Nginx – Turn off gzip for a location in Nginx

How can gzip be turned off for a particular location and all its sub-directories? My main site is at http://mydomain.com and I want to turn gzip off for both http://mydomain.com/foo and http://mydomain.com/foo/bar. gzip is turned on in nginx.conf.

I tried turning off gzip as shown below, but the Response Headers in Chrome's dev tools shows that Content-Encoding:gzip.

How should gzip/output buffering be disabled properly?

Attempt:

server {
    listen   80;
    server_name www.mydomain.com mydomain.com;
    access_log /var/log/nginx/access.log;
    error_log /var/log/nginx/error.log;
    root /var/www/mydomain/public;

    index index.php index.html;

    location / {
        gzip on;
        try_files $uri $uri/ /index.php?$args ;
    }

    location ~ \.php$ {
        fastcgi_pass unix:/var/run/php5-fpm.sock;
        fastcgi_index index.php;
        include fastcgi_params;
        fastcgi_read_timeout 300;
    }

    location /foo/ {
        gzip off;
        try_files $uri $uri/ /index.php?$args ;
    }

}

UPDATE

I turned off gzip in nginx.conf and tried using named locations. However gzip is now always off, and gzip on; in the location / block does not seem to turn gzip back on. Any ideas?

server {
    listen   80;
    server_name www.mydomain.com mydomain.com;
    access_log /var/log/nginx/access.log;
    error_log /var/log/nginx/error.log;
    root /var/www/mydomain/public;

    index index.php index.html;

    location / {
        try_files $uri $uri/ @php;
    }

    location /foo/ {
        try_files $uri $uri/ @php_nogzip;
    }

    location @php {
        gzip on;
        try_files $uri $uri/ /index.php?$args ;
    }

    location @php_nogzip {
        gzip off;
        try_files $uri $uri/ /index.php?$args ;
    }

    location ~ \.php$ {
        fastcgi_pass unix:/var/run/php5-fpm.sock;
        fastcgi_index index.php;
        include fastcgi_params;
        fastcgi_read_timeout 300;
    }

}