I am planning to purchase a 180mm refractor from a German, French, Italian, Japanese or American manufacturer. So far, I have narrowed my choices to 3 models, which all appear on the surface to share some DNA since some of their specifications are so blatantly similar. Following are my 3 potential choices:
1) APM (LZOS Design) 180mm f/7; focal length: 1260mm; tube diameter: 8.5 inches 43 pounds.
2) Stellarvue SVX180T; 180mm f/7; focal length: 1260mm; tube diameter: 7.95 inches; 40 pounds; guaranteed to an accuracy of .99 Strehl or higher.
3) TEC APO180FL; 180mm f/7; focal length: 1260mm; tube diameter: 8 inches; 36.5 pounds; theorical resolution: 0.66 arcsec and the only one offering a special Gutekunst Compact Atmospheric Dispersion Corrector out of the gate and the only manufacturer displaying the theoretical resolution of the instrument.
Stellarvue guarantees an accuracy of .99 Strehl or higher; however, APM and TEC offer similar specs, which are a hair under the advertised Stellarvue claim. If I were looking for a 150mm instrument my choice would have been the TAKAHASHI TOA-150B REFRACTOR; however, this is the largest offering from TAK. My main goal is optical resolution and optimal quality since I plan to mate the SBIG Aluma AC4040; BSI Class 1 Sensor camera to my instrument of choice and will be mounted on a PlaneWave L-500 Direct Drive.
Since this is going to be a lifetime acquisition, I certainly would appreciate and welcome any thoughts from the group related to your experiences with these wonderful instruments and manufacturers, including the instruments and respective customer service experience. I have learned a lot just from reading some of the members’ posts. Cloudy Nights has some expert members, which truly step out of the box in a very responsible, scientific and unbiassed fashion to offer data only found in professional astronomy resources. I have also settled on a refracting instrument since I prefer not to deal with the maintenance and idiosyncrasies of reflectors; however, I am fair game to reflector enthusiasts and willing to listen to you all. Thank you all in advance; keep this wonderful site moving forward and I look forward to your responses.