Bresser Science ETD-201 8-50x Trinocular Zoom Stereo Microscope

The Science ETD-201 is a trinocular zoom stereo microscope with 105 mm of working distance, for assembly and inspection in electronics and precision mechanics, for dissection in a biology or forensic lab, and for schools that want a stereo microscope students can't outgrow. A stereo microscope shows the object in 3D, the right way up, so hands and tools under the lens behave as expected.

The 0.8x to 5x zoom objective, a ratio of 6.25, with the WF10x eyepieces gives a continuous 8x to 50x. The eyepieces are in 30 mm tubes and can be swapped for other powers; eye relief is 21 mm, so glasses can stay on, eye spacing runs from 55 to 75 mm, and each eyepiece has dioptre adjustment. The head turns through 360 degrees, with the eyepiece tubes inclined at 45 degrees and a separate camera tube on top for a C-mount camera or a MikroCam.

LEDs light the object from above and below, together or separately, with a dimmer, and the top light's angle adjusts and locks, so a solder joint can be lit from the side to show its profile. The base is extra wide with a tall column, so objects up to 100 mm high fit under the lens, and the 105 mm working distance leaves room for a soldering iron or forceps. Focus is a coarse knob; there's no fine focus on this model, and no mechanical stage.

The box contains the zoom head, the stand, two WF10x eyepieces, a glass plate, a black and white plastic plate, a dust cover and the manual. Our guide to microscope types explains when a stereo microscope is the right choice over a compound one. The Advance ICD below it zooms 1x to 4x with a shorter working distance, the ETD-301 above it adds fine focus and a 7x to 63x range, and our stereo microscopes are grouped together.