Measuring collimation error on Olympus CH2
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yippyfingers
- Posts: 10
- Joined: Mon Dec 18, 2023 6:34 am
Measuring collimation error on Olympus CH2
I adjusted the collimation on my CH2 until I ran out of adjustment. Using a 10X Olympus eyepiece with crosshairs and horizontal 0-100 scale, I put the crosshair on a small target using the left eyepiece tube. Moving the eyepiece to the right tube, I found that the crosshair was roughly 0.00004" from the target, or 0.001 mm, using the 40X objective. I believe that this is pretty close, but is it good enough? Am I measuring collimation correctly?
Re: Measuring collimation error on Olympus CH2
Hmmm would be interested in the proper way how to do this calibration as well: @PeteM, @Apo, @Saro: please chime in!
Re: Measuring collimation error on Olympus CH2
For practical purposes, binocular collimation of heads is in the eyes of the beholder. If you can view specimens for long periods of time without eyestrain, I'd say you're OK. Close is often good enough, though some individuals seem more sensitive than others.
As far as methods, there are fancy optical setups - once with reflective collimators and now with laser ones - but the methods of putting a target on the stage and adjusting things so the target is in the same place are often good enough for compound microscope heads, where one of the eye tubes has been knocked loose. If a prism has come loose inside, it's often possible to see telltale signs of where it was once glued and return it to that position. Slight tweaking of the eye tubes might then be needed.
Collimation of an entire scope is a bit more complicated. You want every element at the center of its optical axis from the lamp, its collimating and field lenses, the condenser, stage, turret and objectives, and then the head. Most user manuals provide instructions on getting the lamp and condenser in alignment. Repair manuals may go through the entire gamut.
It can get more complicated with stereo microscopes since there are so many more degrees of freedom and lenses/prisms to get out of whack, especially if there is a zoom involved. In those cases, OEM instructions and sometimes tools are wanted.
As far as methods, there are fancy optical setups - once with reflective collimators and now with laser ones - but the methods of putting a target on the stage and adjusting things so the target is in the same place are often good enough for compound microscope heads, where one of the eye tubes has been knocked loose. If a prism has come loose inside, it's often possible to see telltale signs of where it was once glued and return it to that position. Slight tweaking of the eye tubes might then be needed.
Collimation of an entire scope is a bit more complicated. You want every element at the center of its optical axis from the lamp, its collimating and field lenses, the condenser, stage, turret and objectives, and then the head. Most user manuals provide instructions on getting the lamp and condenser in alignment. Repair manuals may go through the entire gamut.
It can get more complicated with stereo microscopes since there are so many more degrees of freedom and lenses/prisms to get out of whack, especially if there is a zoom involved. In those cases, OEM instructions and sometimes tools are wanted.