- bi ; bifocal, binocular
- nikon h.k.w. eyepiece : compensating eyepieces

- When it reached me, it was equipped with a pair of Olympus Bi WF10X, which, despite not being labeled C or K, appear to be compensating eyepieces, meaning they correct the lateral chromatic aberration of a conventional microscope. (Indeed, they work fine with Nikon Planachromat objectives in another microscope.) You can recognize a compensating eyepiece because the border of the field has an orange fringe. If objects in the field, near the edge, also have orange fringes, then compensating eyepieces aren't what you need. And if you use a compensating eyepiece in a telescope, the results can be truly amusing. - http://www.covingtoninnovations.com/michael/blog/0706/index.html

 

- focal length of microscope eyepiece = 250/x mag.

- carl zeiss e-pl 10x / 20 = 25mm 1set
- nikon 10x = 25mm 2set
- olympus 15x = 16.7mm 1ea
- nikon c-w 30x/7 = 8.3mm 1set
- union wfh 15x = 16.7mm 1set

	meade 90mm(fl=900)	viper 90mm (fl=1200)	mizar 80mm (fl=400)
8x = 31mm	28.8	38.4	12.7
10x = 25mm	36	48	16
15x = 16.7mm	54	72	24
20x = 22.5mm	72	96	32
30x = 8.3mm	109	144	48
uw 6	150	200	66.7
uw 20	45	60	20
lv 40	22.5	30	10

- lx 200 10inch f/10 sct
- x83.3 
- x100
- x150
- x111
- x300

- x417
- x125
- x62.5