I had a great question from Erik Barone at ESPN this week.
He's been working with Autocue and Autoscript prompters for years and he needs to keep them working at peak performance. His specific question was regarding the glass in the hood and the recommended way to clean and maintain the prompter beamsplitter:
"Is it ok to clean the prompter glass with Windex or something similar and paper towels?"
There are coatings on both sides of the beamsplitter glass that can be damaged if an ammonia or bleach based cleaner is used. Windex is generally ammonia based, but there is a vinegar based version of Windex that will do the job well. Generally, though, warm water is all we recommend unless the glass has an adhesive or other hard to remove soiling. Lens cleaner is preferred if a cleaning agent is required.
Another common source of glass issues is the cleaning implement. If an abrasive material is used, the coating can be rubbed off over time. We find that materials with particulates act as abrasives and paper towels, napkins, and other processed materials fall into this category. It's best to use soft, fibrous materials like cotton, microfiber and chamois. The cloth included in the lens cleaning kit is preferred.
When the beamsplitter glass coating is removed or has been damaged, it will show a couple of symptoms in the camera image:
- Cloudy spot if reflective coating is damaged
- Lighter or color-shifted spot if reflective coating is removed
- Lens flares if non-reflective coating is removed
- Reflection of elements inside the hood if non-reflective coating is removed
And a couple of symptoms in the reflected image of the prompter monitor:
- Blurry spot if reflective coating is damaged
- Dim spot if reflective coating is removed
If the beamsplitter glass coating is damaged - even in the tiniest of spots, the entire pane will have to be replaced, so proper care of your beamsplitter glass should be a very high priority. If cared for properly, each pane can last for decades without any loss of performance.