I have secured (HTTPS) ASP.Net MVC 4 application that uses unsecured (HTTP) ArcGIS map services. These services are called using JavaScript to get relevant map images. 

If I use HTTP for my app, everything works as expected. But if I use HTTPS, IE10 and Chrome do not display the requested map images (IE prompts to display unsecured content) but Safari shows the image, no questions asked. 

As an example, say my application is **https**://app.mydomain.com and my map services are at **http**://gis.mydomain.com 

I run fiddler and see the response as something like (removed some parameters to simplify): **http**://gis.mydomain.com/arcgis/rest/services/Energy/BaseService/MapServer/export?....&f=image
but the image is not shown. If I enter this URL directly into my address bar, the expected image is shown. 

There are no errors reported anywhere, including IIS 7.5 logs. I realize that mixed content is not ideal but I have no option at the moment. I have found lots of references to SilverLight with regard to this type of problem, but I am only using javascript and ASP.Net. I also compared the page source for both https and http - there is no difference.