150mm MCT f/13, 31% CO
"People say I'm in denial. I disagree."
Used acronyms: NEML=Naked Eye Magnitude Limit, SQM=Sky Quality Meter, TML=Telescope Magnitude Limit, CO=Central Obstruction, delta_m=difference in magnitudes between double star components, RoT=Rule of Thumb, pD_mm=proposed D_mm for resolving a binary (ident with earlier used pA=proposed Aperture), D_mm=Diameter (of scope) in mm, UCAC4=USNO CCD Astrograph Catalog 4th edition
Quote:... A question - why have you set the CO for 254mm at 33% ? This would be unusual for a Newtonian unless of short focal ratio. Lord's 10 1/4-inch reflector mentioned in his paper is of long focal ratio, therefore is likely to have a smaller CO...