Image focus (focus adjustment) is maintained at all focal lengths (zoom-in) and constant distance from object by means of back focal distance adjustment. If necessary optimize by alternating with optical focus adjustment.Ģ、With unchanged optical focus adjustment and shortest focal length adjust the red and blue pick-up tube until optimum focus is achieved. With shortest focal length and divergent focus adjust the pick-up tube in W-channel until optimum focus is achieved. The target should print onto an 8.5x11 sheet of paper. Ive made available a similar target in Adobe Illustrator (CS6) and in PDF format. I believe those charts are expensive and/or copyrighted. Set optical focus at greatest focal length. Find many great new & used options and get the best deals for Sticker 3 7/8in Sticker Siemens Star Test Pattern Chart Focus Crosshair DSLR Sr at the best. In the video clip, the author refers to a 'Siemens Star' chart. The following image is a small crop (409 x 280 px) from the center area of the 6000×4000 px frame. It is taken from a shot with the Auto Revuenon 1.4/50 MC shot at f/2.8. SVG format only please, not PDF nor any of the raster formats. Preferably with solid bars, not sinusoidal. With the aid of a low transmission filter and by means of low level lighting make sure that the camera is not over modulated with the aperture in the open position.Ī) Optical focus: Adjust focus of zoom lens at greatest focal length.ī) Back focal distance (lens): Adjust focus at shortest focal length by regulating lens mechanically with adjustment screw and optimize alternatively with a).Ĭ) Back focal distance (pick-up tubes): If focus varies from channel to channel between greatest and shortest focal length, the individual pick-up tubes must be adjusted mechanically in the optical axis.ġ、Select white channel. 0 Comments Trying to evaluate the results, I found myself again BEING THE JUDGE (so: no objectivity as well). Need a link to a downloadable Siemens Star Chart in SVG format But not the one in the Wikipedia article, it has too few spokes, looking for 144 cycles or 72 at a pinch. It shows a 36 sector Siemens star on a white background. The YE0120 test chart is designed for the adjustment of camera lenses and checking back focal distance.
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