AO 110 opportunity!

[cpsTN]

I have it for a while before I have to pay for it to make sure I want it, which I already know I do. He has several high-end scopes and he hasn't used this one in several years so I believe he was just trying to find a good home for it. I should be paying for it within the month.

[apochronaut]

Just wondering, Charles. Did your condenser end up having the auxiliary lens on it?

[apochronaut]

Does NA also relate to field of view ...

I don't believe so. Field of view is a function of the eyepieces.

For example if an eyepiece is marked 10x/20 it indicates a 10x magnification and a 20 mm field of view.
To see how that translates to the field of view available with each objective you divide 20 mm by the magnification of the objective and multiply by 1000

i.e. The field of view visible through the eyepiece for the following objectives would be:
100 magnification objective: 20/100 = 0.2 x 1000 = 200 µm
40 magnification objective: 20/40 = 0.5 x 1000 = 500 µm
20 magnification objective: 20/20 = 1 x 1000 = 1000 µm
10 magnification objective: 20/10 = 2 x 1000 = 2000 µm

This is irrespective of the NA of the objectives.

The scope has been shipped. Scheduled to be here Thursday the 26th.

Good news. Do post photos of it when you can.

This is a confusing formula 75RR. It is an easy way to calculate the actual f.o.v. from the apparent f.o.v. but it only works with 10X eyepieces. The field #( apparent f.o.v.) needs to be divided by the eyepiece magnification x 10. so with a 100x magnification objective being imaged with 15x eyepieces that have a 20mm apparent f.o.v. 20/(15x10)=1.33333x1000=133.33333mm

[75RR]

This is a confusing formula 75RR. It is an easy way to calculate the actual f.o.v. from the apparent f.o.v. but it only works with 10X eyepieces. The field #( apparent f.o.v.) needs to be divided by the eyepiece magnification x 10. so with a 100x magnification objective being imaged with 15x eyepieces that have a 20mm apparent f.o.v. 20/(15x10)=1.33333x1000=133.33333mm

I feel that you have muddied the waters a bit here.
I do not see the objective magnification in the formula. Are you not missing a step?

[75RR]

Note: Have gone back to the previous formula.

Eyepiece Field of View (fn) ÷ Objective Magnification (Mo) = actual field of view

My calculations based on the my stage micrometer were distorted by the DIC slide holders.

[apochronaut]

This is a confusing formula 75RR. It is an easy way to calculate the actual f.o.v. from the apparent f.o.v. but it only works with 10X eyepieces. The field #( apparent f.o.v.) needs to be divided by the eyepiece magnification x 10. so with a 100x magnification objective being imaged with 15x eyepieces that have a 20mm apparent f.o.v. 20/(15x10)=1.33333x1000=133.33333mm

I feel that you have muddied the waters a bit here.
I do not see the objective magnification in the formula. Are you not missing a step?

you use .1 of the objective magnification

[apochronaut]

Ok, figured out the problem. This is the formula:



The formula I posted previously was missing a step:
When the eyepiece is 10x then 10 ÷ 10 = 1 so the abbreviated formula works fine as the second step is unnecessary.

If however the eyepiece is 15x FN 20 for example, then 15 ÷ 10 = 1.5
So the actual field of view with a 100x objective would be:
(20/100) ÷ 1.5 = 1.3333 if we multiply that by 1000 to convert to microns we get 133µm
with a 40x objective we get:
(20/40) ÷ 1.5 = 0.3333 x 1000 = 333µm
with a 20x objective we get:
(20/20) ÷ 1.5 = 0.6667 x 1000 = 666µm
and so on ...
This formula works with whatever combination of Eyepiece Magnification and Field Number one has.

unfortunately, the formula you posted turned out to be very confusing for the person it was directed to.

[75RR]

unfortunately, the formula you posted turned out to be very confusing for the person it was directed to.

?
The person it was directed to has 10x eyepieces and was happy with the abbreviated formula, which works fine at that magnification.

Cool. That's a great formula to know, Thank You.

If he is confused perhaps it was due to your formula, which was missing the objective magnification.

[apochronaut]

No doubt. That which I posted to clarify your faulty example, an hour ago, confused someone yesterday.

[75RR]

Note: Have gone back to the previous formula.

Eyepiece Field of View (fn) ÷ Objective Magnification (Mo) = actual field of view

My calculations based on the my stage micrometer were distorted by the DIC slide holders.

[apochronaut]

could you repeat that, please. i didn't get it.

[75RR]

Note: Have gone back to the previous formula.

Eyepiece Field of View (fn) ÷ Objective Magnification (Mo) = actual field of view

My calculations based on the my stage micrometer were distorted by the DIC slide holders.