XT10 classic with premium optics Tri-knob CR2 focuser
Catseye + Glatter collimation tools
StarBlast 4.5" & 6"
Round Table Platform
I'd rather be driving my .
Quote:I will relate the info provided in the previous post to reflectors.
Quote:So what I take from this is that it is possible to compensate for a rotated secondary by using the standard secondary collimation screws and in fact this will happen through the standard secondary collimation process.
Quote:...I do believe, however, the amount of adjustment possible in typical scope will still require that the initial rotational error be minimal so in reality it is not possible to compensate for gross errors. For example, I know my secondary collimation screws aren't capable of inducing anything close to a 10° rotation of the secondary mirror and thus they aren't capable of compensating for such a gross error.
Quote:In the end one should still try to get the rotation as close as possible when installing the secondary but one does not need to obsess about it being perfect as standard collimation procedure will correct any minor error.
Quote:...That is why we obsess over what amounts to very minor issues that we probably won't even notice at the eyepiece.
Quote:While the experts are on board here, here is a question about secondary rotation...When using a laser to set the secondary rotation, the laser spot follows an arc across the primary as the secondary is rotated. It seems to me that the correct rotational position of the secondary would be where the laser spot is directly above (on the focuser side) the center spot. On my diagram, that is where the dashed line and the red arc intersect. Any comment?Steve
We mostly come out at night... mostly.
GSO Z8 Degree Circle & Digital Level
Celestron 4"(102mm) SLT 660mm f/6.47
2" 30mm GSO WideView
9mm GSO Plossl
ES 82's : 4.7mm, 8.8mm, 11mm, 18mm
BGO's 5mm, 6mm, 9mm
2" 2X ED Astronomics Barlow & GSO 1.25" 2x Shorty
8-24 Baader Zoom III
Baader M&SG, Semi-Apo
Quote:...So, pardon me Please. Is there a simple grounded take away from this fine discussion? Do this to the secondary mirror, but no, don't do that?
Quote:FWIW, "this fine discussion" was started with the opening salvo, "First, the following two posts are not intended for everyone. Feel free to ignore this thread if you wish." I believe Jason knew this discussion (even with his excellent graphics and animations) could become mired in the details and he felt compelled (justly IMO) to start with that cautionary opening.
woody a parsec farther out... 12.5" f/4.8 custom truss dob, EQ platform
Stellarvue 80ED (2.5" focuser)Stellarvue 102BV (Feather Touch focuser)
Orion StarBlast 4.5 EQBurgess 1278 (MoonLite CF2B focuser)Hardin 10-inch Dob (GSO Crayford Focuser)7x50 BinocularsThe heavens declare the glory of God, and the sky above proclaims his handiwork.