Distinguish between $v$ and $\nu$

Question

I'm writing a manuscript (100 page) and I used many times the symbols $v$ and $\nu$ in mathematical mode. For example my equations have the form:

$\frac{u+v}{\nu}=0$ and the pdf gives the following: 

Unfortunately, after compiling, the two symbols $v$ and $\nu$ are very similar and it is very difficult to distinguish them.

Please can you help me to overcome this problem knowing that I can't change the symbol $v$ in 100 pages

Answer 1

Judging from the image you probably have

\usepackage{mathptmx}

in your document.

Replace it with

\usepackage{newtxtext}
\usepackage[varvw]{newtxmath}

and the output of

\[
\frac{u+v}{\nu}
\]

will be, with no other change to your document,

Answer 2

Using Computer Modern for v and \nu.

\usepackage{newtxtext,newtxmath}
\DeclareSymbolFont{CMletters}{OML}{cmm}{m}{it}
\DeclareMathSymbol{\nu}{\mathord}{CMletters}{23}
\DeclareMathSymbol{v}{\mathord}{CMletters}{`v}

Answer 3

I got the same problem, but since I did not want to make any changes (I wasnt sure if the proposed solutions would change anything in a finalised document, such as line-breaks, any slight changes of spacing, etc.), i preferred the following solution that solves the problem by adding a single line ("AtBeginDocument..."):

\documentclass{book}

\usepackage{amsmath}
\usepackage{txfonts}

\AtBeginDocument{\mathcode`v=\varv}

\begin{document}

A `v' in math: $v$

A `nu' in math: $\nu$

\end{document}

Answer 4

This code follows along the lines of Gavin R. Putland's comment on Syrtis Major's answer, but it makes the Computer Modern \nu a bit thicker, so it fits in better with a Times font. It also has a bold version, patterned on this answer. (To explain the '027 of the fifth line, see this answer.)

\documentclass{article}
\usepackage{newtxtext,newtxmath}
\DeclareSymbolFont{CMMforNu}{OML}{cmm}{m}{it}
\SetSymbolFont{CMMforNu}{bold}{OML}{cmm}{b}{it}
\DeclareMathSymbol{\nuCM}{\mathord}{CMMforNu}{'027}
\usepackage[outline]{contour}
\def\nu{\mathord{\contourlength{0.0043em}\contour{black}{$\nuCM$}}}
\begin{document}
\[ \frac{u+v}{\nuCM \nu \boldmath\nu} \]
\end{document}

I got the idea of using the contour package in this way from this answer and the comment on it by diabonas. As an alternative to using the contour package for making the symbol darker, the pdfrender package could be used, as in this answer and this answer.

If you want the v to look as in egreg's answer, change the second line of my code to

\usepackage{newtxtext}\usepackage[varvw]{newtxmath}

and the result is

For discussions of non-Computer Modern versions of \nu and how to distinguish them from v, see the answers to this question.