Video Transcript
Which of the following best defines
resolution? (A) Resolution is the number of
different structures that can be identified in an image. (B) Resolution is the minimum
distance apart that two objects can be in order for them to appear as separate
items. (C) Resolution is calculated as the
magnifying power of the objective lens divided by the magnifying power of the
eyepiece. Or (D) resolution is how many times
bigger the image is compared to the actual object.
You may recall that a microscope is
a piece of equipment used in biology to produce an image of an object that is too
small to be seen with the naked eye. To be able to draw useful
conclusions from microscope images, we need to know two important properties. These are magnification and
resolution.
Magnification is how many times
bigger the image is compared to the actual object. We can therefore eliminate answer
option (D) because it is not the correct definition for resolution.
Resolution, which is what this
question is asking us about, is the ability of a microscope to distinguish
detail. Let’s have a look at an
example. These images are both of the same
two cells. But they have been taken with
microscopes of different resolutions, as indicated in pink. In the image on the left, we cannot
make out the cells as two separate objects because they are closer together than the
resolution allows us to distinguish. In the image on the right, because
the resolution is better, even though the cells are the same distance apart, we are
able to distinguish them as two separate objects.
This is what resolution values tell
us. For example, with a resolution of
200 nanometers, we are unable to distinguish between objects that are closer
together than 200 nanometers. It’s important to be careful when
talking about resolution, as better resolution is often misleadingly referred to as
higher resolution, when in fact the value will actually be smaller.
We have therefore determined that
of the remaining answer options, the correct one is (B). Resolution is the minimum distance
apart that two objects can be in order for them to appear as separate items.
