Comment on Telescopic stuff by JustV23
Observing universe trough a telescope you made yourself is the most fulfilling feeling in astronomy.
At least that's what i think.
Good luck with building your personal reflecting canon
and don't give up on it!
At least that's what i think.
Good luck with building your personal reflecting canon
and don't give up on it!
I totally agree. 
And thanks! I won't, right now I have other priorities but when I have the chance I'm gonna try my hand at pushing some glass. Have you ever considered doing any ATMing yourself?
And thanks! I won't, right now I have other priorities but when I have the chance I'm gonna try my hand at pushing some glass. Have you ever considered doing any ATMing yourself? I was constructing a refractor in my early teens.
But i failed to find needed high quality optics for it.
Well i did found them, but they cost more than buying a brand new telescope
So i decided to wait and buy a decent telescope when i will have enough money...
But i failed to find needed high quality optics for it.
Well i did found them, but they cost more than buying a brand new telescope
So i decided to wait and buy a decent telescope when i will have enough money...
Yeah, ATMing is not always the cheaper option with all the commercially available scopes on the market today. And high-quality refractor optics aren't exactly cheap, take a look at D&G Optical, and Istar Optical. Building a big refractor is a worthy goal, though! Istar Optical is more affordable in the smaller sizes, it looks like. I've daydreamed about building a big refractor like a 6 in. f/15 (I want a long focus to avoid false color). I like looking at the planets. 
I also know that you can make a refractor objective using the same techniques used to grind and polish a mirror, but not as many people do it because you need a few more specialized tools (like a spherometer) and the optical glass is harder to find. Besides, Newtonians provide the most aperture for your cost and effort. And too avoid too much false color, a large achromat has to be loooong (7.5 ft. for a 6 in. f15!), leading some ATMers to build folded refractors. Still, a traditional long-focus achromat is beautiful. Or look at this one. One thing is clear- anyone who attempts to make their own achromatic objective had better know what they are doing. XD
I also know that you can make a refractor objective using the same techniques used to grind and polish a mirror, but not as many people do it because you need a few more specialized tools (like a spherometer) and the optical glass is harder to find. Besides, Newtonians provide the most aperture for your cost and effort. And too avoid too much false color, a large achromat has to be loooong (7.5 ft. for a 6 in. f15!), leading some ATMers to build folded refractors. Still, a traditional long-focus achromat is beautiful. Or look at this one. One thing is clear- anyone who attempts to make their own achromatic objective had better know what they are doing. XD
After some simple calculations i find commercial scopes to be more cheaper solution
And me to! I love watching planets!
Deep sky objects are cool,
but to me nothing can conquer a view of Jupiter with moon shadows falling on it's cloud layers, Venus phases, Saturn's rings and of-course moon's surface
And me to! I love watching planets!
Deep sky objects are cool,
but to me nothing can conquer a view of Jupiter with moon shadows falling on it's cloud layers, Venus phases, Saturn's rings and of-course moon's surface
I've been bitten by the glass-pushing bug so I'm set on making my own optics. But that is as much for the experience as for having a telescope. I know it will take a long time and much effort to make a good mirror- but in today's world, where everything seems to be promising "instant" results, it is nice to find an activity that requires patience, care, and a lot of mental and physical effort to produce an exquisitely refined result.
I haven't observed enough DSOs to say for sure whether I prefer deep sky to planets or vice versa- so far I've enjoyed looking at everything, but just can't see enough to be satisfied.
I can see Jupiter's moons and just a hint of the cloud bands, but not the detail you describe. I've seen Titan and the other moons of Saturn change positions from night to night, but I couldn't spot the Cassini division. I love Venus's phases. The Moon is great fun even in the smallest scope, which is why we all love it- but I still want to see more.
Should I succeed at making Newtonian primary mirrors, I would like to try building a Classical Cassegrain reflector for observing planets at high power. Not as many amateurs build Classical Cass's- this one and Mike Lockwood's Cass are examples of amateur-made Cass's, though.
But that is as much for the experience as for having a telescope. I know it will take a long time and much effort to make a good mirror- but in today's world, where everything seems to be promising "instant" results, it is nice to find an activity that requires patience, care, and a lot of mental and physical effort to produce an exquisitely refined result.I haven't observed enough DSOs to say for sure whether I prefer deep sky to planets or vice versa- so far I've enjoyed looking at everything, but just can't see enough to be satisfied.
