15 public questions tagged with this topic.
FOV = FN / objective mag. FN 18 mm /40 = 0.45 mm. Eyepiece mag does not affect FOV diameter formula, but affects total mag (600x). High WF eyepieces increase FN.
Ref: NCBI Bookshelf, Molecular Biology of Cell: Resolving power, numerical aperture, and Abbe limit.
Parfocality should maintain focus, but slight refocus with fine knob needed. Also check oil, dirty lens, wrong coverslip (#1.5 required).
Ref: Nikon MicroscopyU, Microscope Condenser: Height adjustment and illumination quality.
Compound microscope produces real inverted image. If slide moves right, image moves left.
Ref: NCERT Biology, Class XI, Chapter 8: Objective properties and working distance concept.
Working distance decreases with higher magnification. 40x has ~0.6mm WD vs 4x has ~18mm.
Ref: NCERT Biology Laboratory Manual, Class XI, Steps for focusing and observation.
Higher magnification shows smaller area. FOV at 40x is ~4x smaller than at 10x. Formula: FOV = field number / objective mag.
Ref: NCERT Biology Laboratory Manual, Class XI, Microscope handling and safety precautions.
10×100 = 1000x is maximum with light microscope. Beyond this empty magnification without gain in resolution.
Ref: NCERT Biology, Class XI, Practical guidelines for slide observation and field of view.
Total magnification = ocular magnification × objective magnification = 10×40 = 400x.
Ref: NCERT Biology Laboratory Manual, Class XI, Calculation of total magnification.
Modern microscopes use built-in LED or halogen with intensity control. Old models used mirror reflecting daylight.
Ref: NCERT Biology, Class XI, Chapter 8: Illumination system in microscope.
Iris diaphragm controls aperture, affecting contrast, depth of field and resolution. Closing too much causes diffraction.
Ref: NCERT Biology Laboratory Manual, Class XI, Illumination control using iris diaphragm.
Condenser gathers light from illuminator and focuses it into cone on specimen. Abbe condenser NA ~1.25.
Ref: Nikon MicroscopyU, Fundamentals of Light Microscopy: Condenser function and Kohler illumination.
40x is high power objective. Requires careful focus, small working distance, and fine adjustment only.
Ref: NCERT Biology, Class XI, Chapter 8: Compound microscope optical system.
Standard eyepiece is 10x (wide-field WF10x). Some have 15x. Total magnification = eyepiece x objective.
Ref: NCERT Biology, Class XI, Chapter 8: Optical parts of microscope, eyepiece role.
