Optical Lens Centering using a LOH LZ-80.

This video discussed the theoretical- and practical aspects of lens centering. The video features a lens triplet from the telescope corrector .
Unfortunately it turned out that after my Loh LZ-80 centering machine was brought back to operational status the lenses were already correctly centered. The cause for their poor performance was actually in the construction of the optical tube holding the triplet. So in the end, centering of the lenses turned out to be unnescessary.

[@TimVT971]

Your videos, for the right crowd, are pure gold. Thank you! The discussion about the issues with the lens tube are quite helpful.

[@tolga1cool]

They are really awesome even if you're there wrong crowd. I have no plans to ever make my own lens, however I really enjoy the technical videos and calm explanations

[@lst141]

Even for the crowd that is not into the business. Do you think that Louis rossman, an apple repair man that has almost 2 million subscribers that repair MacBooks!? It’s how he presents things, absolutely precise even if you do not understand a piece!.

[@CaskStrength777]

I love how you turned the machine into an extremely accurate lathe using a micrometer xyz stage as your toolholder. You definitely have training as a machinist somehow to deduce you could do that. Cutting geometry and relative motion are all that is ever needed for cutting action- and sometimes you find unique ways of presenting that reality to your workpiece- like you did here. Especially liked the indicated tap trick. Your channel is definitely niche, but full of creative genius. Bravo for posting again what you already do, fascinating stuff

[@csours]

I laughed so hard when I saw that. Finest Quick Fix Engineering I've ever seen!

[@mohammadbarani5452]

For some reason which I do not know exactly why, watching your step-by-step work and learning about how you strive to do something different, new, and interesting gives a feeling of excitement, joy, and satisfaction. Beautiful job.

[@opticalmechanic]

I worked on an LZ80 when I was an apprentice. The appearance of the machine always reminded me of the robot from Lost in Space.

[@joeo6378]

Had me laughing at the end. The dejected look and poking that giant machine. Like a kid that gets a new toy but no batteries.

[@1h1oh34]

Just found you…magnificent channel…can’t wait to have time to peruse…

[@wwjjss33]

A shop I worked with used their Bridgeport Type II mill as a make-shift CNC lathe by placing rod material in the collets and mounting lathe tools in various custom blocks in the Angle-Lock vise--using the mill as a vertical CNC turning center ;) Love your content! I just subscribed.

[@MrMilarepa108]

Loved the end where you sit bored next to the machine. So funny 🤣 Hope you get some new lenses to center that are actually wrong.

[@jedimastersterling1]

I totally called the precision machining the cups in situ. They do the same thing for mill tables. Awesome trick.

[@roguethinker6284]

I love your channel. I have always been interested in optics and telescopes and the knowledge that goes into them. Thank you for feeding my brain lots of great material!

[@davidkierzkowski]

Great video nice machine lots of specialized knowledge

[@brothertyler]

I really enjoy your videos because of the straight and upfront technical manner of them, thank you for posting them.

[@uscindia9808]

Sir You are my professor in optical engineering field .....explained with high efforts theory With practical......Keep posting such a knowledgeable video ..... Regards Shall san Mumbai India

[@babylonfive]

Love your videos... enjoying them all in retrospect!

[@ViceChief]

Such a great video. Thank you for making these videos.

[@movax20h]

That was so funny and educational. The use of the make shift accurate lathe was interesting too.

[@rogeronslow1498]

Great video. Very specialised work and out of my field but still fascinating. Thanks for sharing.

[@sebaschtl9710]

I'm so glad I found your channel. Great work. So beautifully explained and funny!

[@denispol79]

What a lucky friend you got! I also want a friend that is a highly experienced optics builder

[@ericlotze7724]

I love the combo of old machine with new pc.

[@glentyan2505]

Excellent video, very informative and a true craftsman.

[@Moonblade042194]

GREAT VIDEO! Thank you so much for sharing your knowledge and experience!

[@TecKonstantin]

Always enjoying your videos! The ending was great :)

[@reps]

So this is where all the cool kids are hanging out these days ...

