ligo-ex ligo-ds
  Richardson Lab Experimental Log  Not logged in ELOG logo
Message ID: 9     Entry time: Tue Jul 26 14:10:35 2022
Author: Cassidy 
Type: Update 
Category: Cameras 
Subject: Optical Post Replacement and Realignment 
Today I replaced the 3" optical post that the camera rests on with a 2" optical post in order for the screen to correctly fill out the camera's FOV. The 3" post is now in the glass optics cabinet next to the FLIR camera configuration box, wrapped in the protective materials from the 2" post for safekeeping.

There were no issues with the physical replacement of the post, except that the fork clamp on the post needs to be on one of the perpendicular, not diagonal, axes in order to be secure. I chose the front axis (towards the screen) as before in order to easily access the alignment knobs.

To align, I followed the same process as last time except for a more purposeful original rough alignment. For alignment purposes, the visual camera was used. For the first rough alignment, I pulled the camera as far back as possible on the x axis (with the z axis roughly centered), then moved the entire stage setup back until I could just see both the top and bottom edge of the screen. Then, I set the z-axis to an extreme in order to use the edge of the screen to align the rotational and y-axis pieces for the fine alignment.

For the fine alignment, starting with the z and x axis at extremes, I began by aligning the rotational axis. To do this, I used the gaps between the top of the screen and the camera window on the far left and right of the image. When these gaps were equal I knew the rotation was adequately set. Then, I set the y-axis so that the pattern was centered. If the gaps were no longer even, I redid the rotation alignment and ditto with the y axis until both were set. This resulted in a rotation of about two degrees and a y axis at just under 3.5.

To set the z and x axis, I centered the z-axis using the top and bottom of the screen, which should both be visible if the rough alignment was done correctly. Then, I adjusted the x axis by pushing it forward until the top and bottom of the screen were just out of the frame. As with the rotational and y-axis, I iteratively fine tuned the x and z axis until both the image was centered in the z axis and only the screen was in view. This resulted in a z-axis value of just over 5.5 and an x axis value of nearly 1.75.

Pictures are included of all alignment knobs and the new post/stage setup!

Attachment 1: YAxisAlignment.png  11.846 MB  | Hide | Hide all | Show all
YAxisAlignment.png
Attachment 2: XRotZAlignment.png  12.294 MB  | Hide | Hide all | Show all
XRotZAlignment.png
Attachment 3: NewOpticalPost.png  13.665 MB  | Show | Hide all | Show all
ELOG V3.1.3-7933898