Focus on Simon Ploessl

Discuss telescope eyepieces.
User avatar
mikemarotta
Orion Spur Ambassador
Articles: 0
Offline
Posts: 662
Joined: Sun Nov 17, 2019 2:37 pm
4
Location: Austin, Texas, USA
Status:
Offline

TSS Awards Badges

Focus on Simon Ploessl

#1

Post by mikemarotta »


(An earlier version appeared in the December 2020 issue of Sidereal Times newsletter of the Austin Astronomical Society.

The Ploessl ocular (“eyepiece”) is easily the most popular design in the hobby. Regardless of focal length, from 40 mm to 4 mm, they are common because they are inexpensive and they reasonably support the limits of the largest amateur instruments. Better designs are available, but at a greater cost. Thus, the Ploessl is the first choice, whether for a refractor, reflector, or catadioptric telescope. For all of its ubiquity, its inventor, Viennese optician Simon Georg Ploessl is not widely known among astronomers.

First of all, he spelled his name Plößl and that almost rhymes with the English word “vessel.” The character that looks like a capital-B ß is a double-s. The umlaut-o ö is sounded by rounding your lips to say English long-o, but instead, saying English long-a. If you did not grow up speaking German, then “Plessl” is close enough. That is because three consonants follow the vowel. Each one clips some time off the sounding. The word for “height” die Höhe sounds like an American calling their friend from across a room “hey-yeh” not the short laugh “heh.” For the signature on his nameplates, Ploessl also used the ligature œ (oe), a less common flourish. He also used both versions of his given name: Georg Simon and Simon Georg. If your typewriter has no umlaut vowels (ä ö ü) or a sharp-s (ß), you can use an e and a double-s. Thus, Plößl (which is how he spelled it) is accepted as Plössl or Ploessl, but spelling the name Plossl or saying it that way is wrong.

Georg Simon Plößl (1794-1868) was born in Wieden, which had been an independent villa in the Middle Ages but by the 18th century already lay within Vienna’s shadow. He was the son of a cabinetmaker. And therefore an apprentice in his father’s shop. When he was 18, he left for the optical firm Voigtländer, starting on May 9, 1812. In 1823, he moved back to his father’s home and began his own laboratory and workshop for investigations into the production of optical instruments. In 1828 he was open for sales. At first, Ploessl made microscopes, and he soon became famous for them. His company took a new direction when he sold a microscope to Joseph Franz von Jacquin, professor of botany and chemistry at the University of Vienna. Von Jaquin introduced Ploessl to the astronomer Joseph Johann von Littrow for whom he built a telescope in 1830.

By 1850, in addition to the microscopes which were the primary production of his firm Ploessl had delivered refractors to observatories in Romania, Hungary, Greece, and Russia. In 1851 the firm delivered an 11-inch f/11.8 refractor to the Vizier (some sources say Sultan) of the Ottoman Empire. All of his telescopes had objectives of crown glass. They followed the Fraunhofer design of a concave and convex lens pair, but did not use flint glass which was rarer in large, high-quality blanks. Consequently, the essential element in the design was the secondary lens system, a flint glass ocular that minimized chromatic aberration. Two pairs of lenses match convex and concave curves, and the pairs are separated by a gap. The concave lenses are at the extremes, the convex face each other in the center. That was Ploessl’s stellar achievement.

Three factors kept this system from becoming widely accepted. First, telescopes are durable goods. Better ones have been built since 1610, but the old ones still work. The Ploessl refractor in Athens served the university until 1940. Second, astronomy was a private pursuit for intellectuals of independent means. While Britain had its Royal Astronomer, few such public posts existed elsewhere. Ploessl built telescopes for state enterprises in Greece and Russia, but he built more for wealthy patrons in Hungary, Romania, and Italy. Only with the explosion of science in the 20th century was there any broad consumer demand for the instruments of empirical discovery. Third, as prosperous as the Ploessl firm was, it was a sole proprietorship. When Simon Ploessl was killed by a falling sheet of glass in 1868, there was no one to step into leadership. The firm continued until 1905, but there was no visionary to drive the effort.

