at what objective magnifications is it not ok to use the course focus adjustment?

Use the coarse focus to raise the stage all the way up until it blocks. The objective at the highest position, the 4x objective should of course not touch the slide. Close the condenser and looking through the eyepiece lower the stage using the coarse focus until you see a clear image.

Full Answer

What does the magnification of the objective lenses mean?

Remember that the objective lenses are parfocal, which means that once the low magnification lenses (4X or 10X) are in focus, the higher magnification lenses (40X and 100X) are also in focus. Only fine adjustment is needed to obtain a sharp image.

When should I use the coarse focus adjustment?

The coarse focus adjustment should only be used when you are viewing a specimen with the 4x or 10x objective lens. Keeping lab safety in mind, why should you not put broken glass in the trash can?

Why can't I focus the high power objectives with the coarse focus?

If you focus the high power objectives with the coarse focus knob, then you risk slamming the objective into the slide, risking the damage of both. Some high power objectives are spring-loaded, with a front-part that retracts when touched by the slide. This is a protective mechanism. Reason 2: danger of loss of focus

What is the fine focus adjustment knob on a microscope?

The fine adjustment knob is the smaller of the smaller of the two knobs and is located further away from the arm of the microscope. Most coarse and fine adjustment knobs are built with coaxial control in line with one another so you can easily switch from using the coarse focus adjustment knob to using the fine focus adjustment knob.

At which magnification should you never use the coarse focus adjustment?

DO NOT USE THE COARSE ADJUSTMENT KNOB WHEN FOCUSING UNDER THE 40X OBJECTIVE! ONLY USE THE FINE ADJUSTMENT KNOB!

Can you use coarse focus with the 40X objective?

the coarse focus knobs? A: Only use the fine focus with the 40X and 100X objectives; can use the coarse focus with the 4X and 10X objectives.

Why do you only use the fine focus adjustment knob when using the 10X 40X or 100X objectives?

When using 10x and 40x objectives, use ONLY the fine focus knob so that you don't scratch a lens or break a slide. Always carry your microscope with one hand under the base and one hand on the arm. Some microscopes may have a mirror as the light source.

For which objective can you use the coarse adjustment to focus the specimen?

7. Focusing knobs: located on both sides of the microscope. The larger, inner coarse adjustment knob moves the stage up and down much faster and farther than the smaller, outer fine adjustment knob. The coarse adjustment knob is used ONLY with the low power (4X, 10X) objectives.

Why is immersion oil not used with the high power 40x objective?

Dragging the 40x lens through the oil will damage the lens! The immersion oil has the same refractive index as glass, so you may go back to low power (again, not 40x) and still see your specimen.

Why is oil never used with the high power 40x objective?

Never go back to the 10x or 40x objectives after you have applied oil to the specimen since oil can ruin the lower power objectives. [The 4x objective can be used because it is high enough to be above the oil.] 7.

Why is it important not to use the coarse focus knob with the 40x objective?

The coarse focus knob is never used when the 40X objective is in position above the specimen. If the coarse focus is used with the 40X objective, the objective could ram the slide causing damage to it or even worse, damage to a the objective lens itself.

Why is the coarse adjustment knob only used with the 4X objective lens?

The gearing mechanism of the adjustment produces a large vertical movement of the stage with only a partial revolution of the knob. Because of this, the coarse adjustment should only be used with low power (4X and 10X objectives) and never with the high power lenses (40X and 100X).

Which part of the microscope should never be touched when 40x objective lens is in position identify it by clicking on it?

And anything higher than that because adjustment knob is not generally moved and if you move it then the image gets blood or distorted and that way you cannot view the image properly. So yes the court's assessment of in the microscope should not be touched when it's in the 40 X. Objective lens.

Which part of the microscope should not be adjusted when using the 100x objective?

TO MOVE INTO OIL IMMERSION, 100x MAGNIFICATION Do NOT MOVE the focus knobs or the stage knobs. Swing the 40X objective (high dry) out of the way. Place a single drop of immersion oil on the slide right over where the light is coming through the stage, and rotate the 100X obective (oil immersion) into place.

Why is oil immersion used in 1000x lens?

Placing a drop of oil with the same refractive index as glass between the cover slip and objective lens eliminates two refractive surfaces, so that magnifications of 1000x or greater can be achieved while still preserving good resolution.

When using high power objective you should not adjust the?

CAUTION: NEVER, EVER, use the coarse adjustment knob with the high power objective. This could break the lens. Multiply the power of the ocular lens, by the power of the objective lens. 2.