Some legacy optics with a tale to tell

[ColinM]

I know several members of NG understand Dutch & will be able to share the finer details in this article.
I had to make do with Chrome automatically translating the page to English.

Seems this well known 17th century builder of telescopes made designs that didn't work well for anyone who didn't also have his particular type of bad eyesight.

https://nos.nl/artikel/2465825-onderzoeker-telescopenbouwer-christiaan-huygens-was-bijziend

It may he that Huygens wouldn't have appreciated being put in the "What the Nerds Do" section and if so, I'm sorry.

[Fons Baerken]

Christiaan Huygens was nearsighted by minus 1 point 5, so his telescope lenses werent sharp

[Hugh_3170]

Most inventions lead to prototypes and then to pre-production examples, so they (Huygens telescopes etc) definitely would have had to go through a "nerd" phase.   

So I think that Huygens would forgive you.  Besides, his place in the history of optics and physics is firmly set in concrete - so nothing we can say will change that. 

................................................

It may he that Huygens wouldn't have appreciated being put in the "What the Nerds Do" section and if so, I'm sorry.

[Birna Rørslett]

Aha.  I share the same degree of nearsightedness with him. Perhaps the reason why I am a nerd???

By the way, I tried to read the original Dutch post and understood about 1/3 of it. Google translate added the remainder later ....

[Bernard Delley]

if nearsightedness goes with nerd-ness, I must be at high risk ! My prescription is at -4 now. I actually like to walk with my varifocal computer glasses on, which leave about -1 diopters for far views. Fully corrected glasses for star views of course.

The article https://articles.adsabs.harvard.edu/full/seri/ESASP/1278//0000103.000.html  contains interesting detail about Hugens telescopes.
It would be interesting to dig a bit deeper into how the 2 lens eyepiece works to remove color aberrations coming from the principal lens.

The full article of Pietrow goes into these interesting details
https://arxiv.org/pdf/2303.05170.pdf

[Bernard Delley]

nerds or not, after all NikonGear is a group interested in imaging.

As a follow up finding I got into an article on "reading" a fairly famous painting and finding a portrait of Christiaan Huygens in it amongst other things:
https://articles.adsabs.harvard.edu/pdf/2004ESASP1278..157V

I find this fun and interesting.

[Akira]

Sorry to be off-topic, but talking about Huygens, this YouTuber hand-crafted a single piece catadioptric lens (even its aspherical surfaces) on his own!:

https://www.youtube.com/@HuygensOptics

[Hugh_3170]

My eyesight has gone from the nearsightedness that I had when I was younger to normal eyesight in old age. 

On my older SLRs, I have had to remove their correction eyepieces and replace them with plain ones in order to focus.  However my house is now littered with inexpensive reading glasses of various strengths - depending on what I need - e.g. for reading or fixing small objects etc where I need to see in close.  However I can now drive a car without the need for spectacles.

So does this mean that I am now a reformed nerd"?" LOL. 

[Bernard Delley]

Sorry to be off-topic, but talking about Huygens, this YouTuber hand-crafted a single piece catadioptric lens (even its aspherical surfaces) on his own!:

https://www.youtube.com/@HuygensOptics

Thanks for this fun link !
I found the non-mathematical video about grinding glass for a small telescope educational, showing a lot of detail that I did not know, and a lot of fun to watch !