Please tell me how to use the road test card?

The resolution card (resolution card) is a standard sample that can provide auxiliary tests such as vertical resolution and horizontal resolution of actual shooting.

The resolution test uses the international standard ISO12233 resolution card for testing, and adopts a unified shooting angle and shooting environment.

The resolution calculation uses HYRes software, which is divided into two parts: vertical resolution and horizontal resolution.

The evaluation of digital cameras is different from other products. Unlike laptops, DIY, etc., there are a lot of software to test objective data, which can explain everything from the data. In addition to certain objective data, evaluation of the quality of digital cameras also requires a combination of actual use and sample shooting. Therefore, our evaluation is based on the principle of objective data and combined with rational analysis by experienced evaluators in order to obtain the most objective evaluation results.

The ISO12233 standard resolution test chart complies with the 12233 standard "Photography - Electrophotographic Screen - Measurement Methods". In this active area of ??1 It has the characteristics of almost most resolution cards.

Many people are curious, since there is already an MTF method to judge the resolution of cameras and lenses, why do we need to develop different resolution test methods? This is a very good question. The MTF theory has been tested and proven correct! But the key lies in the sample pictures taken! Since the MTF test chart composed solely of lines is essentially subject to the limits of the output device, when DSLRs with up to ten million pixels are launched, such as Nikon D2X or Canon EOS 1Ds MKII, their shooting resolution has surpassed traditional film performance (in the past, the traditional 135mm film was defined as approximately one thousand pixels). In other words, when the advancement of equipment begins to exceed the limits of USAF1951 and ISO12233, the test has no relative significance.

Therefore, MTF has developed for decades, and the same reproduced sample images have also continued to evolve, meeting the actual needs of current general shooting conditions. We look at the ISO Camera Resolution Chart ISO12233 as a good example. The resolution chart of this period has been adjusted to imitate the actual scene. Not only the lines have been made with hyperbolic approximation, but the format is no longer exclusively straight and horizontal lines. Please note the five points marked with red numbers on the top. This figure is specially used for visual inspection of resolution performance:

Vertical Res (Vertical Res)---can visually inspect the resolution of vertical images by the lens.

Contrast Indicator--used to display the contrast status under different spatial frequencies.

Diagonal Res—a 45-degree tilted diagonal resolution bar.

Center Focusing Area--two concentric circles of different frequencies to assist in focusing.

Horizontal Res—the horizontal image resolution of the lens can be visually measured.

The new version of Digital CINE Camera Resolution Chart adds Sector Star Target to test the astigmatism effect.

The WG18 chart not only satisfies direct visual inspection to evaluate the resolution effect (some lines are as thin as 0.1mm, almost the same thickness as a human hair), but can also be used to calculate the resolution at different positions with the assistance of computer software. SFR value, original size 20 cm x 35.6 cm, can also be purchased on domestic professional optical shopping websites, such as: www.tilo.cn.

SFR The new standard of American measurement

New term SFR! Spatial frequency response (SFR) is mainly used to measure the impact on a single image as the spatial frequency of lines increases. In short, SFR is a streamlined version of MFT. Because measuring MFT requires obtaining expensive sinusoidal samples and converting a large amount of data. Therefore, PIMA developed this lower-cost SFR as an alternative. Basically, SFR only needs a two-tone black and white diagonal line (as shown in the left picture below) to convert a resolution evaluation chart that is approximately equivalent to the value of MFT.

As the times progress, ISO12233 must also change to keep up with the ever-changing equipment performance. The latest version of the resolution test chart (pictured above) has been launched. This digital CINE Camera Resolution Chart is also based on the ISO12233 standard.

In addition to maintaining the original test standards, the scale of the CINE chart has also been expanded in response to the future development of digital imaging equipment, and it also includes higher-resolution interpretation elements (for DSLRs with more than 10 million pixels). The CINE chart display reaches 60 cm x 144cm. .