I can see Jupiter's moons and just a hint of the cloud bands, but not the detail you describe. I've seen Titan and the other moons of Saturn change positions from night to night, but I couldn't spot the Cassini division. I love Venus's phases. The Moon is great fun even in the smallest scope, which is why we all love it- but I still want to see more.
Should I succeed at making Newtonian primary mirrors, I would like to try building a Classical Cassegrain reflector for observing planets at high power. Not as many amateurs build Classical Cass's- this one and Mike Lockwood's Cass are examples of amateur-made Cass's, though.
Yes, building your own instrument is achievement by it's own.
And the views you will see trough it will be your reward.
So don't give up on this like i did
I prefer solar system bodies as live observing material and DSO as a material for astrophotography....
Well it's always nice to take a look at some globular star clusters, or brighter galaxies and nebulae,
but they can be more rewarding if instead of yourself you set your DSLR camera to look at them for couple hours
Photographing planets is also easier. It does not require a very precise alignment or tracking.
While DSO require perfect alignment and perfect tracking and dark sky far away from city lights.
It requires lots of patience and effort, but when you process your pictures and end up with bright colorful view of for example Orion nebula...
Well that is very rewarding
I have seen a video of a guy who made this... i don't know how to call it. Well it's like binoculars made of two identical huge reflector telescopes.
He made them himself and he installed a chair in between those two reflectors.
So you sit in the middle and look trough this binary lens installed between two telescopes.
It's hard to explain but it looked as huge binoculars
And the views you will see trough it will be your reward.
So don't give up on this like i did
I prefer solar system bodies as live observing material and DSO as a material for astrophotography....
Well it's always nice to take a look at some globular star clusters, or brighter galaxies and nebulae,
but they can be more rewarding if instead of yourself you set your DSLR camera to look at them for couple hours
Photographing planets is also easier. It does not require a very precise alignment or tracking.
While DSO require perfect alignment and perfect tracking and dark sky far away from city lights.
It requires lots of patience and effort, but when you process your pictures and end up with bright colorful view of for example Orion nebula...
Well that is very rewarding
I have seen a video of a guy who made this... i don't know how to call it. Well it's like binoculars made of two identical huge reflector telescopes.
He made them himself and he installed a chair in between those two reflectors.
So you sit in the middle and look trough this binary lens installed between two telescopes.
It's hard to explain but it looked as huge binoculars
Yes, it'll be the promise of those views that spurs me on through the painstaking quest to grind, polish out, and figure a practically perfect telescope mirror. So far as I can tell, figuring is the hardest part of the process. You must carefully measure the radius of curvature at different zones on the mirror using the Foucalt knife-edge tester with a Couder screen covering the mirror (basically a mask that leaves only the mirror zones we want to test uncovered), take the average of multiple measurements, determine the magnitude and nature of the remaining surface errors using that data (with some arithmetic), and then modify your polishing strokes to correct those errors.
It is amazing just how long you have to gather photons from distant DSOs to get those colorful views... I admire the patience astrophotography requires, but I don't know if I have enough patience to succeed at it myself. I like using my eyes. The biggest thrill I've had at the eyepiece so far is when I found the Orion Nebula. Seeing that nebula floating out there in space, pale white with just a hint of green- looking almost like a mote of frozen cigarette smoke- changed the way I thought about the cosmos. The Orion Nebula felt so much more real after seeing it with my own eyes, pale and small as the view was. I could feel all that vastness our Earth moves through, the baby suns being born in that nebula, the swirling nebulosity that enfolded them, the infant solar systems that might one day spawn their own life...
Seeing DSOs with your own eyes as the detector requires patience. It doesn't reward you with instant eye-candy splendor, assuming you can even find the object in the first place. If you don't use a fancy computerized scope, you have to learn your way around the night sky (which is a really awarding activity in itself). When you do find it, you have to have the patience to slowly tease out detail from what, to most people, looks like it is just a pale white smudge. But the end reward of seeing a nebula or galaxy or whatever with my own eyes (for me at least) is a sort of gee-whiz feeling that leaves me feeling truly connected with stars and galaxies. Part of the appeal is intellectual. Knowing those photons of light falling on your retina have been on their way for centuries or much longer- maybe they were on their way when the first humans emerged from Africa, or just starting their voyage when the dinosaurs perished- only to fall into your eyes at the end of their journey is a thrill in and of itself. As a little photon, what are the chances of that?
I still love astrophotography- it solves the problem with the Mark I eyeball. We just can't build up the image on our retina long enough to tease out all the color and detail... visual DSO observing and astrophotography serve different purposes. One is about seeing the universe as it is with your own eyes, the other about building up the beautiful images we just can't see without hours of light gather time.
