[Orgmode] configure latex fragments preview

[Nicolas Goaziou]

Hello,

This is some minor annoyance, but I would like to find a solution for it
anyway.

The preview image of a latex fragment produced by C-c C-x C-l is so
small that I sometimes find it hard to read.

In order to solve that situation, I modified org-format-latex-header so
that the template for the preview starts with
\documentclass[17pt]{extarticle}.

Though, I find it not quite satisfying as there is little control on
that size (I would like it to be a bit less than 17pt). Thus my question
(eventually) : is it possible to play with dvipng options like scale or
dpi directly, without modifying org.el ?

And if it doesn't exist, could a variable be introduced to fine-tune it ?

As a last note, I think there is a Latex only way to solve all of this,
but I wouldn't like to depends on too much latex packages or tricks.

Regards,

-- 
Nicolas Goaziou