Respect! Thats the spirit of John Dobson and amateur (!) telescope making. Thanks.

I keep thinking of Laura Palmer. This is the first time I've seen the chemical deposition of silver to create the mirror surface.

Fantastic video. Very nice to see an India video from IUCAA India on a science which has rich traditions in India. I currently own a Skywatcher 8" and have owned quite few smaller ones since my school early college days and all my own pocket money !! My daughter too enjoys this hobby whenver I now get the chance to set it up and watch the skies from my busy daily life and job !! Great video have subsribed for more such good videos !!

I read about this over 50 years ago but had never seen it demonstrated. It is simpler than reading about it. Thank you.

I am so impressed by your skill and resourcefulness. Have always wondered how this was done by hand. Brilliant, thanks.

Wow, it's rare that I actually watch a video twice in a row, but I'm watching this one again.

Extremely informative video. I hope you will upload more telescope making video in time.

Great video. Back to basics method for creating a telescope. loved it

15:11 "for those who are spectacular like me" hahaaaa, great one

Good video. Thank you for taking the time to make it.

He gave some very good information about removing his eye glasses. I have watched so many times as people try looking through binoculars while wearing their eyeglasses, which it totally un-necessary.

This was another great video on the path to building my own reflecting telescope. Accent and all, I was able to interpret the information presented. Thank you, Mr. Arvind Paranjpye and your student for taking the time to share this knowledge Well done. Bobbym59

What an excellent documentary, thanks for your time

This is a gem. This is what youtube was meant for

This looks so fun..much respesct ty sir from USA. ❤

amazing work .. by you guys.. i am also going to buit my 8" telescope.

Thank you and your students for making this informative video , good luck with your skywatching .

this was a grate video, thank you for posting it - cant wait to try it with the kids

I loved the video! Great information!

I am a physics faculty used to teach students of class XI & XII. I must say, it is a very useful and informative video.

NICE! Really economical, and delivery is professional. Thanks so much. Of course, I speak in the name of the "Movements" of the 21st Century. Basically: search for Higher Power (secret name of such movement, and separate oneself movement.). Again, Good job. Complete, within all's means, as well as not verboise. Praise to YOU all, and secret name of [your] Higher Power.

I've been wanting to make my own for years gonna have a go after watching this

I'm not seeing the two daughters bouncing out to the club anytime soon. Lots more grinding left to do.

Thank you for posting. I found it most interesting,

I can listen to this guy all day! I love the Indian accent!

That's fantastic . Paranjape Sir is always great.

Great work Arvind...

Thank you for sharing this amazing Technique to prepare primary mirror.

Thank you so much for this beautiful video. Very informative I am trying to create a telescope myself and this was a great help.

Dear Mr. Arvind, I am delighted after seeing this video. Thank you for posting it, thank you for doing what you do, and thank you for being who you all are. It is refreshing and encouraging to see female students involved in science and astronomy. I intend to check the availability of carborundum powder, as well as the basic glass disc blocks here in Israel, but I feel much more confident that I can do it and, hopefully, get my bright grandson (with the Angry Birds hat in the picture) interested in astronomy. A heartfelt thank you to you and your great team. Great work!

This is an excellent video. Thank you for posting. You use slightly different methods than I use. I learned something watching your video. I hope that the young ladies are enjoying their telescope.

This is a very interesting video... Great work! By the way, a well calibrated spherometer will guide you towards your goal radius of curvature regardless of the sunlight test. It's good to do both tests anyways... but the spherometer, if small enough, will give you the different radii of curvature of each point of the surface. That way you can tell how the curvature changes along the surface, giving you an idea of the surface figure while grinding... Quite enlightening...

Beautifully done.

You really are spectacular sir :-p !!! Nice Vid!

thank you - nice simple explanation

excellent video sir

This is why America is behind in science and math, I would have loved this on school

I will continue my a mature research with this video. Thank you very much guys! Omg! You answered all my questions.

afarin, besyar besysr khoob bood👍

Good tutorial to learn making of Telescope mirror ..

An indian tutorial as always GOD DAMMIT

I have read, that after grinding, the shape of the mirror is spherical. Because one needs parabolic mirror, there should be additional grinding at the rim. This kind of putting the reflective coating is relatively easy to make for people like me. Otherwise, there are other methods using evacuated vessels. Thank you for sharing :)

This is fascinating & my respect sent to anyone who makes their own lenses by hand . Thank you very much .

