If you are looking for an optical comparator thats real value for money then Carmar-Technologies has the answer. 

Carmar-Technologies Ph 3020  heavy duty bench 14" dia screen optical comparator with horizontal beam axis and brilliant optics for easy shadow or surface viewing. Rugged all steel construction ensures high accuracy and its  large workstage  area provides easy positioning of components between lamphouse and lens to be measured. Classified as general toolmakers or final inspection  projector,  the large 400 x 150mm workstage  has x 200mm (H) z 100mm z (V)  travel, complete with a x 10 lens and multi -functional geometric readout with edge sensing option ensures real value for money.

If you require  a larger capacity projector the Carmar Ph 4025 may be the answer, featuring a screen size of 400mm diameter, heavy duty workstage of 450 x 200mm size  and travel of 250 x 150mm. The unit is supplied with a x 10 lens as standard and the geometric analyser makes this the ideal comparator for final inspection of larger  parts. 

A selection of lenses and accessories from x 10 to x 200 mag., vees, centers, vices and screen templates are available, all at keen prices.

Heavy duty 30" optical comparator with very large workstage capacity.

This S-T comparator  sets the industry standard for large capacity with accuracy. Two versions are available, S-T2600 and S-T 5600  which offer options on lens holders and optical format.

Workstage travel is 200 x 500mm travel plus 600mm option, a choice of digital readout systems from Quadra-chek is available with 1um resolution.

Models  available are ST-2600 with reverse or S-T 5600 with erect images, both have options of  CNC driver control for programmed inspection.

Heavy duty 24" horizontal beam optical comparator with very large workstage capacity.  Powerful illumination makes viewing surface or profiles easy on the eye.

Features include: gothic arch bearings, superior optics than most competitors, 3 lens turret, 1um  stepper motor stage drive and 200 x 300mm stage travel.