Here's the FRED file of the Orion Apex 90 Maksutov Cassegrain telescope used in the book and short course. The prescription of this telescope has not been published, therefore, the prescription used in this file is an educated guess. Though the stray light performance predicted by the FRED model agrees well with the measured performance of the telescope, it's difficult to determine how accurate the model is; therefore, use this data at your own risk (full disclaimer of liability given below).
Disclaimer of Liability
This data is provided “as is” without any warranty of any kind, either express, implied, or statutory, including, but not limited to, fitness for a particular purpose, or any warranty that the data will be error free.
In no event shall Phobos Optics LLC be liable for any damages, including, but not limited to direct, indirect, special, or consequential damages, arising out of, resulting from, or in any way connected with this data, whether or not based upon warranty, contract, tort, or otherwise, whether or not injury was sustained by persons or property or otherwise, and whether or not loss was sustained from, or arose out of the results of, or use of, the data provided hereunder.