Hi Mr. Arvind. I'm starting build mine too. As of now I'm trying to understand how lenses and Newtonian telescope works, while doing that I'm also thinking of alternatives as abrasives for grinding the mirror. I find sand a good one as we have bunch of sand here for construction purposes, but I don't think I can reach the 2000grit something by just using my mother's marble mortar pestle and also time consuming. So my solution to have a shiny surface will be once I almost reach the curve to make it parabolic using fine sand, I will use some low grit sandpaper like 500 until the previous scratches are shallow enough for 2000 to make it shiny enough to polish. Am I doing it right??? LOL I saw some dudes doing it to their car headlights, I hope it also work the same to glasses. Based on what I read, the ideal size of the mirror for beginner builders like me is 20cm diameter. If I succeeded then I will do the biggest I can make since I pretty much know how the telescope works and made. The glass type I'm gonna use is tempered one tho. Please tell me if it's wrong to use. Btw I'm living near the equator and seeing a blue sky is just a normal day to us so not that much particles that might affect the image quality, we live in 3 storey house and I find the terrace boring having one gives people around here sth fun to look at. The eyepiece part is really bugging me. As of now I have a very blur idea how it works. I hope I can make an improvised one for my mirror or else I'm going to be forced to buy one. Don't wanna spend as much as possible. But anyway I'm documenting the whole progress from scratch, If lucky that succeeded I will share it so everyone can do theirs too to see what's up in there and ofc out of available materials we have. Sorry for long comment.

very incormative thank you

From where do you source the glass blanks in India? Also is there any supplier that aluminise the polished mirrors?

Awesome video, good job to everyone involved. Really inspiring to see hand-made equipment!

Молодцы какие девчонки, в каждой бы школе так

What a classic 👏🏼

Nice interesting work👍👍👍👍👍👍

Focal length check...that is a cool technique!

I love the music from twin peaks

Excellent, I am glad you're teaching (young) people to do this. Working with the hands, and these kinds of skills need to be promoted. You made silvering look easy, I am almost tempted to give that a try.

This was very informative and interesting to watch. It was good to see the girls learning these skills. One question I have. The silvering process seemed to result in a kind of blotchy and dull surface. Can the surface like this be used in a telescope? Mirror surfaces are normally quite uniform and reflective.

Sir, which kind of eye piece is correct for reflecting type telescope?Normal convex type or ready made eye piece which is used in camara or microscope?

Dear sir,Will you tell me which is the best focal ratio for 6 inch,8 inch,10 inch mirror blanks for home made reflecting type Newtonian telescope?what is the best thickness for mirror blanks?And which side i should silvering? Arvind Patel(Gujarat)

Fantastic Arvind!!!

Dear Sir Arvind, this is a very inspirational video for an astronomy student like me to create a telescope from scratch. It would be immensely helpful if you could guide me through the entire procedure. Once again, thanks a lot for the video

I have a 12 primary mirror from celestron which needs recoating, but nobody in my country is qualified. How do I proceed with removing the old oxidized aluminium coat an putting a new silver coat. Can you advice ? Else I will have to buy a brand new telescope..

WOW THAT IS AN AWESOME LECTURE

Dear sir, I visited IUCCA when I was in 9th std, our school visit, it was v inspiring indeed to see the institute and the newton's apple tree in the garden 🙏🙏 I am planning to make my 1st telescope I have RC8 inches by GSO at the moment but want to make my own, will surely ask questions if I am stuck...

Super! Keep up the good work sir! :-)

Where do i get the tool to grind the glass? Lovely video thanks

respected sir thanks for precious knowledge

This is very good.... Thank you

very interesting video

Great work. Thanks

Great work sir. I made refracting digital telescope but not astronomical. Since than I am searching to build reflecting one. Thanks a lot. I thought no one build such thing in india.!!!

A lovely tutorial... Thank you all

You make it look so easy. I might havd to give that a go. Brilliant job mate.

Is it ok to use silver nitrate for silvering mirror? I heard it can be dangerous.

A very good video.

I love the twin peaks music at the end

Good stuff guys

brilliant, i wish i studied with u people.

Do I understand correctly that both your glass blanks begin flat? That there is no "form" to polish against? Is the profile a natural consequence of the grinding technique? Thank you for the video.

Sir what kind of glass did you use, just a ordinary glass blank or Pyrex blank?

It must be great feeling watching sky with handmade telescope

Dear sir please reply, What would be the segitta of a 12inch mirror??

Is this anyhow possible to silver on top of any plastic surface? Please respond

How does this grinding method ensure that the glass will have a spherical surface rather than any other concave profile?

Wow, great work

And it's... Badalamenti! ❤️

Hello... I will be visiting India at the end of May-through August of this year. Would love to visit your facility to learn and help with instruction. I will be in touch in the next next month.... Best regards, John Lightholder

Please tell me on which part should coat the mirror

Excellent simple video, can u please give details of subtances and procedure on how to silver the polished mirror like vinaya did in video ... thanking u

i want to be a student of this respected man

Sir, thank you for sharing such a valuable information. Sir,can you suggest me whether a chromed surface can do as a mirror. What can be possible shortfalls.

How to make the polishing tool ? What is this black liquid. ? Thanks

I feel like this guy is explaining to me how to achieve the avatar state.

in which step of make mirror, I can use sandblast?

can you tell me how to determine what your Sagitta should be i have an 8.5 inch blank i am going to be working with thank you for sharing your time with us.

fantastic

Hello sir Can you please tell me Where do we get carborandum in India Or any local stores in india

Hello sir, where can i get these blank disks? or do you sell any of these disks already made? i'd like to build a telescope

super document

This show is good for class

Great Video and Tutorial...

Sir, What are the chemicals that used for the reaction

Sir ..where can I buy the lens.I am planning for a 20inch Scope...