[@TecKonstantin]

dito, more like since i was a kid ;),

[@Dukey8668]

@@reps I was just thinking of you while watching this video - you and OP have a very similar style.

[@ericwebster6911]

This is pure genius!

[@seraphin_creates]

such awesome content on this channel! thanks!!

[@trident8872]

Very valuable information you have shared

[@darkwood777]

Nice video. I would like to see more info on the subject as it pertains to chromatic aberrations in triplet telescopes.

[@rolfzimm3467]

Excellent video!

[@rexmundi8154]

I’m loving these videos!

[@repbacchista]

just awesome, i love to watch the processes, thank you very much sir

[@Vikingman2024]

Outstanding! Always learning...

[@antoniorodolpho6835]

What a wonderful channel !

[@CameraRestore]

Amazing job! Lens calibration on camera lenses is a big problem, most of the time because of this I skip the repair or change the whole new group, I would like to find a way to calibrate camera lenses, I knew about the laser but no much information about it Thank you for sharing

[@fatihdurmaz9826]

thank you so much for uploading

[@geraldthompson3421]

Brilliant explanation. Thank you...

[@KantidMM]

Well done. It was very interesting!

[@Rich-hy2ey]

Good work, I hope he reported back to the (expensive) telescope company that their compressor/field flattener housing was flawed.

[@ericlotze7724]

The fact these machines sell for so little astounds me.

[@samsmith9764]

i know right, that thing sold for less than its scrap value by the looks of it

[@Gabriel-yd4bq]

@@samsmith9764 Probably someone wanted to get rid of it

[@lucianovasco4654]

Bom dia, quero parabenizar você por conseguir entender e resolver os problemas que foram aparecendo. Tenho inveja de você por isso, já desanimo quando minhas soluções não dão certo da primeira vez. Parabéns.

[@davesmith9325]

Excellent video. In some ways sad it ended being for nothing but you (and now we!) learned some stuff. It's all interesting

[@Karebear9001]

You may find some of the old cam driven lathes and old fire control computers interesting. Iirc there’s an old us navy video on YT that has a very nice explanation of how a function is translated into a cam surface.

[@campbellmorrison8540]

I am very fascinated with your videos, the most detailed explanations I have seen anywhere. I especially liked your OLED one. I wonder if you or somebody else might explain why many lens are made in multiple pieces and then glued or pressed together, is it only to use different refractive properties of the glasses or are there other reasons?

[@BartSliggers]

Yes this is mostly done to compensate for (chromatic) aberrations. Ideally the dispersive properties of a doublet or triplet should cancel each other out.

[@ricardommyamada]

Amazing!! Very Good!

[@extradimension7356]

This video is pure awesomeness / a real scream , at least three very good quotes. (Very funny / cool). Awesome Hacks with using the spindle on the centering machine for final cut on the cup and also measures for concentricity / roundness. @Huygens Optics what do you estimate the size of your laser spot to be ? Wasn't clear where the reflection for optical axis comes from back from the lens? (Sub titles covered that lol) ? [Which surface ?] I know with some photographic lenses you can use an autocollimator and reflective reference plate/ (plane of the image), and rotate the whole lens assembly and correct the flange to be perpendicular to within arc seconds by rotating the lens and correcting the flange (similar to what you show here with a stationary reflected "spot"). With off axis (at different angular) positions of an autocollimator you can also measure radial distortion in a lens... Just an idea you could use or repurpose your rig for. Also makes me think that if a lens could be mounted you could also machine final precision reference surfaces to the lens in a metal holder or flange / cartridge (rather than grinding the glass directly ?). Not sure how thermal expansion of glass vs. Aluminum / Aluminum bronze affects how you "Grip" a lens element precisely in a fairly permanent / bomb proof way (that doesn't slip or creep or fall out of alignment from being jarred ). ? Is it all optical cement for that ? [Just some ideas maybe for future videos etc. ]. [Carl Zeiss makes a thing that looks like an ironing board with an autocollimator for radial distortion measurements and other lens parameters.]. I think I can find a link. . ---> Just as an aside various folks in the Astronomy community talk about pros and cons of the use of carbon fiber, particularly with refractors and anecdotally grumble about CF for refractors not being so good or mumbling about differences in thermal expansion , CF having a -ve coeff. for Thermal expansion etc. Do you have any ideas about that (I'm not an astronomer, but interested in advanced optical / photonic systems.). I think I can devise some useful stuff / work for your awesome early 80's rig :-)

