Why do you need to first use the scanning objective lens? – It allows to see a larger section of your sample not only in width but also in depth – It does not require oil, so it is easier to use – it is less expensive than the others – it is further from the slide, so you won’t break the objective
The Correct Answer and Explanation is:
The correct answer is: It is further from the slide, so you won’t break the objective.
Explanation:
The scanning objective lens (usually 4x magnification) is typically the first lens you use when observing a sample under a compound microscope for several reasons. The primary reason is that it is further from the slide compared to higher magnification lenses, which reduces the risk of accidentally damaging the lens or the slide itself. At the lower magnification, it is easier to locate your sample, and you have a larger field of view, which makes it much simpler to find the area of interest on your specimen.
Using the scanning lens first allows you to “roughly” locate your specimen and position it in the center of the viewing area before switching to higher magnification objectives (e.g., 10x, 40x, or 100x). This is a crucial step because the higher magnifications have smaller fields of view, and it can be challenging to locate specific structures at those levels without first scanning the sample with the lower magnification.
Additionally, the scanning objective lens does not require oil (unlike the oil immersion objective), making it easier to use and more practical for initial observations. It’s also generally less expensive compared to higher magnification objectives. The design of the scanning lens ensures it is far enough from the slide that it won’t come into contact with the specimen, making it safer during the initial scanning phase.
Overall, the scanning objective is ideal for starting your observation because it offers ease of use, safety, and a wider field of view, helping you navigate the slide before zooming in for detailed analysis with higher magnifications.
