Quote:My 12" f5 does exactly the same, from horizontal to vertical there is a slight shift in collimation. I stripped the mirror and cell out and replaced the adhesive pads securing the primary with cork pads and nylon screws for lateral support. My thinking was that the mirror was shifting slightly on the adhesive pads. Its made no difference though, I still see the slight shift as I raise or lower the ota through 90°. It is slight though so I just collimate at 45° & forget about it.
12" Dob, 4" Mak, 3" APO, PST, bunch of green eyepieces & an understanding wife.
Quote:My question is: In light that the collimation shifts slightly in the barlowed Laser when changing altitudes, how accurate must I be in collimation since I clearly won't be re-collimating everytime I point the scope.
My eyepieces are made from the waste product of exploding stars. 10XTi 102XLT ST80A(2" Focuser) XW: All; XO: 2.58 Televue: Naglers-T1 Smoothside-full set, 17T4,12T4,Ethos 17,4.7; plossels-40,32,20,17,&7.4mm; Pans-22,24mm; Delos-6,8,12,17.3mm ES100: 5.5,9*,14,20 ES82: full set ES68: 16,20,24,34 NLV: 5,9,10,15 Ortho: HD-7,9; OPS-9,12 Meade RG 7mm Other: Pentax 12.5K(.965), 10mm Parks Zoom: Nag3-6 *=on b/o DAS Dark Site
Quote:Its not quite the usual setup: Its an old Tscopes with a rigid square plate and 4 point supports.
20" homebuilt truss dob 6" watson refractor
Scopes: 10" dob Antares Optics 1/30 wave secondary/Moonlite CR2, 13.1" home made truss dob Discovery optics, 4" achro (the banger)