Stained Glass Dome

[Blasius1101]

I am currently involved in a large-scale restoration project of a Tiffany Stained Glass dome.  Although the dome was originally covered with a skylight and lit with natural light, cast concrete panells and a copper skin were installed in 1935.  The dome was then "lit" from above with artificial lighting that ran between the concrete and the art glass.  Would anyone be aware of any situation similar to this one?

[John]

That could only be the Preston Bradley Dome:

http://egov.cityofchicago.org/city/webportal/portalDeptCategoryAction.do?BV_SessionID=@@@@1227863611.1204250099@@@@&BV_EngineID=cccfadedhffjeemcefecelldffhdfgk.0&deptCategoryOID=-536900432&contentType=COC_EDITORIAL&topChannelName=SubAgency&entityName=Cultural+Center&deptMainCategoryOID=-536900432

Make sure to check out the image galleries.

The bulk of the panels are partly opalized tight ripple with embedded irregular clear glass chunks plated to small pieces of colored glass.

When diffuse backlighting hits tight ripple and prism-like glass chunks, they look flat and dead, which is the way the room looked before the renovation.
 
When sunlight hits tight ripple and prism-like glass chunks, they sparkle like crazy, because sunlight rays are virtually parallel and the glass behaves like a sheet of irregular lenses.  The chunks should sparkle in colors as you move through the room and might throw rainbows.

The 1940s decision to cover the dome with a copper skin completely ruined the intended effect of the dome.  The current backlighting is abysmal and completely washes out and makes the entire dome look flat and uninteresting.   

When the new transparent dome is installed, the glass should sparkle in full sunlight and be absolutely dazzling.  I'm thinking that the sparkle is going to play off the shiny mosaic tiles covering the walls as well.  I'm predicting that it's going to be spectacular.

In short, it's been 70 years since this dome has looked anything like the way it looked before it was covered.  If everything goes as it should, the new presentation should be a revelation!