I am relatively new to ADFS and have a question. We need to have both NTLM and ADFS authentication in our 2013 environment. That means it appears we'll have to tolerate the sign in drop down page where users have to select their authentication type. Some on our team were hoping we could implement ADFS at a level lower than the web app, such as on a site collection level, so only users accessing that site would be presented with the authentication sign in.
From everything I have read, it seems like you can't do. ADFS has to be turned on at the web app level. The other thing I thought of is even if you could turn it on for just one site collection, what would happen to the ADFS user when they went to another site collection? They would have to use the NTLM authentication, which would result in a completely separate user account. My question is, is there any way to limit ADFS to just a single site or site collection within a web app, or is it all or nothing from the web app level?