How do I add Alt Image Tags to my photos? I am trying to figure out how to add alt image tags to my photos. I was under the impression that the "file name" served as the alt image tag in Craft CMS, but no such alt tags are populating...and furthermore...I really have no idea where I can add them. Can I do this from the assets field?
Out of the box, you can use the image "Title" as alt text.  Since it is already configured - you don't need to add any additional fields.  Then you can output this in your twig template as:

{% set image = image.yourImageField.one() %}
&lt;img src="image.url" alt={{ image.title }}"&gt;


For semantics, you may not want to use the "Title" field.  Or, you may be using "Title" for something else.  In that case, you can add a new text field to your asset called "Alt Text".  It will then appear right below "Title" in your image/asset editing dialogue.  

{% set image = image.yourImageField.one() %}
&lt;img src="image.url" alt={{ image.altText }}"&gt;