[@HuygensOptics]

Hi ED, thanks for all the suggestions. About the size of the laser spot, I think it can be as small as 15-20 pixels on the CCD. On the screen in the video it has different sizes, and that is because of the different magnifications I use to minimize the spot movement. You can use an autocollimator, however if you have a strongly curved lens you might get very differently sized reflections back, I have no Idea how that works out. Basically you are viewing the reflections throught a straw (inside of the hollow axis is only 8mm) so there is very little room to play. Even finding the reflected laser spot is sometimes tricky. But I agree there is plenty of room for improvement. You can keep the lenses in place by using a little nail polish on the sides (between lens and cup) after you have aligned the lens. also use some on the top surface. It is very easy to damage the glass or a coating with this type of tool, both with aluminium and brass. Carbon fiber enforced materials are generally stiff, but the CTE is still quite high because of the resin. I don't see many advantages over aluminium / steel except maybe for the weight aspect or the aestetics. I'm no expert on this though.

[@user-mm1uf4on2g]

Очень познавательно, спасибо.

[@SubTroppo]

Fascinating. I wonder how long it took to become skilled with this machine. I am going to look up more of your videos from years gone by. ps Here am I wondering how to clean the lenses of a cheap pair of binoculars I bought for a few Australian dollars in a charity shop (small enough to hang around the neck when cycling).

[@alfakrab6134]

I love your Channel

[@lst141]

May I suggest you to finish you casts with what now is a famous citation “ I hope that you learned something today”. By Louis Rossman, a newyorker apple repairman that has an atitude with his bread provider! Now we know why Leica and zeiss were so expensive optical systems….

[@chosen_none]

Wow, there's no precision like optical prevision :) Is that lens group an Apochromat?

[@ericlotze7724]

It would be complex, but perhaps attach steppers/servos on the dials for CNC -> Mechanical -> Device?

[@ericlotze7724]

I would be willing to help with development.

[@HuygensOptics]

Thanks. Actually I have looked into this and it is possible. It would simplify the construction considerably, since some degrees of freedom are now intertwined. But since I use this machine so little it's actually not worth the effort at this moment. Maybe I will make a project of it in the future.

[@georhodiumgeo9827]

When you can’t pass up a good deal on a tool so you find a project for the tool. I also have fallen into some of those traps.

[@dgalvarez]

Haha. I enjoyed the finish of the project. Too much work for that result. This remember when my fiends ask to me to make some stuff in my cave and I immediately think about the time I'll need to make that "simple task" 😂

[@johnsmith-000]

Great video, a always. I can lend you my hundred or so pairs of biconcave/biconvex lenses if you need something to train centering;) I wanted to make viewfinders for underwater camera housings, and tried to reverse engineer the viewfinder I had at hand, but I must have done something wrong, as the new lenses didn't work as expected, and I finally gave up.

[@Spark-Hole]

Thanks you, I love the knowledge you have given. Is that Hungarian accent?

[@pietpaaltjes7419]

That is a Dutch accent :-)

[@BracaPhoto]

Will the "stretch" in the chain create accuracy variations over time ?? I ran into that once and it took a few weeks to figure out the root cause 👍👍

[@camelotorc2]

I hope the customer atleast paid for all your efforts

[@twoalpha09]

Wow I used the LOH LZ-80 more than 40 years ago did not think they are still around

[@mantapbetul6686]

Nicely may the God Bless you.🙏

[@omicron0mega]

Mate, you know your glass.

[@alec4672]

5:50 idk if this is just an American thing but in English here we call it cam logic. A physically 'programmed' system.

[@alexandre.campinas]

thanks!

[@ilkersar7087]

thx a lot!

