With those criteria in mind, what classic 4" long-focus refractors do you think fill the bill or are totally impressed with?
I'd prefer to hear about the ones that are actually found more often rather than the uber-rare AP's and Zeiss iterations.
Matty.....with your objectives in mind (Yes pun intended) I have experience with four long focus refractors from the 50's. I will rate the ones I own on the following merits: Optical quality, Mount quality, ease of use and setup, overall craftsmanship and value for the dollar........So five categories.....keep in mind I am only rating the actual scopes I own. All four are complete kits.
Goto Model 204 circa 1957
Unitron 150 fork mount circa 1955
Unitron 155 circa 1955
Edmund 4" circa 1958
Optical quality: 1: Goto 2: Edmund 3: Unitron.................The Goto's optical polish and figure are excellent....The Edmund is also excellent and honestly could have been sourced from Goto (who knows) one of my Unitrons (155) is good but I have owned two other Unitron 100mm objectives that are downright poor.
Mount quality: 1: Goto 2: Unitron 3: Edmund...........The Goto's fit, paint finish and mechanical quality are excellent.......the Unitron is a close second....The Edmund mount works and has good mass but crude by Goto's and Unitron standards.
Ease of setup 1: Edmund 2: Unitron (150) 3: Goto 4: Unitron (155)........The Edmund is the lightest of the three, especially the OTA which makes it very easy to setup and cool down time is excellent. My two Unitron OTA's are both brass and very heavy.....The Edmund tripod legs are maple very solid and Goto's are likely oak or other hardwood....Unitron is unknown but good and solid.
Quality of overall mechanical craftsmanship 1: Goto 2: Unitron 3: Edmund
Value $: 1: Edmund 2: Goto 3: Unitron
I still own all of these and have tested them side by side and tested with DPAC on numerous occasions...... While my Goto model 204 is the top of the class (of my four) it is rare to find especially in a complete kit. With that in mind your best chance of finding one in my opinion is a Edmund or a Unitron. Just be prepared to find the 100mm objectives are hit and miss with all manufacturers..........You have to test to confirm the optical quality.
Edited by PawPaw, 24 January 2022 - 09:14 PM.