Field and Complementing Lenses

Field and Complementing Lenses for Telescope

At present, the field and complementing lenses used in the eyepiece of telescope as well as filter lens mostly use optical resin lens. Because of high transmittance, good plasticity and low price of PMMA and PC, etc. they are most appropriately used for the eyepiece of telescope system. Since 1980s of last century our company has made mass production of field lenses and complementing lenses which are adopted by manufacturers throughout the country and sold to Hong Kong and abroad. Now more than 40 varieties of field and complementing lenses are supplied for market. The data of field and complementing lenses is shown in following table for user selection. If there in no need for you, our company can design and manufacture them according to user’s supplied drawing and sample.

Data Sheet of Field and Complementing Lenses for Telescope

Cautions for use of optical plastic field lens

1 The optical plastic field lens produced by our company adopts imported "PMMA" material. The hardness of this material is lower than optical glass, easy bruising, therefore, should not be more polished.

2 The ash spot and fuzz on the surface of optical plastic lens are easily cleaned and dried by blowing them off with compressed air. Usually the production and assembly lines are equipped with compressed air blowpipe.

3 In case of fingerprints on the surface of optical plastic lens, don’t clean it with alcohol, ether and mixing cleaner, use Freon (F11 or F113) instead. F11 and F113 Freon are colorless, odorless, nontoxic and a good cleaner, usually used in ultrasonic cleaning parts.

4 In Freon-free cleaning, the breathe-out method can be used to wipe out fingerprint and ash spot gently with cotton ball. The fingerprints can be wiped out with ether, but ether can be used to rub the fingerprints only with one or two cotton balls, no more rubbing.

5 The static electricity has been eliminated from optical plastic filed lenses during production but a tiny electrostatic charge will be generated after stored for some time. In mass production it is necessary to buy “ionic-wind X eliminator” , which is developed by our company for use in the production and assembly lines so that the ash spot and fuzz can be easily removed, thus making the optical plastic lenses more clean.

6 If necessary, the optical plastic lens can be plated with hard coat. After plated with hard coat, the optical plastic lens is not changed in transmittance and its hardness is very high, thus easily plated with various optical coats and cleaned with alcohol, ether, mixed and other chemical solvents.