Text with specified FontSize looks smaller than expected

Question

The simplest way to see what the post's title is trying to convey is to evaluate:

{"-0.5",
  Text[Style["-0.5", FontFamily -> $DefaultFont[[1]],
           FontSize -> $DefaultFont[[2]]]]}

On my Windows 7 laptop, at least, the first 0.5 looks larger than the second one. (The first one looks "right" to me somehow).

My understanding is that $DefaultFont specifies the default output font, so I'm puzzled by the obvious difference (illustrated by this example) between text using the default output font, and text using a font explicitly set to match $DefaultFont (i.e., the first and second elements in the output of the evaluation above).

Clearly my understanding is wrong somewhere, but I can't figure it out.

Ultimately, I'm looking for a reliable way to specify the font size and font family of text elements in Graphics generated by Plot, etc.

FWIW, I'm using version 9.0.1.0.

Answer 1

As István Zachar noted in his comment, $DefaultFont is deprecated. Setting the BaseStyle option is the way to go. For example. I frequently set the following options.

SetOptions[Graphics, BaseStyle -> {FontFamily -> "Helvetica", Bold}];
SetOptions[Plot, BaseStyle -> {FontFamily -> "Helvetica", Bold}];

Note, I don't monkey with font size. I prefer to let Mathematica vary font size as it sees fit.

Now let's look at what difference setting BaseStyle makes in the case of a simple plot.

SetOptions[Plot, BaseStyle -> {}];
Plot[Sin[x], {x, 0, 2 Pi}, PlotLabel -> "It's all a plot (pun intended)"]

SetOptions[Plot, BaseStyle -> {FontFamily -> "Helvetica", Bold}];
Plot[Sin[x], {x, 0, 2 Pi}, PlotLabel -> "It's all a plot (pun intended)"]

Note that BaseStyle affects all the text in the plot, even the tick labels.