Hi Ben,

I'd say there's a great deal more you can do than simply using pb/@facs 
to point at the highest-res image; the Representation of Primary Sources 
chapter has examples of using <surface> and <zone> to link components of 
a transcription to areas on an image, and of linking to multiple images 
at different resolutions:

<facsimile>
  <graphic url="page1.png"/>
  <surface>
   <graphic url="page2-highRes.png"/>
   <graphic url="page2-lowRes.png"/>
  </surface>
  <graphic url="page3.png"/>
  <graphic url="page4.png"/>
</facsimile>

<http://www.tei-c.org/release/doc/tei-p5-doc/en/html/PH.html#PHFAX>

Cheers,
Martin

On 2017-06-18 04:24 AM, Ben Brumfield wrote:
> Dear Colleagues,
> 
> Two weeks ago, Patrick Cuba, John Howard, Peter Robinson, Jeffrey Witt 
> and I organized a discussion session on Connecting Text and IIIF at the 
> IIIF Conference at the Vatican.  While we each have different 
> perspectives expressed by our lightning talks, we agree on the need for 
> the TEI community to be involved in conversations about modeling text in 
> IIIF.
> 
> My own talk, "Text Beyond Annotations" is online at
> http://content.fromthepage.com/text-beyond-annotations-at-iiif-vatican/
> 
> I'd be interested in discussing best practices for linking from TEI 
> documents to page facsimiles hosted on IIIF image services.  At the 
> moment I think that the only option we have is to insert a URL to a 
> maximum-resolution image into the *facs* element of *pb*.  I'd like to 
> preserve that option for TEI viewers that don't support IIIF, but is 
> there anything better we could do?
> 
> Ben
> 
> Ben W. Brumfield
> Partner, Brumfield Labs
> Creators of FromThePage <https://fromthepage.com/>