[@tolkienfan1972]

Awesome

[@marklimbrick]

I saw this years ago. Now I want to ask a question. When a polished lens is edged like this, does the glass surface distort at all?

[@HuygensOptics]

Not by much, but very slightly is possible since introducing these small cracks can introduce some stress in the material.

[@vmiguel1988]

I think you should start making some lenses, I know a lot of makers that would love to have some custom optics 😁

[@HuygensOptics]

I know for sure that is indeed the case. However, making accurate single lenses is very time consuming and therefore expensive. I don't think many people would like to spend a 1000+ euro's on a single lens, especially if they need more than one.

[@Kargoneth]

Hmm. Well, at least your machine is on top form now.

[@davidbrandenburg8029]

I thought those scopes only used mirrors not apochromatic lenses, what kind of scope is that?

[@himeccms893]

How about a video on how an amateur can re-glue a delaminated set of lens? I've got a few compact cameras with these faulty lens, not worth paying to have them fixed. I'm thinking of making use of an old hard disk drive to spin the lens and glue it. Maybe a cheap diode laser to center it?

[@bemusedindian8571]

Best ending ever.

[@TomeRodrigo]

That ending :D

[@Kargoneth]

You have to hope that each face of the lens has a co-linear axis of rotation.

[@MrScooter46290]

I love making lenses, and mirrors. I wish we all could easily get orders to make stuff. Is there a buisness, to person in garage order bidding process. Does anybody know of some way or place to get orders?

[@bobweiram6321]

You can use this laser technique to align a lathe tailstock to a headstock.

[@badranalfalaki9881]

How can i puy the lenses like 100 mm ، convex lens , and concave lens ,

[@HuygensOptics]

try surplusshed.com

[@17THSTREETMARKET]

You are to lens centering what Persig was to motorcycle maintenance. Ahh, science.

[@tigertiger1699]

🙏🙏🙏🙏🙏

[@daviperes]

👍🏻

[@ErikAnders]

Wow

[@gustavgnoettgen]

They polished Steve Rogers in the same machine.

[@lioneloconnor4785]

😂😂😂awaiting part 2

[@MikheilGhvinianidze]

That is the same reason why so Manny 3D printers got returned back to the store.

[@ddegn]

Look on the bright side. You have a new lathe.

[@martinmiglio]

machining on the tap scares the h*ll out of me

[@Kargoneth]

Up to 58 adjustment steps. Yikes! Better make a checklist!

[@foxtrot2320]

Why I have watched an entire video of something that doesn't interest me is beyond me.. Must say it was quite a shame for it to not end up being used after all, as I was looking forward to seeing it.

[@helmut666kohl]

Tho he used it as a super high precision MacGyver lathe - so there is that…

[@fatihdurmaz9826]

hehehehe

[@reidflemingworldstoughestm1394]

All dressed up and nowhere to go.

[@trollmcclure1884]

no lenses to center. Yeah, I hate when that happens

[@teresashinkansen9402]

Amateur astronomers are some quite special people, there are many brilliant and nice people but many others draw parallels to audiophiles and their irrational preoccupation of equipment quality, spending thousands for marginal improvements in quality so they get off to watching barely improved airy disks and becoming clear examples of the placebo effect, describing optical feats far beyond what the aperture might enable to. Yet they berate you for buying a non boutique OTA that has a strehl ratio of less than .90 "I tell you, can see the volcanic plumes of Io on my Questar 3.5 inch" "Wow! nice photo of Jupiter, the red spot looks nice definitely smaller than some 5 years ago, did you took it with a Tak? probably 6 inch, What!? its not a Tak? its just a mass produced OTA? mmm I see why it lacks contrast and vivrance, also I think it has some spherical aberration you should go get checked that, mmm i think might also have some roughness on the mirror. I have 30 years of experience! so believe me, I can see lighting bolts in the storm with my 99999$ triplet apo Tak, its .98 strehl just cuts thorough seeing, my 50 year old diabetic eyesight its well trained better than any silly digital contraption! photon to retina its the best!"