AmScope SM-3 stereo microscope

Field widths, millimeters
Through the occularsThrough the Leica MC170 camera
Zoom knob position0.
0.5x objective759476.2
Normal 1x objective324.7213.0
2x objective14.52.1101.7

This is a trinocular zoom stereo scope, which can take the same c-mount cameras that many of the other microscopes use. The normal 1x objective has a nominal magnification variable from 0.7 to 4.5x , a range of about 6.4 .

The basic parts are labeled here. The magnification ranges can extended by upwards or downwards by factors of about 2 with the use of add-on objective lenses (see below) that screw into the bottom of the fixed objective lens, labeled here.

There are two illuminators, the oblique illuminator, with two lamps (shown), and a ring illuminator that mounts on the objective (see below). Here’s the oblique illuminator manual.

Commonly the microscope focus knob (vertical range 5 cm) isn’t enough to accommodate either your sample or the add-on objectives. In that case, hold the microscope body, loosen the height adjustment knob, and raise or lower the microscope body, as necessary. Don’t forget to tighten the height adjustment knob. Also, putting platforms, like books or blocks of wood under your sample can also be a help.

There are three ways to focus the microscope. For normal viewing, use microscope focus knob (vertical range of 5 cm), and the ocular focus rings. For the camera, use the microscope focus knob, and the camera focus ring. Sometimes the camera and ocular views won’t be in focus at the same time (parfocal). In that case: 1) set the camera focus ring in the middle of its range, 2) focus for the camera using the microscope focus knob, 3) focus the oculars using the ocular focus rings.

The other side of the same microscope. Here, the coaxial ring illuminator is shown mounted on the fixed objective, using a threaded adapter. To take pictures, the binocular photo mirror has to be slid out. Slide it in for binocular viewing. The camera uses the image from the left side.

These are the extra objectives, which decrease (0.5x) or increase (2x) the effective magnification of the fixed objective. They thread into the fixed objective, but be sure the ring illuminator adapter is removed, because it doesn’t have any threads. You can still use the ring illuminator with these add-on objectives, because the ring illuminator will clamp directly onto them just fine.

This shows the coaxial ring illuminator adapter (left), the lamp itself (center), and the power supply (right). The adapter is only needed for the fixed objective. Be careful threading it on, it’s made of plastic.