For example, consider Pleasures of the Telescope (1901) by Garrett P. Serviss. Serviss was famous as a popularizer of science, especially astronomy. When he was a night editor at The Sun of New York, one of his lecture tours was subsidized by Andrew Carnegie. His passing was noted in a long obituary in Popular Astronomy (August-September 1929). The Pleasures of the Telescope was first published by Putnam in 1901, and then went through several re-publications. Google Books and Hathi Trust provide the 1915 printing by D. Appleton and Company. Serviss described two kinds of eyepieces: positive (Ramsden) and negative (Huygens). He does not mention the Ploessl.

Further Reading
The Hellenic Archives of Scientific Instruments at http://www.hasi.gr/makers/ploessl-georg-simon
https://de.wikipedia.org/wiki/Simon_Plößl
Looking at the Skies for 175 Years: The 162-mm Ploessl Refractor and the 400-mm Gautier Refractor of National Observatory of Athens, Panagiotis, Lazos and Tsimpidas, Dimitrios; XXXVII Scientific Instrument Symposium, 3-7 September 2018, Leiden and Haarlem.
https://en.wikipedia-on-ipfs.org/wiki/Bicske.html
“Plössl-Mikroskope - ein Vergleich mit modernen Geräten,” by E. Steiner and P. Schulz, ©Naturhistorisches Museum Wien, download from www.biologiezentrum.at
“The Achromatic Telescope, Dialytes, and Fluid Lenses--Nebula--Double Stars—Occultations” by the Rev. T. W. Webb, A.M., F.R. A. S., The Intellectual Observer, Groombrdige and Sons, London, No. XLIX, February 1866.
---------------------------------------
Michael E. Marotta
Astro-Tech 115 mm APO Refractor Explore Scientific 102 mm f/6.47 Refractor Explore Scientific 102 mm f/9.8 Refractor Bresser 8-inch Newtonian Reflector Plössls from 40 to 6 mm Nagler Series-1 7mm. nonMeade 14 mm. Mounts: Celestron AVX, Explore Twilight I Alt-Az, Explore EXOS German Equatorial
User avatar
turboscrew
Inter-Galactic Ambassador
Articles: 0
Offline
Posts: 3233
Joined: Sat Jun 20, 2020 9:22 am
3
Location: Nokia, Finland
Status:
Offline

TSS Awards Badges

Re: Focus on Simon Ploessl

#2

Post by turboscrew »


mikemarotta wrote: Wed Dec 16, 2020 6:47 pm (An earlier version appeared in the December 2020 issue of Sidereal Times newsletter of the Austin Astronomical Society.

The Ploessl ocular (“eyepiece”) is easily the most popular design in the hobby. Regardless of focal length, from 40 mm to 4 mm, they are common because they are inexpensive and they reasonably support the limits of the largest amateur instruments. Better designs are available, but at a greater cost. Thus, the Ploessl is the first choice, whether for a refractor, reflector, or catadioptric telescope. For all of its ubiquity, its inventor, Viennese optician Simon Georg Ploessl is not widely known among astronomers.

First of all, he spelled his name Plößl and that almost rhymes with the English word “vessel.” The character that looks like a capital-B ß is a double-s. The umlaut-o ö is sounded by rounding your lips to say English long-o, but instead, saying English long-a. If you did not grow up speaking German, then “Plessl” is close enough. That is because three consonants follow the vowel. Each one clips some time off the sounding. The word for “height” die Höhe sounds like an American calling their friend from across a room “hey-yeh” not the short laugh “heh.” For the signature on his nameplates, Ploessl also used the ligature œ (oe), a less common flourish. He also used both versions of his given name: Georg Simon and Simon Georg. If your typewriter has no umlaut vowels (ä ö ü) or a sharp-s (ß), you can use an e and a double-s. Thus, Plößl (which is how he spelled it) is accepted as Plössl or Ploessl, but spelling the name Plossl or saying it that way is wrong.

Georg Simon Plößl (1794-1868) was born in Wieden, which had been an independent villa in the Middle Ages but by the 18th century already lay within Vienna’s shadow. He was the son of a cabinetmaker. And therefore an apprentice in his father’s shop. When he was 18, he left for the optical firm Voigtländer, starting on May 9, 1812. In 1823, he moved back to his father’s home and began his own laboratory and workshop for investigations into the production of optical instruments. In 1828 he was open for sales. At first, Ploessl made microscopes, and he soon became famous for them. His company took a new direction when he sold a microscope to Joseph Franz von Jacquin, professor of botany and chemistry at the University of Vienna. Von Jaquin introduced Ploessl to the astronomer Joseph Johann von Littrow for whom he built a telescope in 1830.

