I am trying to define the action "savenew" in admin/photographers controller.
I have tried this:
<%= simple_form_for(:photographer_savenew, :action => 'savenew', :id => params[:id], :multipart => true ) do |f| %>
But the action in the form is still: /admin/photographers
When it should be: /admin/photographers/savenew
Is there a reason you're not using REST for this? It would make your life a lot easier and requires much less code. If you're set on using this custom action, you will need to specify the url and probably the method:
<%= simple_form_for @photographer, :url => savenew_photographers_path, :method => :post ... # etc