and slowly drop in performance as we move outward from the center toward any of the corners of a picture. At the extreme corners of an image, most lenses are performing at a lower level of total image quality than they do at the center.The first thing an MTF chart displays is the distance from the center to the corner of a “full-frame” image. All MTF charts for Canon EF, TS-E and MP-E lenses assume a full-frame image at 36x24mm in size (the same size as a traditional 35mm film negative or transparency).
Navitar's newest large format lens, the 1X Raptar Pro, has been designed specifically for large area and line scan sensors. The lens offers improved MTF over the Raptar lens series, strong relative illumination and zero distortion over a 90 mm field of view. View All Raptar Pro Models: Zeiss. Targeted at the large format camera in the market, DZO has developed lenses for 8K 16K. More than 10 lenses in this series, which can be perfectly applied in the inspection of PCB, LCD, LED, OLED screen, SPI, AOI and printing.
Canon MTF charts for EF-S and EF-M lenses — made exclusively for smaller APS-C sensor cameras, such as the EOS Rebel series and EOS M-series — takes this into account and measure a smaller diagonal area. On a full-frame camera, a lens is expected to render a good image from center to corner.
This distance is 21.6mm, and MTF measurements are taken along this diagonal line.On a full-frame sensor, 36x24mm in size, the distance of a diagonal line from the center to one corner is 21.6mm (one-half of the diagonal of the full frame area). So, along the bottom horizontal axis of a Canon MTF chart, you’ll see markings starting at zero and moving past 20mm to include this 21.6mm center-to-corner distance of a full-frame image sensor. This is sometimes referred to as “image height.”.
MTF charts are marked with the distance being measured from center of the image, along the bottom axis. The farther the measurements are from the center — in other words, the further to the right on an MTF chart — the harder it is for most lenses to maintain constant high quality.In the vertical axis, you’ll see indications from zero at the bottom to “1” at the top.
These indicate the relative fidelity and optical quality level. The higher a curve on an MTF chart is, the better it’s performing in the areas the chart is measuring.An MTF chart begins by measuring optical performance at the center of the picture area and then measures repeatedly along a diagonal line, further and further toward the corners of the image. The quality measurements obtained are then plotted on the MTF graph, showing you how far from the center they’re taken from as you look from left to right on the chart. The farther to the right, the closer to the corner the measurement is. And the higher on the scale the resulting lines are, the better the MTF characteristics of that lens are.
The higher an MTF curve appears, the better the image reproduction quality at that area. CONTRAST AND RESOLUTION — THE TWO ITEMS MEASURED BY MTFCanon engineers use sophisticated computer techniques to generate MTF data across the entire image area, based on design values of the optical formula. By calculating how well a lens can reproduce patterns of fine repeating lines, its optical limits can be determined and become part of an MTF chart’s information. Obviously, the better a lens’ optical performance, the more accurately it can display these precise, fine lines.While a photographer might simply think that one test to measure “sharpness” would give all the information he or she would need, there is more to it than that. Most optical engineers agree that in evaluating a lens’ optical performance, there are two distinctly different aspects to overall lens quality — contrast and resolution. They may sound like the same thing, but they’re not. And MTF charts are intended to display the differences between these two key factors.
Understanding Contrast: Simply stated, contrast is a lens’ ability to display a clear distinction between dark and light subject levels, both on an MTF chart and on an imaging sensor (or piece of film). When the dark edge of a fine black line ends and the adjacent white background area begins, a perfect lens would theoretically provide a total shift from black to white information with no fuzziness and blends into shades of gray, and so on. Not all lenses can render this sudden shift cleanly, or they may do it better at the center of a picture than at the outer edges or corners. Resolution: Again, it may seem like we’re speaking of the same thing, but there are definite differences to an optical engineer or lens designer. Resolution measures the ability of a lens to precisely reproduce a fine subject point and, in a general sense, gives an idea of a lens’ ability to render extremely fine detail. Thicker lines measure a lens’ contrast; thin repeating lines measure its resolution or ability to render fine detail.Contrast is measured by testing how a lens performs with broader and thicker sets of lines. These are spaced at a rate of 10 lines per millimeter (lpm).
