1. LBT Q3 2007 Engineering Review INSP: Instrument Support.

2. 2 Highlights (Q3/2007) Investigated lens blackening of lens elements in LBC hubs. Italians rejected our recommendation to blacken the lens edges (for now).

3. 3 Open Issues Stray light in LBC hubs due to the un-blackened ground glass surfaces on lens elements.

4. 4 Progress Two independent experts (Joe Appels of TORC and Marty Valente of College of Optical Sciences Optical Workshop) inspected the LBC blue hub (red was inaccessible to scissor lift at the time). Both recommend strongly in their reports that the hubs should be disassembled and the lens edges blackened.

5. 5 Planning Currently gathering photometric data for various blacks on ground microscope slides. Interesting preliminary result, “Sharpie Ink” which looks completely opaque to the eye is quite translucent in the near IR. At this stage it is unlikely that any dismounting of the lens elements will take place before summer ‘08. Italians are investigating alternative option with adhesive washers for L1 and L2.