Modifies a noun

• refractor: There is a little bit of color shift but the filter looks like a good addition to an achromatic refractor.

• lens: With achromatic parfocal lenses, the Swift is of quality comparable to the better student microscopes.

• telescope: An achromatic telescope of Bradley, one of the earliest examples, is here.

• objective: Some of the finest photographs I've ever seen of diatoms were taken with achromatic objectives with a plate camera in 1904.

• combination: E. Microscopy using achromatic combinations of lenses with matched focal lengths.

• condenser: Achromatic condensers are better, but not so commonly supplied with microscopes owing to their intrinsically higher costs.

Noun used with modifier

• power: But it was difficult to make small high power achromatic lenses.