Astronomy
My 10 inch Mirror with a 1/48 P-V Wavefront Error @ 550 nm
What a bonus, I put extra effort into the production of my lens, and complete strangers recognized the results and saw fit to compliment me for it. Here are the specs on my Mirror when used with a 2" Flat:
Independently Measured Wavefront error ...1 / 24 P-V @ 550nm ( 1 / 48 on the mirror's surface )

Property	Mirror	Clear Aperture
Diameter: Focal Length Focal Ratio Light Gathering Power Stellar Magnitude Resolving Power Diffraction Limited Resolution Useful Magnification Range	10" or 254mm 54" or 1372mm 5.4 2500X Brighter than unaided eye 14.72 0.47 seconds of arc 276 lines / mm 50.8X  to  508X	8" or 203mm 54" or 1372mm 6.75 1024X Brighter than unaided eye 14.24 0.59 seconds of arc 220 lines / mm 40.6X  to  406X

Note: Mirror is mounted to take advantage of its entire diameter of 254mm
Note: Ideal "seeing conditions" limit ground based telescopes to a resolving power of 0.50 seconds of arc.