If the image does not appear as sharp as expected, a back focus adjustment is necessary. Before changing the back focus please note that the image photographed by the camera is generated on the focus screen inside the Mini35. This focus screen lowers the contrast of the image similar to the effect of a low contrast filter. This is desirable since it removes some of the electronic detail artifact typical in a DV image, even though at a quick glance the image may appear less sharp than the one recorded by the unfiltered original lens.
Test if the back focus is properly adjusted
Place the camera with the Mini35Digital image converter mounted with a 35mm lens, in front of a high quality test definition chart, such as the Putora 7A9 chart. The iris on the relay should be fully opened. The film lens should be focused by eye to the point of best resolution (highest number of circles visible on the Putora chart). Without changing anything else, close the iris of the relay a couple of stops. The resolution should not visibly increase. If it does, the back focus of the relay needs to be adjusted. Follow the steps below to adjust the relay back focus.
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