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ABOUT TRIPOD, HEAD AND VIBRATION

MARCH 2005

market. But the consistent performance is not an easy character to be obtained. Some may show good holding performance in fresh condition but the performance degrades very quickly.

result possible. If there is wind, all these differ- ences cannot be seen. The effect of wind will dominate in image blurring.

If you look into the details of the graphs, you will notice that there are big difference between Markins ball heads and others. This is due to some micro slip29 at the contact area of the ball and its counterpart. However the Markins ball heads held the test bar firmly in any moment.

Long Teleport Lens with MLU and Self-Timer Test

VIBRATION AMPLITUDE [um]

40

20

0

  • -

    20

  • -

    40

7.45um

When you really want to record the image with high resolution, you should do MLU and use self- timer. Next experiments were taken using with 205FCC Hasselblad camera, 250mm f4 lens at 1/8 second after mirror was locked up.

Again I started with 3 way head. This time 3 way head performs good. There are less energy in- duced by mirror-up shock and it has very large holding contact surface compared with typical ball head. That means, if other situations are ideal and if the mass center of lens and camera is well balanced at the geometric center, it can perform really okay. I’ll list 2 test results for each head set.

VIBRATION AMPLITUDE [um]

40

20

0

  • -

    20

  • -

    40

0.3

0.6

0.7

0.8 0.9 TIME IN SECOND

[Hakuba #1]

7.93um

0.4

0.5 0.6 0.7 TIME IN SECOND

[Hakuba #2]

1.0

0.8

1.1

0.9

Again, these results were obtained in very ideal indoor conditions. These are probably the best

29 In the result of Arca Swiss B1, it looks better in dam- pening. But closer look of the 3rd peak reveals that it slipped a little downside. The vibration was damped by consuming a frictional energy. The following vibra- tion decreased by frictional damping. It worked well this time, but if the impulse happens when the lens is in its lowest position, it will increase the amplitude. It de- pends on luck. However, Markins M20 and M10 with- stand the mirror down shock and continue to vibrate in upward direction. This means that they do not slip.

VIBRATION AMPLITUDE [um]

40

20

0

  • -

    20

  • -

    40

0.1

8.5um

0.2

0.3 0.4 0.5 TIME IN SECOND

[Markins M20 #1]

0.6

0.7

VIBRATION AMPLITUDE [um]

VIBRATION AMPLITUDE [um]

VIBRATION AMPLITUDE [um]

PAGE 8 OF 15

40

20

0

  • -

    20

8.3um

  • -

    40

0.3

0.4

0.5 0.6 TIME IN SECOND

[Markins M20 #2]

40

20

8.85um

0

  • -

    20

  • -

    40

0.3

0.4

0.5 0.6 0.7 TIME IN SECOND

[FOBA #1]

40

20

8.75um

0

  • -

    20

  • -

    40

0.6

0.7

0.8 0.9 TIME IN SECOND

[FOBA #2]

0.7

1.0

0.8

0.8

1.1

0.9

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