{"id":1497,"date":"2010-05-26T15:46:50","date_gmt":"2010-05-26T22:46:50","guid":{"rendered":"http:\/\/wkoopmans.ca\/notebook\/?p=1497"},"modified":"2011-02-22T15:57:53","modified_gmt":"2011-02-22T23:57:53","slug":"pentax-k-7-sensor-shift-composition-adjust","status":"publish","type":"post","link":"https:\/\/wkoopmans.ca\/notebook\/?p=1497","title":{"rendered":"Pentax K-7 Sensor shift (Composition adjust)"},"content":{"rendered":"

One of the features of the Pentax K-7 is that you are able to move the sensor by small amounts along the focal plane.\u00a0 The effect of this is to adjust the position of the image formed by the lens on the sensor.\u00a0 This differs slightly from moving the camera and therefore the lens and sensor.\u00a0 Figure 1<\/em> shows a lens and sensor positioned so that light from point (A)<\/em> goes through the center of the lens and reaches the sensor at it’s center (A1)<\/em>. In this scenario point (B)<\/em> is obscured by point (A)<\/em> and none of it’s reflected light reaches the lens.\u00a0 Now if we were to move only the sensor using the composition adjustment feature of the K-7 as in Figure 2<\/em> The image formed by the lens is relocated on the sensor but because the lens has not moved the relationship of the elements in the scene remain unchanged and point (B)<\/em> remains obscured.\u00a0 Now if we were to reposition the entire camera as in figure 3<\/em> the new position of the lens allows some reflected light from point (B) <\/em>to reach the sensor.\u00a0 So even though (A1)<\/em> reaches the senor at the same point in figure 2&3<\/em> the image formed differs.<\/p>\n

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A simple way of demonstrating this effect is to close one eye and hold a piece of paper edge on in front of the other eye.\u00a0 What you will see is a very thin slice of paper, now swap which eye is open and closed while not moving the paper.\u00a0 Now you will see a partial side view of the paper, just as if you repositioned a camera.\u00a0 Of course the distance between your eyes should be greater than the amount the sensor is able to shift so the effect is exaggerated.<\/p>\n

Here is the effect demonstrated in practice.<\/p>\n

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This is the neutral position for the scene<\/strong><\/p>\n

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Sensor shifted left<\/strong><\/p>\n

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Sensor Shifted Right<\/strong><\/p>\n

Notice how even though the position of the element within the frame changes the relationship does not.\u00a0 The ball appears to just visually touch the right hand edge of the blocks in all three.<\/p>\n

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Camera shifted right<\/strong><\/p>\n

Notice how in this instance the right side of the block is now revealed.<\/p>\n

So the composition adjust of the Pentax K-7 allows you to modify the framing of a scene while preserving the relationship of the elements of the scene.\u00a0 It also allows rotation of the sensor to further aid in composition.\u00a0 This feature is found under “Rec. Menu 2”<\/p>\n","protected":false},"excerpt":{"rendered":"

One of the features of the Pentax K-7 is that you are able to move the sensor by small amounts along the focal plane.\u00a0 The effect of this is to adjust the position of the image formed by the lens on the sensor.\u00a0 This differs slightly from moving the camera and therefore the lens and […]<\/p>\n","protected":false},"author":1,"featured_media":0,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[36,6],"tags":[19,22,52,364],"class_list":["post-1497","post","type-post","status-publish","format-standard","hentry","category-cameras","category-photography","tag-camera","tag-composition","tag-pentax","tag-photography"],"_links":{"self":[{"href":"https:\/\/wkoopmans.ca\/notebook\/index.php?rest_route=\/wp\/v2\/posts\/1497"}],"collection":[{"href":"https:\/\/wkoopmans.ca\/notebook\/index.php?rest_route=\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/wkoopmans.ca\/notebook\/index.php?rest_route=\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/wkoopmans.ca\/notebook\/index.php?rest_route=\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/wkoopmans.ca\/notebook\/index.php?rest_route=%2Fwp%2Fv2%2Fcomments&post=1497"}],"version-history":[{"count":20,"href":"https:\/\/wkoopmans.ca\/notebook\/index.php?rest_route=\/wp\/v2\/posts\/1497\/revisions"}],"predecessor-version":[{"id":2422,"href":"https:\/\/wkoopmans.ca\/notebook\/index.php?rest_route=\/wp\/v2\/posts\/1497\/revisions\/2422"}],"wp:attachment":[{"href":"https:\/\/wkoopmans.ca\/notebook\/index.php?rest_route=%2Fwp%2Fv2%2Fmedia&parent=1497"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/wkoopmans.ca\/notebook\/index.php?rest_route=%2Fwp%2Fv2%2Fcategories&post=1497"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/wkoopmans.ca\/notebook\/index.php?rest_route=%2Fwp%2Fv2%2Ftags&post=1497"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}