By 1850, in addition to the microscopes which were the primary production of his firm Ploessl had delivered refractors to observatories in Romania, Hungary, Greece, and Russia. In 1851 the firm delivered an 11-inch f/11.8 refractor to the Vizier (some sources say Sultan) of the Ottoman Empire. All of his telescopes had objectives of crown glass. They followed the Fraunhofer design of a concave and convex lens pair, but did not use flint glass which was rarer in large, high-quality blanks. Consequently, the essential element in the design was the secondary lens system, a flint glass ocular that minimized chromatic aberration. Two pairs of lenses match convex and concave curves, and the pairs are separated by a gap. The concave lenses are at the extremes, the convex face each other in the center. That was Ploessl’s stellar achievement.

Three factors kept this system from becoming widely accepted. First, telescopes are durable goods. Better ones have been built since 1610, but the old ones still work. The Ploessl refractor in Athens served the university until 1940. Second, astronomy was a private pursuit for intellectuals of independent means. While Britain had its Royal Astronomer, few such public posts existed elsewhere. Ploessl built telescopes for state enterprises in Greece and Russia, but he built more for wealthy patrons in Hungary, Romania, and Italy. Only with the explosion of science in the 20th century was there any broad consumer demand for the instruments of empirical discovery. Third, as prosperous as the Ploessl firm was, it was a sole proprietorship. When Simon Ploessl was killed by a falling sheet of glass in 1868, there was no one to step into leadership. The firm continued until 1905, but there was no visionary to drive the effort.

For example, consider Pleasures of the Telescope (1901) by Garrett P. Serviss. Serviss was famous as a popularizer of science, especially astronomy. When he was a night editor at The Sun of New York, one of his lecture tours was subsidized by Andrew Carnegie. His passing was noted in a long obituary in Popular Astronomy (August-September 1929). The Pleasures of the Telescope was first published by Putnam in 1901, and then went through several re-publications. Google Books and Hathi Trust provide the 1915 printing by D. Appleton and Company. Serviss described two kinds of eyepieces: positive (Ramsden) and negative (Huygens). He does not mention the Ploessl.

Further Reading
The Hellenic Archives of Scientific Instruments at http://www.hasi.gr/makers/ploessl-georg-simon
https://de.wikipedia.org/wiki/Simon_Plößl
Looking at the Skies for 175 Years: The 162-mm Ploessl Refractor and the 400-mm Gautier Refractor of National Observatory of Athens, Panagiotis, Lazos and Tsimpidas, Dimitrios; XXXVII Scientific Instrument Symposium, 3-7 September 2018, Leiden and Haarlem.
https://en.wikipedia-on-ipfs.org/wiki/Bicske.html
“Plössl-Mikroskope - ein Vergleich mit modernen Geräten,” by E. Steiner and P. Schulz, ©Naturhistorisches Museum Wien, download from www.biologiezentrum.at
“The Achromatic Telescope, Dialytes, and Fluid Lenses--Nebula--Double Stars—Occultations” by the Rev. T. W. Webb, A.M., F.R. A. S., The Intellectual Observer, Groombrdige and Sons, London, No. XLIX, February 1866.
Plossl is not that bad. In German ä and ö are 'Umlaut', not really totally independent letters (Brot - Brötchen, Haus - Häuser).
And even Germans often use 'ss' instead of 'ß', because it's often more convenient, especially with computers.
(In German nouns are written with capital letter.)

In Finnish ä and ö are independent letters and in original Finnish simple words ä/ö can't co-exist with a/o.
(One simple Finnish word can contain only front and central vowels or central and back vowels.)
Then there's the 'Swedish o': å.
- Juha

Senior Embedded SW Designer
Telescope: OrionOptics XV12, Mount: CEM120, Tri-pier 360 and alternative dobson mount.
Grab 'n go: Omegon AC 102/660 on AZ-3 mount
Eyepieces: 26 mm Omegon SWAN 70°, 15 mm TV Plössl, 12.5 mm Baader Morpheus, 10 mm TV Delos, 6 mm Baader Classic Ortho, 5 mm TV DeLite, 4 mm and 3 mm TV Radians
Cameras: ZWO ASI 294MM Pro, Omegon veLOX 178C
OAG: TS-Optics TSOAG09, ZWO EFW 7 x 36 mm, ZWO filter sets: LRGB and Ha/OIII/SII
Explore Scientific HR 2" coma corrector, Meade x3 1.25" Barlow, TV PowerMate 4x 2"
Some filters (#80A, ND-96, ND-09, Astronomik UHC)
Laptop: Acer Enduro Urban N3 semi-rugged, Windows 11
LAT 61° 28' 10.9" N, Bortle 5

I don't suffer from insanity. I'm enjoying every minute of it.

