Partial Evaluation of Hassu lab-MTF test results

After measuring the MTF value curve of each lens, the Hassu lab developed a calculation method for the average value of the MTF. First, the preset focal length is used to calculate the MTF value of the lens F4, multiply by the focusing coefficient of 0.4 and 0.6 respectively to obtain the MTF value of a first-line frequency, and then multiply the average value of the 10-line/millimeter value by the focusing coefficient of 0.57, the average value of the 20-wire pair/millimeter is multiplied by the focusing factor of 0.29, and the average value of the 40-wire pair/millimeter is multiplied by the focusing factor of 0.14. After the three digits are added, the average value of the focusing value of the lens is obtained. Score the lens based on these values. Scores range from 0 to 5, so that the scores of various lenses are clearly displayed. Unlike some test results, they give a good impression but lose the guiding significance.

1. Top-level Lens

Canon EF 200mm F1.8L

Canon EF 200 F1.8L sample

Of the hundreds of 35mm million camera lenses produced worldwide, only 19 can be included in the top-level head (score more than 4.5, that is, the average value of MTF is more than 0.86 ). All these lenses are fixed focal points. There are 8 standard lenses (two with Macro, 75 ~ There are 4 models in the 85mm focal length head, 90 ~ There are 6 135mm focal lengths (three with microdistances), with the highest score of 200mm/1.8mm/4.8mm (0.89 points, the average value of MTF is ). According to the manufacturer's division, Leica lens accounted for six models (M series: 50/2, 75/1. 4, 90/2.8; R series: 50/2, 90/2. 8,100/2.8 Macro), four paragraph (50/1. 7, 50/1.4, 85/1. 1.2/2G), three canon models (EF85/200/1, EF135/2, EF. 8), three bind models (50/1. 2.8/85/1 Macro. 4). Two Models (AF 50/2. 8 Macro, AF 100/2. 8 Macro), Tuli A (MF AT-X 90/2. 5 Macro ). Not one shot was shortlisted by the powerful Nikon.

Two colors Leica M 50mm F2.0

Leica M 75mm F1.4

If you only consider the average value (focusing on the enlargement of 24-inch photos) of the 40-wire to/millimeter, The 50/1. 7 and 45/2G series headers with the best image quality at f8 are considered. They focused on the average value of the 40-wire/millimeter MTF to 0.73 and 0.72, respectively. This means that the two lenses are used to take the necessary shockproof measures. During f8, The 35mm camera can take the best image that can be enlarged to a 24-inch image. At maximum aperture, the optimal lens can be assigned to the Leica M50/2 header, and its MTF focuses on an average of 0.50.
Among all the large aperture portraits, Pentax's manual focus 85/1. 4 lens has a weak advantage. This is because the average value of MTF in the maximum aperture is 0.43, and the average value of mtf in the f8 of the amateur zoom lens is reached. Although the average value of MTF in f8 is slightly lower than that in Canon EF85/1.2 and kangtaishi 85/1. 4, considering that portraits use a large aperture, the top priority should be clear conscience.

2. Professional Lens

October 28 ~ 85 F3.3-4

In common professional-level standard zoom lenses, the time ranges from 28 ~ 85/3. 3-4 ranking first, qima AF28 ~ 70/2. 8 is the last place. The specific order is as follows:

Lens	Score	Average MTF Value
Contax 28 ~ 85/3. 3-4	4.0	0.81
Canon EF 28 ~ 70/2. 8 L	3.9	0.81
Nikon AF 35 ~ 70/2. 8	3.8	0.79
Minolta AF 28 ~ 70/2. 8	3.7	0.78
Sigma AF 28 ~ 70/2. 8 EX Asp	3.5	0.77
Leica 28 ~ 70/3. 5-4.5	3.2	0.75
Tokina AF 28 ~ 70/2-2.8 Pro	3.1	0.73
Sigma AF 28 ~ 70/2. 8	3.0	0.73

Tenglong's AF 28 ~ 105/2. 8 LD professional lens with a score of only 2.4 and a value of 0.67 MTF.Nikon AF-S 28 ~ The MTF value of 70/2. 8 ED has not been tested.
　　
Leica 80 ~ The best shot is 200/4. The positions of various lenses are arranged as follows:

Lens	Score	Average MTF Value
Leica 80 ~ 200/4	4.2	0.83
Nikon AF-S 80 ~ 200/2. 8D IF-ED	4.1	0.82
Canon EF 70 ~ 200/2. 8 L	4.1	0.82
Sigma AF 70 ~ 200/2. 8 Apo EX	3.9	0.81
Minolta AF 80 ~ 200/2. 8 Apo	3.9	0.81
Nikon AF 80 ~ 200/2. 8 D ED	3.9	0.80
Contax 80 ~ 200/4	3.8	0.79
Tokina AF 80 ~ 200/2. 8	3.4	0.76
Leica 70 ~ 210/4	3.3	0.75
Pentax FA 80 ~ 200/2. 8	3.2	0.74

EF 35 ~ 350/3-5.6 L lens, in 35 ~ The fifth segment has a very good performance, but has a moderate performance on the remote camera end, with only the level of amateur head. The overall score of this shot is 3.3 points, and the average value of the MTF focus is 0.76. Tuli's AF 100 ~ The 300/4 Pro lens score is 3.1 points, and the average value of the MTF focus is 0.74.

3. amateur videos
In popular amateur standard zoom lenses, Canon and Pentax have the highest scores. See the table below:
　　

Lens brand specifications	Score	Average MTF Value
Canon EF 28 ~ 105/3. 5-4.5 U	3.3	0.75
Pentax FA 28 ~ 70/4 AL	3.3	0.75
Canon EF 28 ~ 80/3. 5-5.6 U	3.2	0.74
Canon EF 28 ~ 80/3. 5-5.6 II U	3.1	0.73
Ricoh P 35 ~ 70/3. 4-4.5	3.1	0.73
Nikon AF 28 ~ 80/3. 5-5.6 D	3.0	0.72
Tamron AF 28 ~ 80/3. 5-5.6 Asp	3.0	0.72
Nikon AF 28 ~ 85/3. 5-4.5	2.9	0.72
Minolta MD 28 ~ 70/3. 5-4.8	2.9	0.71
Contax 28 ~ 70/3. 5-4.5	2.8	0.71
Nikon AF 28 ~ 70/3. 5-4.5 D	2.8	0.71
Sigma AF 28 ~ 80/3-5.6 Macro	2.7	0.70
Minolta AF 28 ~ 80/3. 5-5.6	2.7	0.70
Ricoh 35 ~ 70/3. 5-4.8	2.6	0.69
Pentax FA 28 ~ 80/3. 5-4.7	2.3	0.66
Pentax FA 28 ~ 80/3. 5-5.6	2.0	0.64
Vivitar AF 28 ~ 80/3. 5-5.6	1.8	0.62

In popular amateur telephoto zoom lenses, Minolta AF 100 ~ 300/4. 5-has the highest score. See the table below:

Lens brand specifications	Score	Average MTF Value
Minolta AF 100 ~ 300/4-5.6 APO	3.2	0.74
Canon EF 70 ~ 210/3. 5-4.5 U	3.1	0.74
Vivitar 70 ~ 210/2. 8-4 Series 1	3.0	0.73
Sigma 70 ~ 210/4-5.6	2.9	0.72
Pentax FA 70 ~ 200/4-5.6	2.9	0.72
Minolta AF 70 ~ 210/3. 5-4.5	2.9	0.72
Nikon AF 70 ~ 210/4-5.6 D	2.8	0.71
Minolta AF 70 ~ 210/4. 5-5.6	2.7	0.69
Yashica AF 70 ~ 210/4. 5	2.7	0.69
Ricoh P 70 ~ 210/4. 5-5.6	2.6	0.69
Minolta AF 80 ~ 200/4. 5-5.6	2.6	0.69
Canon EF 100 ~ 300/4. 5-5.6 U	2.4	0.67
Pentax FA 100 ~ 300/4. 5-5.6	2.4	0.67

4. Ultra Wide-angle zoom lens (no matter how professional you are ):

Tenglong sp af 20 ~ 40/2. 7-3.5

　　

