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