TC Filter kit

Telecentric lens filter and plug-in filter holder Download flyer

Light filtering is a typical need in machine vision measurement applications. For instance, you may need to avoid possible interactions between your LED illuminator and other light sources in an industrial environment.

Moreover, sun light is very frequently causing errors in imaging systems due to unexpected reflections from the surface of the parts being measured.

In these cases, a band-pass or long-pass filter that matches the emission wavelength of the illuminator is usually integrated in front of the objective: this way, only the light coming from the illuminator is collected while the rest of the spectrum is cut out.

Furthermore, many machine vision applications require monochromatic illumination in order to enhance or suppress particular object features: under these conditions, only the features with a certain color are imaged and can be measured.

Part number Description Matching products Diameter Weight
(mm) (g)
TCFILTER Filter mount for telecentric lenses TC 12 yyy, TC 23 yyy (1), TC2M yyy (2), TC4M yyy(1) - 10
COBP470D17.5 Blue (470 nm) bandpass filter -B LED sources 17.5 5
COBP525D17.5 Green (525 nm) Bandpass filter -G LED sources 17.5 5
COBP635D17.5 Red (635 nm) Bandpass filter -R LED sources 17.5 5
COBP850D17.5 IR (850 nm) Bandpass filter - 17.5 5
COBP880D17.5 IR (880 nm) Bandpass filter - 17.5 5
COLP920D17.5 IR (920 nm) LongPass filter - 17.5 5
COPR032D17.5 Linear polarizer - 17.5 5


  1. Except TC23004, TC23007, TC23009, TC23012
  2. C-mount versions only

Ordering information

When ordering a filter for a C-mount telecentric lens insert both the filter mount (P/N: TCFILTER) and the optical filter in your order.

For example: if you need a green filter to be mounted onto TC23036 telecentric lens, order both the following items:
· TCFILTER - Filter mount for telecentric lenses
· COBP525D17.5 - Green (525 nm) Bandpass filter. 17.5 mm diameter

Technical documents

Data table XLS
Product user guide PDF
COBP series PDF

Press & marketing content

Accessories brochure PDF
Opto Engineering 2014 catalog PDF

Can't find the information you need? We strive to provide clear and concise documentation of all our products. If you need further details, or maybe you need it in a specific format/context, feel free to contact us, we'll be happy to satisfy your requests.

Putting a filter in front of a telecentric lens can be very inconvenient when the size of the lens is very big. The filter should be as large as the front element of the lens, thus becoming very expensive.

To overcome size and cost issues, Opto Engineering designed a smart filter adaptor that can be easily plugged into the rear part of the lenses. This simple and cost-effective accessory is compatible with all TC 12 yyy and TC 23 yyy bi-telecentric lenses and with the C-mount versions of TC4M and TC2M series bi-telecentric lenses.

The bi-telecentricity of the Opto Engineering lenses makes this solution very efficient, since the rays remain parallel when passing through the filter. This allows for the optical bandpass to be maintained across the entire image surface.

Since inserting the filter will increase the back focal length of the lens, spacers (included in the TC lens package) must be added to the C-mount in order to set the lens back to its nominal working distance; the overall thickness of the spacers is usually equal to 1/3 of the filter thickness.

The supported filter diameter is 17.50 mm and the maximum recommended filter thickness is 4.00 mm.

Opto Engineering also offers a selection of standard filters fitting Telecentric lenses and LTCL series collimated illuminators.