Notes:
Where a range of maximum diameter is given in the table this reflects the fact that there is
a prominent rim or ledge to the body of the eyepiece so the larger of the two
measurements refers to the diameter of the ledge. The presence of a prominent ledge can
make it difficult to mount in the standard eyepiece clamp of the AF51.
The ‘Exit lens diameter’ is the clear aperture of the final lens in the eyepiece nearest the
user’s eye (this is sometimes called the ‘ocular lens’ but that term also refers to the
eyepiece as a whole in many contexts so I just use ‘exit lens’ – not to be confused with
‘exit pupil’ of the optical system).
‘Diam. OK’ means you can clamp this eyepiece in the standard AF51 eyepiece clamp
without a custom or optional adaptor.
‘Eye point OK’ means the standard AF51 eyepiece adaptor can hold the eyepiece at the
correct distance for optimum imaging of the field of view.
‘Full circle field’ described whether the image includes the whole round field of view. In the
two most wide field eyepieces tested this is not the case because the width of the
eyepiece field is wider than the width of the camera field of view.
All the eyepieces were tested on a PUMA microscope with some also tested on other
microscopes (a Zeiss Standard, an Olympus BH2 BHS and a Leica DMLS). Field of view
measurements were about the same regardless of which microscope was used (but eye
point measure differed – only the eye point measure from the PUMA microscope is
shown).
The number of threads stated in the comments refers to how high the eyepiece clamp lock
nut needed to be to get optimal imaging and refers to the number of threads showing from
from the base of the threaded part of the clamp to the lock nut (see figure 3.11).
‘Field % pixels’ and ‘Field MP’ refer to how much of the full 5 MP image field is occupied
by the microscope FOV in the image. The range of useable pixels between these
eyepieces is quite large (see figure 5.5). Some of the cheapest eyepieces, while useable
for direct vision, give such small coverage in the AF51 camera field of view that the
available pixels encompassed by the eyepiece field of view is very small (less than 1 MP).
OptArc AF51 Camera Page 55 of 99 User Guide v1.02