I know what you mean, your talking about a binoscope. Those things are way cool. I have thought about the idea of trying to make one myself someday, but was a bit put off by the difficulties. You have to have two almost identical mirrors. Usually you don't care what final f/d ratio you have ground your mirror too exactly. A few inches more or less on the tube length don't matter, so if you aimed for an f5 and it turned out f5.2, it is no big deal. Not so in a binoscope. You need to combine the images in your brain, if one is at a somewhat different magnification you'll get a headache. There actually is a military standard for how closely the images in different sides of a binocular match for this reason. Buying or making matching mirror sets is a challenge. Flexure in the scopes can similarly cause trouble with combining the images. One bino-scope maker recounts how, too move from one object to another, he has to adjust the scopes for flexure after pushing the scope from one part of the sky to another. I suspect that using metal, like Bruce Sayre's scope does, helps with this. But it is clear that a good binoscope is more challenging, both optically and mechanically, than a plain old monoscope. Those binoscopes are still way cool, but I think I would ask someone more knowledgeable for help if I were to attempt to make one. I'd love to have a look through one!!
So far as I can tell, figuring is the hardest part of the process. You must carefully measure the radius of curvature at different zones on the mirror using the Foucalt knife-edge tester with a Couder screen covering the mirror (basically a mask that leaves only the mirror zones we want to test uncovered), take the average of multiple measurements, determine the magnitude and nature of the remaining surface errors using that data (with some arithmetic), and then modify your polishing strokes to correct those errors. It is amazing just how long you have to gather photons from distant DSOs to get those colorful views... I admire the patience astrophotography requires, but I don't know if I have enough patience to succeed at it myself. I like using my eyes.
The biggest thrill I've had at the eyepiece so far is when I found the Orion Nebula. Seeing that nebula floating out there in space, pale white with just a hint of green- looking almost like a mote of frozen cigarette smoke- changed the way I thought about the cosmos. The Orion Nebula felt so much more real after seeing it with my own eyes, pale and small as the view was. I could feel all that vastness our Earth moves through, the baby suns being born in that nebula, the swirling nebulosity that enfolded them, the infant solar systems that might one day spawn their own life... Seeing DSOs with your own eyes as the detector requires patience. It doesn't reward you with instant eye-candy splendor, assuming you can even find the object in the first place. If you don't use a fancy computerized scope, you have to learn your way around the night sky (which is a really awarding activity in itself). When you do find it, you have to have the patience to slowly tease out detail from what, to most people, looks like it is just a pale white smudge. But the end reward of seeing a nebula or galaxy or whatever with my own eyes (for me at least) is a sort of gee-whiz feeling that leaves me feeling truly connected with stars and galaxies. Part of the appeal is intellectual. Knowing those photons of light falling on your retina have been on their way for centuries or much longer- maybe they were on their way when the first humans emerged from Africa, or just starting their voyage when the dinosaurs perished- only to fall into your eyes at the end of their journey is a thrill in and of itself. As a little photon, what are the chances of that?
I still love astrophotography- it solves the problem with the Mark I eyeball.
We just can't build up the image on our retina long enough to tease out all the color and detail... visual DSO observing and astrophotography serve different purposes. One is about seeing the universe as it is with your own eyes, the other about building up the beautiful images we just can't see without hours of light gather time.I know what you mean, your talking about a binoscope. Those things are way cool.
I have thought about the idea of trying to make one myself someday, but was a bit put off by the difficulties. You have to have two almost identical mirrors. Usually you don't care what final f/d ratio you have ground your mirror too exactly. A few inches more or less on the tube length don't matter, so if you aimed for an f5 and it turned out f5.2, it is no big deal. Not so in a binoscope. You need to combine the images in your brain, if one is at a somewhat different magnification you'll get a headache. There actually is a military standard for how closely the images in different sides of a binocular match for this reason. Buying or making matching mirror sets is a challenge. Flexure in the scopes can similarly cause trouble with combining the images. One bino-scope maker recounts how, too move from one object to another, he has to adjust the scopes for flexure after pushing the scope from one part of the sky to another. I suspect that using metal, like Bruce Sayre's scope does, helps with this. But it is clear that a good binoscope is more challenging, both optically and mechanically, than a plain old monoscope. Those binoscopes are still way cool, but I think I would ask someone more knowledgeable for help if I were to attempt to make one. I'd love to have a look through one!!