Proximity Series


InfiniTube™ FM-Series

Video/Machine Vision Microscopes

A Complete OEM Microscope Now Fits in The Palm of Your Hand!*

  • FM-50, FM-75, FM-100 and FM-200 for FOUR Magnification/Size Choices
  • C-mount (CS-mount w/5mm optional spacer)
  • Covers 2/3-in. and Smaller Sensors
  • Internal Focusing (FM-100 & FM-200)
  • Focuses New Low-cost PL-Series Objectives
  • Adapts to Most Major-brand Infinity-corrected Objectives Including Achrovid™, Mitutoyo and Nikon
  • Optional Mini-coaxial Illuminator w/Matched Collectors
  • Optional DL Doubler Multiplies all Magnifications by 2x
  • Low Price/Uncompromised Quality
InfiniTube FM-100 with DL Tube & PL-Objective

InfiniTube FM Series

Size: 1 MB   Updated: 08/31/2021
• Optical Data
• Magnification Tables
• Instruction Manual
Size: 144 KB   Updated: 12/01/2022
• Price List

*The FM-Series are more “highly-evolved” InfiniStix. We took the InfiniStix concept and brought that to near-perfection!

InfiniTube FM-Series

The InfiniTube FM-Series are miniature multi-element infinity-corrected microscopes. They are are actually more complex optics than the observation tubes of most compound research microscopes. In addition, two models (FM-100 and FM-200) incorporate internal focusing, allowing adjustment from a fixed position.

All infinity-corrected microscopes require a tube lens system focal length (f) of a set standard. Infinity’s own objectives, Mitutoyo and Nikon are all based on f = 200mm. When a shorter focal length tube lens is used, a proportional reduction in magnification results. Our FM-100 consequently has half the magnification of our FM-200, etc.

InfiniTube FM-Series is one of Infinity’s three compact micro lens offerings:

InfiniTube FM Series
InfiniStix™
InfiniFlex™

You are now looking at InfiniTube FM-Series

In order to cover a full range of magnifications with objectives rated for f = 200mm tube lens systems, we have produced a series of FM InfiniTube Main Bodies: FM-50, FM-75, FM-100 and FM-200. All cover up to 2/3-in. video sensors.

FM-50 and FM-75—when equipped with PL-series objectives—are effectively higher-apertured versions of our well-known InfiniStix™ line. Although the PL-Series are ultimately based on f = 200mm, to make it easy to compute matters, their PRIMARY magnification is based on the FM-50 = 1x factor. FM-75 provides a 1.5 factor; FM-100 a 2x factor and FM-200 a 4x factor (then equal to f = 200mm—or true microscope objective equivalency).

InfiniTube FM-Series Main Bodies are highly adaptable. For example, since FM-100 provides half the magnification of regular infinity-corrected microscope objectives based on f = 200mm, supplementing it with a 2x DL Doubler Tube results in a smaller, more compact 200mm system than FM-200—an advantage where space limitations are encountered. However, the FM-200 achieves this equivalent optical tube length without the need for extra cost options in a slightly larger assembly.

FM-100 and FM-200 have built-in internal focusing to make adjustment possible from fixed positions. FM-50 and FM-75 are fixed-focus. All FM-Series InfiniTubes have 30mm outer diameters, allowing the Small Clamp to be used (singly or multiply) to secure them to fixtures.

Adapters are available for other brands of standard infinity-corrected microscope objectives (M26 for Achrovid™ and Mitutoyo, M25 for Nikon and RMS for Olympus). Since Olympus objectives are based on f = 180mm, magnification increases slightly (1.11x with FM-200, for example).

In addition, Infinity Photo-Optical has developed two new accessories for the FM InfiniTubes: The PL-Series objectives and the Mini Coaxial Illuminator. The PL-Series objectives offer extreme compactness, optical quality on a par with much larger, bulkier microscope objectives and extraordinarily long working distances. You won’t believe how they compare to traditional micro objectives at a fraction of their cost!

Recently, three new PL-Series Objectives have been developed for very long distance observations, designated FD (Far Distant),  They provide working distances of 195mm, 295mm and 390mm. They are primarily designed for use with the FM-100 and FM-200.

The Mini Coaxial Illuminator (MCI)—perhaps the smallest of its kind— can be used with the PL-Series directly, and with adapters, for most major-brand microscope objectives.  Rotatable side collector lenses (high and low-power versions) can be fitted with an accessory polarizer filter, and a receptacle on the MCI accepts a second analyzer filter, permitting variable polarization.

InfiniTube FM-200 with MCI and a PL-Series Objective (Total length: 147mm)
PL-Series Objectives
PL/FD-Series Objectives

Complete FM-Series

InfiniTube-FM-50
InfiniTube-FM-75
InfiniTube-FM-100
InfiniTube-FM-200