Free escape velocity nova licence code software, best escape velocity nova licence code download at - Escape Velocity: Nova for Mac. Escape Velocity: Nova for Mac 1.1.EV Nova is the third game in the Escape Velocity series, and is by far the most ambitious installment to date. Ev Nova License Code Posted:admin. EV Nova is the third game in the Escape Velocity series. With a completely redesigned gaming engine, EV Nova thrusts you into a sprawling universe dominated by a myriad of warring factions, each sharing a common bond, but so philosophically different as to make conflict inevitable. It's best if you avoid. Entering your EV Nova registration code is still possible In a nutshell: if you have a registration key for EV Nova and still know the moment when Ambrosia sent you this key (within an accuracy of a few days), you can still register new installs of the game if you set your computer's clock to a time just after that moment. Ev nova license code free. Download now the serial number for EV Nova 1.0.8. All serial numbers are genuine and you can find more results in our database for EV software. Updates are issued periodically and new results might be added for this applications from our community. To improve your results for Ev Nova 1.1.1 do not include words such as serial number key etc. In your search, excluding those words will result in better results. Make sure your spelling for Ev Nova 1.1.1 is correct, you might also want to try searching without including the version number. If you still arent able to find what you are looking for you can try the sponsored files above they.
While that sounds super thin, they are relatively thick for optical test purposes. The lens’ ability to display a clean consistent break between the line and its adjacent background is repeatedly measured, starting at the center of an image then working its way toward the far corners.Resolution, the lens’s ability to render extremely fine detail, is measured with similar sets of repeating lines, but they’re much finer. Spaced at 30 lines per millimeter, these super thin lines will make or break a lens’ ability to record and display fine detail in actual images. When a lens reaches the limits of its resolving power, these repeating lines will no longer appear distinct and will seem to blur together when reviewed by engineers. Resolution is evaluated separately from contrast and the results of the two separate assessments are then plotted on the MTF charts we see online and elsewhere.
UNDERSTANDING SAGITTAL AND MERIDIONAL TEST PATTERNSIt would be natural to assume that a good lens would produce the same “sharpness” results for patterns of parallel repeating lines, no matter what direction the lines were oriented. However, in real-world conditions, that’s not the case — even with some of the finest lenses in the world. Lines running parallel to a diagonal line from the center of an image to one of its corners are often easier for a lens to reproduce accurately and consistently. In fact, some lenses show a marked difference in cleanly reproducing lines arranged perpendicular (90˚) to this diagonal direction. MTF charts display these variations and they’re an important part of what MTF data tells us.
Most lenses display differing contrast and resolution with Sagittal lines, running parallel to a diagonal drawn from center to corner of an image, than they do with Meridional lines. Repeating patterns of both are tested, starting at the center of a lens’ image and moving progressively outward to its corners.The technical term for lines arranged parallel to a diagonal line from center to corner of the film or image sensor area is “ Sagittal.” You can think of Sagittal lines as like spokes on a wheel, radiating outward from the center of the image area.Lines perpendicular to this are called “ Meridional.” Again, using the wheel analogy for a moment, Meridional lines would run in the direction of the outer, circular edge of the wheel.
A typical Canon MTF chart, from a hypothetical lens.
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Updated: April 17, 2019 Published: May 7, 2013Please note — this article has been updated to reflect Canon’s recent changes in MTF charts, and the evaluation methods used to produce them. Introduced these changes coinciding with the launch of the EOS R mirrorless system, in late 2018.Most photography and video enthusiasts have seen “MTF” (Modulation Transfer Function) charts for different lenses, but perhaps have not been entirely clear on exactly what they communicate. We know they’re supposed to give an indication of a lens’ expected optical performance, but beyond that it may be a bit of a mystery. We’ll try to move past the technical terms and explain them here in a real-world way. MTF charts for Canon lenses can be found for each lens on the Canon USA web site.Canon and other lens makers have published MTF charts in brochures, articles and online for some time. While it’s not always possible to directly compare a chart from Company A with one from Company B (they may use different measurement standards, for instance), MTF charts are essentially similar. So if you understand how to read and assess Canon’s charts, you’ll be able to evaluate those from other sources as well.
