*
While I was replacing the camera I noted a huge difference in the
evenness of the lighting if I tilted the camera as it was inserted into the fitting. I was almost able to
have even surface texture over the entire 1936x1216 maximum frame size. The images show the extent of etalon tuning error on image variation of brightness.My tilting plate won't allow so much tilt with the standard thumbscrews. The whole thing soon locks up. It would require one set of holes be opened out to allow tilting clearance and then longer tension screws fitted.
When square-on, half, of the
image is too bright. The other half is fine. The real question is why the field of view is so
asymmetrically badly lit and heavily biased to one side? It must be the etalon which is causing this.
This can be checked by removing the rubber band and outer shell. Then
rocking the etalon with a close fitting rod in a suitable hole in the
inner, tuning arc.I rotated the tuning band to find the most even surface texture. Then flexed the entire filter stack. To find that an even, full screen was almost attainable.
The PST etalon sweet spot is a well known characteristic. I can produce a dark ring or various other shapes of shade in the field of view simply by turning the etalon tuning band. By reversing the tuning band back and forth only slightly the dark ring shifts bodily right across the image. So there must be unwanted slop in the etalon adjustment. Or in the etalon's support system.
*
No comments:
Post a Comment