don't lose the thing we're attaching the photo to when we change sets. This is a modification of oshiho3's previous fix.

app/views/photos/new.html.haml

@@ -15,7 +15,8 @@
       = form_tag(new_photo_path, :method => :get, :class => 'form-inline') do
         = label_tag :set, "Choose a photo set:", :class => 'control-label'
         = select_tag :set, options_for_select(@sets, @current_set), :class => 'input-large'
-        = hidden_field_tag :planting_id, @planting_id
+        = hidden_field_tag :type, @type
+        = hidden_field_tag :id, @id
         = submit_tag "Search", :class => 'btn btn-primary'
 
   %div.pagination