Mikrotron eosens TS3, User Manual, Page: 94 / 120

TS3 User Manual
11S-3000M
page 85
Figure 9-5: Navitar 50mm f/95 Lens
10. Adjust the illumination and / or the exposure setting t o get the right exposure, avoiding
saturation. ( K eep the lens set at its largest aperture. It is important to use the shallowest depth
of focus possible.)
11.
Look at the witness mark on the lens. It should be pointing o 5’/1.5m. If it is not, continue
on with the adjustment.
12.
Set the lens to the 5’/1.5m witness mark.
13. If the focus got noticeably w orse, go on with the adjustment.
14. Loosen the two C-Mount Lock screws (see “Figure 1-3: TS3 Top View” and “Figure 1-3: TS3
Top View”). The C-Mount is threaded onto the TS3 Opti on al Block. Loosening the screws enable
turning the C-Mount for adjustment.
15.
Turn the C-mount adapter a short distance one direction, then back t o where it was, then the
other direction. Y ou will quickly learn which way to turn it to get be tt er results.
Note: The C-mount has 3/32 threads on it. It also has a scalloped pa tt ern on its edge comprising 36
indentations. R otating the mou n t the distance of one of these indentations is equi v alent to adjusting
the back focus distance a .022mm or a little less than .001 ” It is a good goal to adjust the back focus
to within a couple of these indentations, or less than .05mm / .002 ”
16. When you are sati f fied th a t the back focus is adjusted as well as you can get it, tig h ten the
two adjustment screws and reconfirm the f ocus.
Setting f or Infinity
If you will be using the TS3 exclusively for close by objects and are sati s fied th a t the back focus is
correct, you may skip this part. If, however, you will be using the camera for activities wh er e it will b e
imaging far away objects, you will w ant to confirm th a t it can focus at infinit .
To do this you will need to find a place
where you can set the camera up that
has a good view of objects at various
distances.
17. Check the location of the reference
mark made on the lens in #7, above.
18. Look at the last witness mark
on the lens before infinit y . Find an
object in your field of vi e w that is
approximately the distance indicated
by that last witness mark. For example
on the Navitar 50mm f/.95 lens, the
last witness mark before infinity is
10m. So you would find an object
approximately 10m away and focus on
it.
19. Is the lens now set close to the
10m witness mark? Continue findin
targets farther and farther away to get
a feel for how far the lens can focus to.
If the best focus for very far objects is at or a ti n y bit before the infinity s top, the lens is OK. If you
find that the best focus for the farthest objects is not close to the infinity s top, or you find th a t you
just cannot focus on far away objects, repeat #14 through #16 above.