Lens brand specifications	Score	Average MTF Value
Tamron sp af 20 ~ 40/2. 7-3.5	3.7	0.78
Nikon AF 20 ~ 35/2. 8 D IF	3.6	0.78
Canon EF 20 ~ 35/2. 8 L	3.5	0.77
Sigma AF 21 ~ 35/3. 5-4.2	3.5	0.77
Canon EF 20 ~ 35/3. 5-4.5 U	3.4	0.76
Pentax FA 20 ~ 35/4 AL	3.4	0.76
Minolta AF 17 ~ 35/2. 8G	3.3	0.75
Tokina AF 20 ~ 35/3. 5-4.5	3.3	0.75
Canon 20 ~ 35/3. 5 L	3.3	0.75
Canon EF 17 ~ 35/2. 8 L	3.2	0.74
Sigma AF 17 ~ 35/2. 8-4 EX	3.1	0.73
Vivitar AF 19 ~ 35/3. 5-4.5	2.9	0.72
Minolta AF 20 ~ 35/3. 5-4.5	2.8	0.71
Pentax Fisheye 17 ~ 28/3. 5-4.5	2.7	0.70
Tokina AF 20 ~ 35/2. 8 Pro	2.5	0.68
Sigma 21 ~ 35/3-4.2 MF	2.4	0.67

5. Special zoom lensSome of the most popular special zoom headers on the market have low scores, such as Nikon 24 ~ 120/3. 5-5.6 d if only 2.3 points, the average value of MTF focus only 0.66, tenglong AF 28 ~ 200/3-5.6 LD (Asp Super) scored 2.7 points, and the average value of MTF was 0.70. It is Canon's new anti-shake lens EF 28 ~ 135/3-5 ~ The 5.6 is u score reached 3.5 points, and the average value of MTF was 0.77, which entered the ranks of professional imaging.

6. Confirmation of rumors
Some comparisons also confirm some conclusions made by the photography industry through practical experience. The German lens is indeed of extraordinary quality. Among the 19 top-level lenses, Leica accounts for 6 and contec (Germany-Japan Cooperation) accounts for four. However, it does not have much advantage over other Professional-level lenses, and shows a lower cost-performance ratio. It is also said that the Nikon manual focus lens is better than the automatic focus lens. Tested Nikon F35 ~ 135/3. 5-4.5 and F35 ~ 70/3. 5-3.3 shot scores all reached 0.75 points. The average value of MTF is, while that of AF35 to AF35 ~ 135/3. 5-4.5 and AF35 ~ 70/3. The scores of the 5-2.6 lens were only 0.69, and the average value of the MTF focus was only. The imaging quality was indeed reduced a lot. It is said that Pentax's camera quality is above Minolta. Now it seems that Pentax's manual camera is really good, but it also has a few satellites, but the automatic camera is normal. For example, 80 to 14 thousand yuan ~ 200/2. 8 Professional, scored only 3.2 points, less than the price of only 5100 yuan Tui 80 ~ 200/2. 8. Its amateur standard and far-camera zoom lenses all rank at the last few of the same level, which is why Pentax's camera reputation is getting smaller and smaller. The camera has sprung up in recent years ~ The 70/2. 8EX lens is 0.5 points higher than the original lens of the same level. 70 ~ The 200/2. 8 Apo EX camera has been in parallel with Nikon and Meida's camera, far higher than touli, a former competitor.

Sigma 70 ~ 200/2. 8 Apo EX

Of course, the MTF value of the lens is not omnipotent. It does not show the distortion and glare of the lens, so it cannot describe everything in the lens. However, it is indeed the most scientific and comprehensive indicator to present the lens optical capabilities. You have mastered the MTF Curve of the lens, that is, you can buy the lens with the best performance and price ratio. You can also use the instructions of the lens curve to raise your lens length as much as possible in photography to avoid the short lens length, shooting in a good MTF value segment makes the best use of all things

The function of the lens's MTF value in analyzing and judging the imaging quality of a lens has been elaborated in detail by Qilin and others in different magazine newspapers. However, due to the complexity of its chart, each lens has a curve at a different aperture and focal length. Therefore, readers often feel at a loss. Unlike for resolution indicators, it is simple and clear. At a glance, we can see that the center resolution of a lens is xx line/mm, and the edge is xx line/mm. However, resolution data cannot be compared under different experimental conditions, and the discrete rate of the measured results is large. As a result, there have been "UK data", "US public photography data", "German evaluation", "Qian Yuankai data" in China, and "Yu Qilin data, readers are dazzled. A certain shot has a remarkable performance in this data, ranking first, while in another data, the performance is average, and the evaluation is average, making buyers feel at a loss. Fortunately, the Swedish Hassu lab has been testing more than 400 35mm cameras in eight years with the use of MTF dedicated testing equipment and a full-time inspector, providing objective and impartial comments respectively, provides guidance data for users and manufacturers.

