Which microscope objective is commonly referred to as the high dry objective?

• A. High dry
• B. Low power
• C. Oil immersion
• D. Plan apochromat

Answer: (A)

A dry high-magnification objective is designed for viewing specimens without immersion oil while providing more detail than the low-power lens. It’s the lens type labeled for high magnification under dry conditions, typically around 40x (sometimes 43x) with a moderate numerical aperture suitable for routine brightfield work on prepared slides.

Oil immersion is a separate category that uses immersion oil between the coverslip and the objective to boost numerical aperture and resolution; it’s not considered dry. Plan apochromat refers to a corrected optical design and can be used with or without oil, but the name itself doesn’t indicate dry high-magnification usage.

So the option labeled High dry is the one that corresponds to the high dry objective.