Distortion and chromatic aberration test chart
Generally, the function of rotationally symmetric optical systems is to form an image that is geometrically similar to the object except for in some particular systems, such as fish-eye lenses and eyepieces, where this condition is deliberately not maintained. Ideally, this function is accomplished according to the geometry of perspective projection. Departures from the ideal image geometry are called distortions.*
The TE251 test pattern is designed for the image quality measurement of distortion and chromatic aberration in digital imaging, e.g., with DSLR, compact camera or a mobile phone. It is based on the ISO 17850 Photography — Digital cameras — Geometric distortion (GD) measurements standard, which was released in 2015, as well as on other standards such as IEC 62676-5 and IEEE P1858 CPIQ.
The chart contains black crosses on a white background and is available as a reflective and transparent test target.
The image quality analysis of this special grid delivers the LGD (local or line geometric distortion), the TV distortion, the CA (chromatic aberration) and the LCA (longitudinal chromatic aberration).
The TE251 is supported by the iQ-Analyzer-X image evaluation software. The software will provide an assessment of TV distortion, LDG, LCA and CA.
*Read technote for more information on What is "lens geometric distortion".
| Type | selectable |
| Format | selectable |
| Aspect ratio | 16:9 |
Chart sizes
The test charts are available in the sizes listed below. Please note that some charts cannot be manufactured in all sizes due to technical reasons. Please do not hesitate to ask for additional information.
During production, specific regions of test charts are measured to qualify the production process or to create individual reference data accompanying a test chart additionally. Measured regions can be color or gray tones.
The measurement devices are calibrated regularly and proven before use. You can find further information in our reference data accuracy sheet.
Reflective
| Picture size w x h [mm] | Chart size w x h x d [mm] (+/- 2 mm)* | ||
|---|---|---|---|
| 4:3 | 16:9 | ||
| A1066 | 800 x 600 | - | 1245 x 835 x 3.2 |
| A1066 (TE42*) | 900 x 675 | - | 1245 x 835 x 3.2 |
| A1066 | - | 1066 x 600 | 1400 x 835 x 3.2 |
| A1066 (TE42*) | - | 1200 x 675 | 1400 x 835 x 3.2 |
| A540 | 540 x 405 | 540 x 303.75 | 600 x 500 x 3.2 |
| A460 | 460 x 345 | 460 x 258.75 | 600 x 500 x 3.2 |
| A444 | - | 444.4 x 250 | 600 x 500 x 3.2 |
| A360 | 360 x 270 | 360 x 202.5 | 500 x 400 x 3.2 |
| K360 | - | 360 x 202.5 | 390 x 271 x 2.1 |
| A280 | 280 x 210 | 280 x 157.5 | 365 x 305 x 3.2 |
| K280 | 280 x 210 | 280 x 157.5 | 334 x 271 x 2.1 |
| P280 | May vary in size with the chart layout | 334 x 271 x 2.1 | |
| K180 | - | 180 x 101 | 204 x 164 x 2.1 |
| K160 | 160 x 120 | - | 204 x 164 x 2.1 |
A charts (size 280/360/460) are mounted on aluminium plates.
A charts (size 1066) are mounted on aluminum composite panels (aluminum dibond).
K charts mounted on black polystyrene plates are only available in combination with the test chart folders
P charts are mounted on black polystyrene plates.
*Sizes are for all variations of the TE42 chart series, including TE42 V2, TE42-LL, TE42-LL Timing
Transparent
| Picture size w x h [mm] | Chart size w x h x d [mm] (+/- 2 mm)* | ||
|---|---|---|---|
| 4:3 | 16:9 | ||
| D280 | 280 x 210 | 280 x 157.5 | 360 x 280 x 4.6 |
| D240 | 240 x 180 | 240 x 135 | 320 x 290 x 4.6 |
| D240S | 240 x 180 | 240 x 135 | 360 x 280 x 4.6 |
| D205 | 205 x 153 | 205 x 115.3 | 253 x 202 x 3.5 |
| D120 | 120 x 90 | 120 x 67.5 | 155 x 135 x 4.0 |
| D60 | 60 x 60 | - | 100 x 100 x 4.5 |
| D35 | 32 x 24 | - | 50 x 50 x 3-4 |
D60 charts are intended to be used with the Vega light source and are constructed with aluminum, PLA plates, and a magnet mount. .
D35 charts are either between glass plates or mounted in slide frames (glassless).
There are exceptions regarding mounting and size for special charts.
Suitable transparent charts for the following illuminators
| D280 / D240S | D240 | D205 | |
|---|---|---|---|
| Spherical transparency illuminator LE6/LE7 Lightbox illuminator LG3 Sony Pattern Box |
DNP standard viewer | Porta Pattern spherical transparency illuminator |
|
| With adapter | Spherical transparency illuminator LE6/LE7 Lightbox illuminator LG3 |
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*Chart sizes may vary by +/- 2 mm as they are handmade in house.