Description of the MTF Value

Description of the MTF value: A -- Version B -- imaging record

The MTF value (modulus Transfer Function) is a value that comprehensively evaluates the sharpness, contrast, and resolution of the lens. For a plane black (white) object, its line frequency is 0. At this time, the contrast can be fully reflected by any of the simplest lenses. That is, the MTF value is equal to 1. For pure black and pure white lines (contrast: 100%), as the frequency of the line increases, the contrast between the lens performance is reduced accordingly (contrast less than 100% ). When the line frequency reaches a very high value (for example, 1000 line pairs/millimeters), any lens can only record them as a gray one. At this time, the MTF value of the lens is close to 0. Therefore, the MTF value is a value between 0 and 1. The larger the value (the closer it is to 1), the stronger the ability of the lens to restore the truth. For example, in the case of a 10-wire/millimeter line frequency on a 35mm negative film, the MTF value of a high-quality lens is about 95%, while that of a amateur lens is about 90%, in this way, the differences between ordinary 5-inch films are almost invisible. For 40-wire-to-millimeter line frequencies, the maximum MTF value of high-quality lenses can reach more than 70%, while that of amateur lenses is only about 40%. When the negative film is enlarged to a 24-inch screen, the differences in the details of the subject are fully reflected. For high-resolution and low-intensity lenses, although the eyebrows of a black-haired white-Skin Girl (with a large contrast) can be clearly argued, for a northern German (gray-white skin) or India (black hair and brown skin) girls, because of the lack of contrast, their eyebrows can only be blurred. Take the gray-haired girl's distribution before the white background as an example (assuming the contrast is 0.45): The contrast is still 0.45 x 70% = 0.315 after passing through a high-quality camera, the contrast is reduced to 0.45 x 40% = 0.18 after the amateur camera. We know that when the gray text is printed on white paper, the contrast between the two is less than 0.2, it is difficult for readers to identify, not to mention the contrast of only 0.18 at this time.

How to interpret the lens's MTF Value

The figure shows Carl Zeiss T * 28 ~ 85/3 ~ The four lenses are located in the focal lengths of 28mm, 50mm and 85mm mm respectively, and the MTF value line chart is displayed when the maximum aperture and aperture values are 8. Each graph has three pairs of curves. The top one is the MTF value corresponding to the 10-wire pair/millimeter. The middle one is equal to the 20-wire pair/millimeter, and the lower one is equal to the 40-wire pair/millimeter. The line in each curve represents the MTF value (radial) from the center of the drawing to the surrounding direction of radiation, and the dotted line represents the MTF value (tangent) of the tangent direction of the circle around the center of the drawing ). Both are equally important. The abscissa represents the distance from the measured point to the image center. The 0mm points represent the center position of the image, and the 21mm points represent the four corners of the film. The ordinate value is the MTF value of the point.

Let's look at the two pictures on the left. The focal length is 28mm. When the optical circle value is f3.3 and the line frequency is 10-wire/millimeter, the radial MTF value at the center of the film is 0.96, and the tangent MTF value is also 0.96. At the center distance of 15mm, the radial MTF value is 0.91, and the tangent MTF value is 0.84. When the online frequency is 20-wire/millimeter, the radial MTF value at the center of the film is 0.87, and the tangent MTF value is 0.87, the radial MTF value is 0.76, and the tangent MTF value is 0.62. When the online frequency is 40-wire/millimeter, the radial MTF value at the center of the film is 0.69, and the tangent MTF value is 0.69, the radial MTF value is 0.47, and the tangent MTF value is only 0.34.
When the aperture value is f8, the diameter of each line frequency and the tangent curve data are significantly improved, which means that when the aperture is f8, the Optical Imaging of this lens is much better than that when the aperture value is f3.3.
In the same way, you can read the MTF value of the lens under the two aperture values of 50mm and 85mm mm.
The outside focal imaging quality of the lens can also be seen in the MTF Curve. The closer the radial and tangent curves are, the softer the focal outside imaging of the lens. It can be seen that when the lens is at the focal length of 28mm, the focal outside imaging of the lens is much worse than that of the focal length of 85mm.