Image
User avatar
Michael131313 Mexico
Orion Spur Ambassador
Articles: 0
Offline
Posts: 966
Joined: Sun May 12, 2019 5:39 pm
4
Location: San Jose del Valle , Nayarit, Mexico
Status:
Offline

Re: Focus on Simon Ploessl

#3

Post by Michael131313 »


Thanks very much for the history lesson. Enjoyed it very much.
ES AR 102 102mm, f/6.5, ES 254mm f/5 DOB, Obie 10x50, GSO SV 30mm, ES 68° 20mm, ES 82° 14mm, 11mm, 8.8 mm, 6.8mm, 4.7mm. Twilight 1 mount.
User avatar
Makuser United States of America
In Memory
In Memory
Articles: 0
Offline
Posts: 6394
Joined: Mon May 06, 2019 12:53 am
4
Location: Rockledge, FL.
Status:
Offline

TSS Awards Badges

TSS Photo of the Day

Re: Focus on Simon Ploessl

#4

Post by Makuser »


Hi Mike and all. When I started my second delve into astronomy, I started with a Jason 60mm refractor with the Japanese standard .965" eyepieces (1974). I later bought a 32mm 1.25" barrel Plossl from A. Jaegers and had to buy a .965" to 1.25" adapter from University Optics. Wow, what an upgrade for my little telescope. With retirement coming soon at the time (2009), I accumulated the equipment that I now have. I have Plossl 1.25" eyepieces from 4mm to 40mm, but this optical design seems to perform it's best at 20mm, 25mm, and 32mm. I have an older Orion 7" Mak-Cass, and it came with a 1.25" visual/photo back. That's ok, as this instrument is f/15, has a 2,700mm focal length, and it has a very narrow field of view for lunar/planetary work. I use the SmartAstronomy clones of the Orion EdgeOn and Planetary EdgeOn eyepieces with this instrument. However, when I want a lower power eyepiece, I grab this SkyWatcher 32mm Plossl jewel:
Plossl eyepiece.JPG
The telescope manufacturers finally figured out why sell great telescopes and then include inferior eyepieces. So today, most telescope packages that bundle with accessories now include one or more Plossl eyepieces.
After all of these years, the 4 element symmetrical Plossl is still a standard of comparison. Yes, there are better more recent designs and they cost more too, and there are some inferior designs still out there. Also remember that the quality level of some Plossl eyepieces may vary from one manufacturer to another. Lastly, for those of you holding off on getting into the 2" eyepieces (if your focuser will accept them), the 1.25" 32mm Plossl eyepiece is a lot of glass for the money.
Thanks for your wonderful background history of Simon Ploessl Mike, and the best of regards to all.
Marshall
Sky-Watcher 90mm f/13.8 Maksutov-Cassegrain on motorized Multimount
Orion Astroview 120ST f/5 Refractor on EQ3 mount
Celestron Comet Catcher 140mm f/3.64 Schmidt-Newtonian on alt-az mount
Celestron Omni XLT150R f/5 Refractor on CG4 mount with dual axis drives.
Orion 180mm f/15 Maksutov-Cassegrain on CG5-GT Goto mount.
Orion XT12i 12" f/4.9 Dobsonian Intelliscope.
Kamakura 7x35 Binoculars and Celestron SkyMaster 15x70 Binoculars. ZWO ASI 120MC camera.
>)))))*>
User avatar
j.gardavsky Germany
Orion Spur Ambassador
Articles: 0
Offline
Posts: 711
Joined: Mon Sep 23, 2019 1:52 pm
4
Location: Germany
Status:
Offline

TSS Awards Badges

Re: Focus on Simon Ploessl

#5

Post by j.gardavsky »


Hello Michael,

this is a very nice article on Plössl, and especially important for understanding the Austrian school of optics, as marked with the names like Plössl, Voigtländer, Waldstein, Petzval, Reichert, and last but not least Swarovski.

In another forum (CN), I have written a few comments on Plössl, so allow me to put some comments and links here as well.

