Introduction

Partial / tactical teardown, for cleaning and quick repair.

    • Face lens down, (front on table)

    • Remove 3 screws on the lens mount

    • Remove lens mount

    • Pull / push trpod mount towards back of the lens, and remove it. Be patient, it is very precisely assembled.

    • Loosen tripod ring, till it can rotate.

    • Remove tripod ring. Be aware, the is a 90 degree stepping steel ball inside.

    • photos TBD

  1. Do NOT remove 3 focus scale calibration screws. I actually did that when attempting disassembly. And luckily, I also marked the original position before that.
    • Do NOT remove 3 focus scale calibration screws. I actually did that when attempting disassembly. And luckily, I also marked the original position before that.

    • I tried to remove the front element group first. But the thread is some how locked and impossible to turn using my current tooling. So I gave up, and most cleaning does not need to remove front group.

    • Remove focus ring rubber. Take your time, it's a huge piece and might be glued.

    • Remove 2 focus stop screws. Your's might be in different holes. Also you may like to calibrate that. There 3 holes at the infinity end, and 2 at the close-up (8m / 25 ft) end.

    • READ THIS FIRST! In the following step, rotate slowly, and apply gentle force pulling front and rear apart, and mark the position of separate.

    • Rotate the rear half of the lens, towards close-up direction (CW as looking downwards), pass 8m/25 feet mark and continue, while applying gentle force pulling rear part up, until they separate, mark the point.

    • When assemble them back, attach from this angle/point.

    • The front tube, thread on the inner side.

    • The rear tube, thread on the outer side.

    • This is just a partial tear down. This lens is extremely well made, and very very precise.

    • Until this point, this is a reasonable "maintenance teardown". And you can do most mirror and lens cleaning and grease replace.

    • Putting them back from the point/angle you marked in previous step, the focus scale does not need a calibration.

Conclusion

To reassemble your device, follow these instructions in reverse order.

Terrance

Member since: 11/17/2009

4,132 Reputation

5 Guides authored

One Comment

I am looking for more understanding of this breakdown. I have questions about the fragility of the components and how to clean the interior of the front glass of mold spores. Additionally i would love to understand how to calibrate its focus. Can you advise?

zack - Reply

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