Alignment/Imaging
The testers longitudinal axis needs to be aligned to the mirrors optical axis, and the
film plane needs to be perpendicular to that axis. The time consuming initial alignment's
need be done only once. From then on, a laser pointer is used to quickly align the tester.
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| Initial Alignment |
| Longitudinal Axis to the Mirrors Optical Axis: |
- Center dot the mirror.
- Mount the mask with the center hole over the center dot, also making sure
the holes are level.
- Observe the center slit with a 10 mm eyepiece. Rotate the tester (camera tripod
works well) horizontally and vertically so as to keep the center slit image fixed
with respect to the upper mat cutter blade while moving the tester on the longitudinal
axis - Figure 15.
- In order to avoid doing this again, aim an attached laser pointer at the center of
the mirror. Lock the laser pointer down. Mark where the returning beam strikes an
attached card - Figure 16.
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| Source Plane Perpendicular to the Optical Axis: |
- Remove the mask, making sure not to move the mirror or the longitudinal axis of the tester.
- Attach a plastic mirror to the Source Plane - Figure 18. Direct
a laser pointer through the hole of the plastic mirror to the center of the test mirror. Rotate the
Source Plane until the third bounce strikes the test mirror's vertical centerline -
Figure 17. Lock the Source Plane.
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| Imaging: |
- Center dot the mirror.
- Align the testers longitudinal axis to the mirrors optical axis:
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- Rotate the tester so that the attached laser hits the center of the mirror -
Figure 18.
- Rotate the test mirror until the returning beam hits the attached card where
previously marked - Figure 16.
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- Locate COC with the Foucault. It need not be precise - useful for the next step.
- Move the tester aft of COC by an amount where the image nearly fills the CCD.
After a bit, you will know exactly how far aft of COC you need to be.
Make sure the outer slit image is the edge zone image i.e., aft of COC the rays cross
the optical axis.
- Remove the KE.
- Mount the Mat Cutter Slit Assembly - Figure 13.
- Mount the mask with the center hole over the center dot, also making sure the holes are level. Also, make sure not to move the mirror.
- Attach the 10 mm eyepiece to the back of the Source Plane - Figure 18.
- Move the tester laterally to align the center-slit image to the edge of the upper mat cutter blade - Figure 18.
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- Manual mode.
- TIFF 3264x2448.
- ASA 1600.
- Exposure delay 12 seconds.
- Exposure 1/20 of a second.
- Remove the lens.
- Attach the E-300 to the Camera Spacer - Figure 13.
- Click - capturing the image.
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- In the dark mount the film to the image plane.
- Expose the film. An enlarger timer works well.
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