WHY ARE MTF CHARTS SIGNIFICANT?It would be great if we could say that every lens produced is a perfect lens, but unfortunately even at the highest levels, that’s not the case. Every lens ever manufactured has some inherent limits in its ability to render perfectly-reproduced detail from a scene or subject onto a digital image sensor or piece of film. Various imperfections, under the broad umbrella of “lens aberrations,” are present even in the finest of lenses. And they’re often more prevalent in some situations than in others — at a lens’s widest aperture, for instance, it can typically be expected to show more types of visible imperfections in an image than it might with the aperture stopped down two or three stops. The same applies at the wide-angle end of a zoom lens’ range versus its telephoto end. Optical performance can and will change, at least subtly, and so on.MTF charts give the serious photographer a way to compare how some of these aberrations can impact a lens’ ability to transmit detail and contrast to the film plane or image sensor, and provide a meaningful method of making comparisons between one lens and another. MTF charts aren’t all-encompassing, nor are they the last word in assessing image quality.
We’ll mention why as we close this article. But for now, let’s begin to understand what MTF charts measure and what they tell us in the first place. HORIZONTAL AND VERTICAL COMPONENTS OF AN MTF CHARTOne inherent fact of most lenses is that their sharpness, contrast and fidelity tend to be better dead-center in an image, and slowly drop in performance as we move outward from the center toward any of the corners of a picture. At the extreme corners of an image, most lenses are performing at a lower level of total image quality than they do at the center.The first thing an MTF chart displays is the distance from the center to the corner of a “full-frame” image. All MTF charts for Canon EF, TS-E and MP-E lenses assume a full-frame image at 36x24mm in size (the same size as a traditional 35mm film negative or transparency).
Navitar's newest large format lens, the 1X Raptar Pro, has been designed specifically for large area and line scan sensors. The lens offers improved MTF over the Raptar lens series, strong relative illumination and zero distortion over a 90 mm field of view. View All Raptar Pro Models: Zeiss. Targeted at the large format camera in the market, DZO has developed lenses for 8K 16K. More than 10 lenses in this series, which can be perfectly applied in the inspection of PCB, LCD, LED, OLED screen, SPI, AOI and printing.
Canon MTF charts for EF-S and EF-M lenses — made exclusively for smaller APS-C sensor cameras, such as the EOS Rebel series and EOS M-series — takes this into account and measure a smaller diagonal area. On a full-frame camera, a lens is expected to render a good image from center to corner.
This distance is 21.6mm, and MTF measurements are taken along this diagonal line.On a full-frame sensor, 36x24mm in size, the distance of a diagonal line from the center to one corner is 21.6mm (one-half of the diagonal of the full frame area). So, along the bottom horizontal axis of a Canon MTF chart, you’ll see markings starting at zero and moving past 20mm to include this 21.6mm center-to-corner distance of a full-frame image sensor. This is sometimes referred to as “image height.”.
MTF charts are marked with the distance being measured from center of the image, along the bottom axis. The farther the measurements are from the center — in other words, the further to the right on an MTF chart — the harder it is for most lenses to maintain constant high quality.In the vertical axis, you’ll see indications from zero at the bottom to “1” at the top.
These indicate the relative fidelity and optical quality level. The higher a curve on an MTF chart is, the better it’s performing in the areas the chart is measuring.An MTF chart begins by measuring optical performance at the center of the picture area and then measures repeatedly along a diagonal line, further and further toward the corners of the image. The quality measurements obtained are then plotted on the MTF graph, showing you how far from the center they’re taken from as you look from left to right on the chart. The farther to the right, the closer to the corner the measurement is. And the higher on the scale the resulting lines are, the better the MTF characteristics of that lens are.
