Do you agree with these two proper ways to use the crosshairs?

[pat]

There are only two ways to allign the xhairs (in sight tube) to center the spot on the primary mirror. One comes from Celestron.

1) You adjust the secondary mirror (not primary) untill the fuzzy xhairs are alligned with the primary mirror spot reflection. You can pull your eye away from the xhairs to reduce their fuzzness.

2) You can generally ignore the fuzzy xhairs. The exception is when they're canted relitive to the in-fouces xharis. If ther're canted, It means one of the mirrors are canted. When the mirrors are collimated, you should see the fuzzy xhairs and the in-focus ones pretty much coincident with one another.

IMHO it sounds not worth the effort. Pat

[umadog]

What telescope is this for? Why are there two sets of crosshairs in (2)?

If the second one is referring to the Newtonian spider as "crosshairs", which I suspect it may be, then ignore it--it's wrong. The first one is the correct way to do things. See: Rob Campbell's Home Page

[pat]

It's an Orionf4.7 reflector. The spider vanes has nothing to do with it. There is one set of xhairs in the tube (combination cheshire eyepiece). When look through the peephole you see a set of large fuzzy xhairs, also a smaller infocus reflective crosshairs. You're supposed to bring them two together or coinside. Which is a difficult task to do. Some people have learned to this. I haven't. Pat

[umadog]

I've never done it that way.

[pat]

Google- Final word on how to use crosshairs for collimation. Celestron was wrong, you use the secondary screws, not the primary screws for adjustment. I'm currious what way you are using. Pat

[umadog]

The tilt of both mirrors needs to be correct to achieve axial alignment. The sight tube (the cross-hairs) is the readout for the secondary tilt, so you adjust the secondary screws to centre the cross-hairs on the primary spot. The Cheshire is the readout for the primary tilt, so you center the primary spot in the Cheshire using the primary screws. That's the only way of doing it. John Reed Home Page Collimation - Cheshire

[pat]

I think maybe were're saying the same thing. You use the set of crosshairs first for the secondary. Then the Cheshire or colli-cap to center the spot on the primary using the adjustment screws. And if necessary iterate between the two. It was sugested to read part four from Astro-Baby Collimation. As a side note it took some calling to convince Celestron of their mistake. Venders didn't have a clear idea on the proper way to use the crosshairs. Getting to the bottom of this IMHO is a futile effert. Pat

[pat]

Adding: Closely look at picture 4 in astro baby collination.Look closely(left picture)see in-focus reflective xhairs . The problem is the fuzzy xhairs are only six inches away, but the center mark is over a meter away. It' almost impossible for anyone to focus on both at the same time. Train your eye to quickly change focus from the xhairs to the centermark and back. Eye strain has been reported. Pat