diff --git a/app/www/index.html b/app/www/index.html
index 472e326..4d0bf98 100644
--- a/app/www/index.html
+++ b/app/www/index.html
@@ -497,6 +497,9 @@ null==d?void 0:d))},attrHooks:{type:{set:function(a,b){if(!o.radioValue&&"radio"
 	};
 	web.setExposure = function () {
 		var exposure = $('#exposure').val();
+		if (exposure === '' || exposure === null) {
+			exposure = 0;
+		}
 		var scaledExposure = scaleTime(exposure, STATE.scale);
 		$.ajax({
 			method : 'POST',