Scorch,
I don’t know if you figured this one out yet, but there is an amazing plugin called ‘RICG Responsive images’. And that plugin works great with ACF.
After installing the plugin, all you have to do in your template is:
$image = get_field('your-image-field');
$size = 'medium'; // (thumbnail, medium, large, full or custom size)
if( $image ) {
echo wp_get_attachment_image( $image, $size );
}
(Make sure to set the return value of your image field in ACF to ‘Image ID’.)
This code returns the appropriate <img /> tag including all parameters you need (srcset).
