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

Add Comment

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.

Add Comment

  • 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.

Add Comment

  • 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.

Add Comment

  • The front tube, thread on the inner side.

  • The rear tube, thread on the outer side.

Add Comment

  • 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.

Add Comment

Conclusion

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

Terrance

Member since: 11/17/2009

3,854 Reputation

5 Guides authored

0 Comments

Add Comment

View Statistics:

Past 24 Hours: 0

Past 7 Days: 2

Past 30 Days: 34

All Time: 220