Answer: We need to start with the lowest magnification because it has a wider view of the specimen and we can find it more easily compared to the high power objective.

Why do you need to start with 4x in magnification on a microscope? The 4x objective lens has the lowest power and, therefore the highest field of view. As a result, it is easier to locate the specimen on the slide than if you start with a higher power objective.

When using a light microscope it’s important to start with the low power objective lens as the field of view will be wider, increasing the number of cells you are able to see. This makes it easier to find what you’re looking for.

When focusing on a slide, ALWAYS start with either the 4X or 10X objective. Once you have the object in focus, then switch to the next higher power objective.

The 4X lens is called the scanning or low power lens. It has the widest field of view, allowing you to look at large parts of the specimen, and the greatest depth of field.

Q: How much more area can you see with the 4x objective that with the 40x objective? i. A: When using the 4x objective one can see 2.32 more millimeters in diameter of the field of view.

Notice that all three threads are fairly well in focus, although the white thread on the bottom is a bit blurry. At low magnification, things appear bright, and it is easy to bring them into focus. Once you have explored the threads at 40X, switch to a higher powered objective.

Question 4a)Are all the three colored threads in focus at low power? Yes, all three colored threads were in focus.

The field of view is largest on the lowest power objective. When you switch to a higher power, the field of view closes in towards the center. You will see more of an object on low power.

With a large depth of field, all of the threads can be in focused at the same time. With a narrower depth of field, only one thread or a part of one thread can be focused at a time.

200 nm

The principal limitation of the light microscope is its resolving power. Using an objective of NA 1.4, and green light of wavelength 500 nm, the resolution limit is ∼0.2 μm. This value may be approximately halved, with some inconvenience, using ultraviolet radiation of shorter wavelengths.

To achieve the maximum (theoretical) resolution in a microscope system, each of the optical components should be of the highest NA available (taking into consideration the angular aperture). In addition, using a shorter wavelength of light to view the specimen will increase the resolution.