What is the difference between a flat field achromatic objective and a regular achromatic objective?

The objective lens is the most critical component of an optical microscope, assembled from a series of lenses, responsible for converging the light emitted by the sample and imaging it through the eyepiece. It is the first transmission element through which light passes from the sample to the phase plane, closest to the object.

An achromatic objective is a common objective in the laboratory. The correction of spherical aberration by an achromatic objective is limited to the range of yellow and green light, and only red and green light are corrected for chromatic aberration. When using an achromatic objective, there is still residual chromatic aberration and image domain curvature. Compared to achromatic objective lenses, flat field objective lenses provide good correction for image domain curvature. The best objective is a flat field apochromatic objective, and when using a flat field objective, the image edges will be clearer!

A flat field achromatic objective has a larger clear range compared to an achromatic objective. For 100 × In terms of objective lenses, this difference is particularly significant, to the extent that most users are using 100 × When using an achromatic objective lens, it is necessary to frequently move the stage for observation, which is more obvious for users who need to take photos or take photos. The surrounding area of each photo is blurry. forty × The clear range of the achromatic objective lens is not large enough, but it is not as good as 100 × So serious. forty × The following is much better, 4 × It's almost impossible to see much difference. Recommendation 100 × The objective is matched as a flat field achromatic objective. Considering the economy, 40 × The following objective lenses do not need to be replaced.