The higher an MTF curve appears, the better the image reproduction quality at that area. CONTRAST AND RESOLUTION — THE TWO ITEMS MEASURED BY MTFCanon engineers use sophisticated computer techniques to generate MTF data across the entire image area, based on design values of the optical formula. By calculating how well a lens can reproduce patterns of fine repeating lines, its optical limits can be determined and become part of an MTF chart’s information. Obviously, the better a lens’ optical performance, the more accurately it can display these precise, fine lines.While a photographer might simply think that one test to measure “sharpness” would give all the information he or she would need, there is more to it than that. Most optical engineers agree that in evaluating a lens’ optical performance, there are two distinctly different aspects to overall lens quality — contrast and resolution. They may sound like the same thing, but they’re not. And MTF charts are intended to display the differences between these two key factors.
Understanding Contrast: Simply stated, contrast is a lens’ ability to display a clear distinction between dark and light subject levels, both on an MTF chart and on an imaging sensor (or piece of film). When the dark edge of a fine black line ends and the adjacent white background area begins, a perfect lens would theoretically provide a total shift from black to white information with no fuzziness and blends into shades of gray, and so on. Not all lenses can render this sudden shift cleanly, or they may do it better at the center of a picture than at the outer edges or corners. Resolution: Again, it may seem like we’re speaking of the same thing, but there are definite differences to an optical engineer or lens designer. Resolution measures the ability of a lens to precisely reproduce a fine subject point and, in a general sense, gives an idea of a lens’ ability to render extremely fine detail. Thicker lines measure a lens’ contrast; thin repeating lines measure its resolution or ability to render fine detail.Contrast is measured by testing how a lens performs with broader and thicker sets of lines. These are spaced at a rate of 10 lines per millimeter (lpm).
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While that sounds super thin, they are relatively thick for optical test purposes. The lens’ ability to display a clean consistent break between the line and its adjacent background is repeatedly measured, starting at the center of an image then working its way toward the far corners.Resolution, the lens’s ability to render extremely fine detail, is measured with similar sets of repeating lines, but they’re much finer. Spaced at 30 lines per millimeter, these super thin lines will make or break a lens’ ability to record and display fine detail in actual images. When a lens reaches the limits of its resolving power, these repeating lines will no longer appear distinct and will seem to blur together when reviewed by engineers. Resolution is evaluated separately from contrast and the results of the two separate assessments are then plotted on the MTF charts we see online and elsewhere.
UNDERSTANDING SAGITTAL AND MERIDIONAL TEST PATTERNSIt would be natural to assume that a good lens would produce the same “sharpness” results for patterns of parallel repeating lines, no matter what direction the lines were oriented. However, in real-world conditions, that’s not the case — even with some of the finest lenses in the world. Lines running parallel to a diagonal line from the center of an image to one of its corners are often easier for a lens to reproduce accurately and consistently. In fact, some lenses show a marked difference in cleanly reproducing lines arranged perpendicular (90˚) to this diagonal direction. MTF charts display these variations and they’re an important part of what MTF data tells us.
Most lenses display differing contrast and resolution with Sagittal lines, running parallel to a diagonal drawn from center to corner of an image, than they do with Meridional lines. Repeating patterns of both are tested, starting at the center of a lens’ image and moving progressively outward to its corners.The technical term for lines arranged parallel to a diagonal line from center to corner of the film or image sensor area is “ Sagittal.” You can think of Sagittal lines as like spokes on a wheel, radiating outward from the center of the image area.Lines perpendicular to this are called “ Meridional.” Again, using the wheel analogy for a moment, Meridional lines would run in the direction of the outer, circular edge of the wheel.
A typical Canon MTF chart, from a hypothetical lens.