Hey guys. I have a ir flashlight with good throw and my new discovery scope came with a cell phone mount. I was wondering if any of you had any ideas on a cheap used smartphone that is easy to get to the red filter. I have a htc one but it requires heating and I am not even sure it has a red filter or if its built into the glass. At any rate if any of you have gone through this process and have some hints id be grateful I am saving up for a nightsight but as you know that cost some serious shekels. Ty