Hi Dave, I ran across your comment concerning refractor collimation on the ES YT video. I'll be struggling with this soon, as I'm buying a used ES80mm triplet from a friend. As best as I can understand, it's a little like standing between two parallel mirrors that face each other. If the mirrors are exactly parallel, their images of each other are centered and continue to infinity. If they are not exactly parallel, the reflections will trail off in one direction. The Cheshire cross hair seems to do the same thing... I think. Time will tell, as I'll be getting my scope and collimating eyepiece soon. BTW. I really like your biking video. I grew up on the banks of the Barge Canal (Erie Canal, See song link) and spent many days biking and canoeing there. Lots of history on those old canals. Clear Skies! ua-cam.com/video/SDvYBCZwMIk/v-deo.html
Hi Tom, Thanks for your comment. So it relies on a reflection from the inner most lens element? Personally i think the best option for collimating a refractor is to use a bright star, or an artificial star (a decent fibre optic one). The collimation process shouldn't that difficult, but to rely on the reflection from a cheshire tool? Not a fan of that method at all. I collimated an air-spaced doublet on Polaris some years ago and got it pretty spot on.... massively improved it. Just make sure your new scope has air spaced elements and not oil spaced and you should be good to go. Wow you must have dug deep for the cycling vid. I miss living in Bath near the canal. Bracknell Forest, although nice, has a fraction of the charm. Good luck with the new optics!
Thanks Dave! I'm just guessing about the Cheshire. Collimating refractors is all new to me. I have lots of experience with newts and SCTs, though. I have an artificial star, but I've always found collimating on a star at high powers (no diagonal) to be much easier. What you describe sounds like the same process. I'm greatly relieved. So, I'll try col using the airy disk refraction rings. :-) I watch anything about bike trails. England is very picturesque. Tom
@@tomwall8403 You sound fairly well versed in collimation. Also so worth checking the focus tube alignment and how well the Cheshire is aligned too but you probably already know this. I don't envy you at this point. Best of luck with it.... Let me know how it goes.
Hi Dave,
I ran across your comment concerning refractor collimation on the ES YT video. I'll be struggling with this soon, as I'm buying a used ES80mm triplet from a friend. As best as I can understand, it's a little like standing between two parallel mirrors that face each other. If the mirrors are exactly parallel, their images of each other are centered and continue to infinity. If they are not exactly parallel, the reflections will trail off in one direction. The Cheshire cross hair seems to do the same thing... I think. Time will tell, as I'll be getting my scope and collimating eyepiece soon.
BTW. I really like your biking video. I grew up on the banks of the Barge Canal (Erie Canal, See song link) and spent many days biking and canoeing there. Lots of history on those old canals. Clear Skies!
ua-cam.com/video/SDvYBCZwMIk/v-deo.html
Hi Tom,
Thanks for your comment. So it relies on a reflection from the inner most lens element? Personally i think the best option for collimating a refractor is to use a bright star, or an artificial star (a decent fibre optic one). The collimation process shouldn't that difficult, but to rely on the reflection from a cheshire tool? Not a fan of that method at all. I collimated an air-spaced doublet on Polaris some years ago and got it pretty spot on.... massively improved it. Just make sure your new scope has air spaced elements and not oil spaced and you should be good to go.
Wow you must have dug deep for the cycling vid. I miss living in Bath near the canal. Bracknell Forest, although nice, has a fraction of the charm. Good luck with the new optics!
Thanks Dave! I'm just guessing about the Cheshire. Collimating refractors is all new to me. I have lots of experience with newts and SCTs, though. I have an artificial star, but I've always found collimating on a star at high powers (no diagonal) to be much easier. What you describe sounds like the same process. I'm greatly relieved. So, I'll try col using the airy disk refraction rings. :-)
I watch anything about bike trails. England is very picturesque.
Tom
@@tomwall8403 You sound fairly well versed in collimation. Also so worth checking the focus tube alignment and how well the Cheshire is aligned too but you probably already know this. I don't envy you at this point. Best of luck with it.... Let me know how it goes.