Camera Motion Pixel Blur on 70-200 IS II.

Started Oct 8, 2015 | Discussions thread
OP technoid Senior Member • Posts: 2,244
Re: Camera Motion Pixel Blur on 70-200 IS II.

Here's the results of comparing mirror lockup v shutter only motion impact on MTF at 55 l/mm on a Manfrotto tripod with the center post extended 1 ft.

Shutter and mirror retraction induced motion reduction in MTF v angular direction

Notice the difference between the 5DSR(solid lines) and 1Ds(dashed lines). The larger dashed and solid lines are with mirror lockup. The motion induced by the mirror is significant resulting in a reduction in MTF mostly from vertical motion. On both the 5DSR and 1DsIII the MTF is reduced by about 20% even with mirror lock and about 45% without.

At 1/1000th sec. (not shown) the differences are about halved and doubled at 1/250th.

It gets much worse as the shutter speed drops down to about 1/15th then improves. At over 1 sec. exposure the motion induced reduction in MTF becomes once again negligible but environmental factors including even light breezes can reduce the MTF at very slow speeds.

Raw data was processed with Matlab with the RGB Bayer pixels normalized. Lens, Canon 70-200 ISM II at 200mm w/o stabilization.

This was the target which has 10 repeats of a pattern of 7 evenly spaced sine waves radiating from the target center to allow measuring MTF along multiple axes.

7 equal amplitude sine wave repeating 10 times from center

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