using oil immersion: how, why and tips
Next practical many of you will use the immersion oil lens (i.e. the x100 lens) for the first time.... This can be tricky, so before you try this in your next lab, I though it would be a good idea to post you some helpful tips on this procedure.... First of all, why are you bothering with immersion oil? Immersion oil has the same diffractive index as glass. This means that the light travelling through your specimen won't diffract when it passes between the slide and the x100 lens because it is passing through a drop of oil rather than the air. As a result more light is collected by the lens and you have a clearer image...... image taken from : http://en.wikipedia.org/wiki/File:Immersionsvorteil.svg In this diagram, the yellow region represents oil. So you can see that on the left, when the light rays (black arrows) pass from the sample to the lens, they do not bend at all. On the other hand, if you look at the right side of the image, you can see that when t...