I have what i suppose is a Classic Japanese Microscope 70's maybe not sure.
Looking for a decent light source for it if anyone has suggestions?
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Posted 23 March 2019 - 03:26 AM
Microscope illumination is a science in itself.
The easiest and cheapest way to achieve usable illumination is by using a regular frosted or opal household light bulb and setting lllumination up as "critical" or "Nelson" illumination, in which the image of the light source is formed in the microscopic image.
It goes as follows:
- put he microscope on a table and place the bulb at a distance of some 30 cm from the (flat side of) the microscope mirror
- place a slide on the microscope and focus the image more or less at low magnification
- "search" the light source by looking into the microscope while rotating and tilting the mirror
- Once found, hold a tooth pick, a match or something like that on the surfase of the bulb and try to obtain the sharpest possible image of the tooth pick in the microscopic FOV by raising/lowering the substage condenser
- "Control aperture": remove the eyepiece, look in the microscope tube and open/close the condenser diaphragm untill it's onely barely visible as a
small circle at the edges of the image.
Repeat the last step every time you change objectives.
A focusable centering telescope is a great help for this. These are readably availlable and usualy not very expensive. They look like this:
Pros and cons of this method
Pros: inexpensive, readily availlable, not difficult, easy to achieve even illumination, even at low magnfications, which is often a problem when using other methods
Cons: light level in the microscopic image, contrast, resolution are all rather low.
I'll write something on "real microscope illuminators", such as these, and on how to use them tomorrow:
On the right is a "LUX FNI", made by Reichert in Austria, on the left a Zeiss "Leuchte 15" (= Illuminator 15), both 1950's - 1960's era.
Both uses a low voltage incandescent bulb. (Both bulbs are difficult to get these days).
Posted 30 March 2019 - 11:09 PM
Thanks for the detailed reply,
yes I remember some of that, I haven't used this in a long time, If I remember I had a small 240V bulb in a tin can with an opening in it. Similar to the idea you said,
Never seen a telescope for a microscope ? Interesting !
I was playing around using my OWZ 178MC camera with the microscope works but magnifies the image a great deal compared to a normal eyepiece x5 or x10 . Small sensor I guess.
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