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It Massimo, I agree. What I miss is the direct comparison when experiences become collective experience, and it all results in friendship and sharing as well as a stimulant umus involving those approaching without experience and try to understand why it should take so much effort to build a mirror when you just buy it.
The results translate into curiosity and desire to understand materials at times ostiche like mathematics and physics that without a direct and palpable deferral, physical, objective as the construction of a telescope useless theories seem strange to most students.
If a young man I had not built the first mirror presume that today I'd be at the bar to review the matches…. ;-(I wanted to upload photos from google pictures and I followed the steps but I img null, what am I doing wrong?
With Google Photos you can only post the link and direct visitors to your albums / image on Google Photos, the embedded image in the text does not work, to do this you can use other types seeker free services postimage.org
https://goo.gl/photos/k5gbVj2444MU8A8Z9
try again with the entire album.
In these images there is the construction sequence of my little dob 11″, assembling and mounting to finish with the laboratory where everything happens.hello Lelio. No photo of the ones you have published is visible.
Turns out this warning:
Error 404: Could not find the requested URL on this server. No other information available.You should upload http://www.postimage and put link here, why the “Google album” probably it requires permissions that are not contained in the type of link you posted; Or GooglR album is set so that only you can access it.
Ok, Now we
Bel Dobson, I like it ,beautiful, compact and functional, great job Lelio!The photo with the chainsaw is a bit’ disturbing, I see it as a good poster of a “horror star party”
, while the best is undoubtedly the one with the “Magician” all’opera 
Now I see good pictures of the whole group.
I remember having already seen those construction (ie before painting).
And a great achievement because it is much better and robust, but also aesthetic, compared to dobbino which have drawn inspiration.On altrone the beauty of thought and dell'autocostruttore job is just to take an idea and improve it, adapting to your needs.
Too good, I modified slightly Giulio project to get you a telescope but more robust case. Breached the size imposed by the hand luggage of the airlines of the original project, I was free to increase the size of the plywood panels that are to be 15 mm and unfortunately even the weight of nearly 14 kg, but the practicality remains and also the speed of implementation. Tried on the moon with 8 mm e barlow 2,5X, until 525 enlargements still moves without jerks or jamming, if it just normal binocular eyepieces without turrets and various ammenicoli is balanced in all positions.
Photo of the “Wizard” the lab is my partner adventures, aeronautical engineer, mathematical, physical, astronomer, “weighs Pever”, as one who weighs pepper in Milan.
and perpetually in contrast with me, proponent of light wells, and he astrophotographer.Ok grattavetri, the material I received, I reconstruct the Ronchi test, and I'm ready for new adventure.
This time childbirth with two mirrors at the same time, one for me from 510 mm and one for a friend of mine from 380 mm.
It creates a new thread?
Place all the photos in sequence in a single on-line container like that of the preceding telescope?
Someone math expert and programs who want to work together for the realization of the smallest optical mirror with a different shape from newton?
I thought to gragoriano, perhaps restore a telescope obsolete with the possibilities today would be interesting?Because the Gregorian?
Why has no major defects compared to the Cassegrain, the primary is identical, the advantages there would be in the processing of secondary, concave and ellipsoid, almost a sphere.
The cons would be attributable to a greater length of the optical tube, but ease of collimation and especially straight image as in a normal terrestrial binocular, a great advantage!Great Lelio, even two mirrors at the same time
They will both Gregorian ? then four mirrors in total, focus ?
And, I think a dedicated thread is to be opened !Hello guys
In my Lelio you would do well to create two separate threads, one for each telescope.I do not know well but I read Gregory of astronomical optical clipboard Ferioli, who she was born in London in 1663 (5 YEARS BEFORE THE PROTOTYPE OF NEWTON), and has the primary parabolic drilled and the concave and elliptical secondary; then as the realization of the mirrors it should not be difficult because the secondary elliptical meets just deforming the sphere initial canonical, and overall it is a close relative of Newton.
The difference with the Cassegrain lies in the distance between the primary and secondary mirror (and then the tube), which it is a little greater than the focal length of the primary, and filling in a little longer; the spherical aberration is corrected while the coma is weak, and the image is straight.
In fact the secondary ellipse Gregorian is not simple, It must be very precise in the realization of its conic constant, otherwise we will have in addition to spherical coma .
You can think of Gregorian as the inverse of the Cassegrain:
The ellipse and the hyperbola have two fires, one of their properties is that the rays coming from a fire are reflected in the opposite fire-The cassegrain puts the focus of the primary over the secondary, the first fire of hyperbole , Gregorian before the secondary , coinciding with one focus of the ellipse.
This important property means that the system aberrations are those of primary , since the secondary does not add any aberration precisely because it reflects on the other focus the rays coming from the first fire.
So a Cassegrain or Gregorian with a primary F4 will have the same aberrations of the primary mirror, like a Newton, why we try to do these schemes with the primary too short, otherwise it is necessary a correction especially for the coma.
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