The carrier in optics by Simon Georg Plössl has been marked by Voigtländer, and possibly even more by professor of mathematics and astronomy Littrow. Thanks to Littrow, Plössl has been appointed to make some astronomy equipments for the Observatory of Vienna, including the eyepieces for the astronomy telescopes.

Here are some possibly less known links to Plössl and to his company:

One of the Plössl's inventions has been the dialytic telescope with a wide spaced doublet,
https://digital.deutsches-museum.de/pro ... imon%27%7D
Its revival is the much later ZEISS (and Hensoldt) Dialyt binocular.

The further Plössl's developments of optics have been made possible due to the heavy flint manufactured by Harrach in Neuwelt, and this heavy flint might have been at the birth of the Plössl's eyepiece around 1840 (not 1860 as in the Wikipedia).
Later, Waldstein has founded a Glasshütte for the heavy flint and other glass materials in Vienna, speeding up the optics developments.
The Plössl's eyepiece has been possibly mounted first on the microscopes, then on the telescopes. With the much cheaper achromatic eyepiece designed by Carl Kellner and under the influence of Carl Friedrich Gauss, the Kellner eyepiece has displaced for the decades to come the expensive Plössl.

Two Plössl's optics are in my collection

https://www.cloudynights.com/gallery/im ... refractor/

https://www.cloudynights.com/gallery/im ... 1862-1870/

Best,
JG
6" F/5 Sky-Watcher achro, 2" BBHS Star Diagonal, 2" zenith prism, 1.25" Takahashi prism
Leica 82mm APO Televid
Eyepieces: Docter UWA; Leica B WW and WW Asph. Zoom; Leica HC Plan S and L, monocentric; Pentax SMC XW, O-, XO; Tak MC O, Carl Zeiss B WW, and Pl, E-Pl, S-Pl, W-Pl;
Swarovski SW; Baader Symmetric Diascope Edition; Nikon NAV SW, ; TMB supermonocentric; Rodenstock; Vixen HR; TV Delos
Filters: Astrodon, Astronomik, Baader, Balzers, Zeiss West and East, Lumicon
Binoculars (7x42 up to 15x85): Docter Nobilem, Leica Ultravid, Nikon Astroluxe, Swarovski EL Swarovision; BA8 (Kunming Optical)
User avatar
Bigzmey United States of America
Moderator
Moderator
Articles: 8
Online
Posts: 7548
Joined: Sat May 11, 2019 7:55 pm
4
Location: San Diego, CA USA
Status:
Online

TSS Awards Badges

Re: Focus on Simon Ploessl

#6

Post by Bigzmey »


"but spelling the name Plossl or saying it that way is wrong." I am afraid this ship has sailed. If majority of speakers use misspelled word long enough it becomes norm. This is how language evolves.

https://www.highpointscientific.com/bra ... -eyepieces
https://www.telescope.com/Orion-Sirius- ... s/e/51.uts
https://agenaastro.com/eyepieces/1-25-e ... lossl.html
Scopes: Stellarvue: SV102ED; Celestron: 9.25" EdgeHD, 8" SCT, 150ST, Onyx 80ED; iOptron: Hankmeister 6" Mak; SW: 7" Mak; Meade: 80ST.
Mounts: SW: SkyTee2, AzGTi; iOptron: AZMP; ES: Twilight I; Bresser: EXOS2; UA: MicroStar.
Binos: APM: 100-90 APO; Canon: IS 15x50; Orion: Binoviewer, LG II 15x70, WV 10x50, Nikon: AE 16x50, 10x50, 8x40.
EPs: Pentax: XWs & XFs; TeleVue: Delites, Panoptic & Plossls; ES: 68, 62; Vixen: SLVs; Baader: BCOs, Aspherics, Mark IV.
Diagonals: Baader: BBHS mirror, Zeiss Spec T2 prism, Clicklock dielectric; TeleVue: Evebrite dielectric; AltairAstro: 2" prism.
Filters: Lumicon: DeepSky, UHC, OIII, H-beta; Baader: Moon & SkyGlow, Contrast Booster, UHC-S, 6-color set; Astronomik: UHC.

Observing: DSOs: 3106 (Completed: Messier, Herschel 1, 2, 3. In progress: H2,500: 2180, S110: 77). Doubles: 2382, Comets: 34, Asteroids: 255
User avatar
notFritzArgelander
In Memory
In Memory
Articles: 0
Offline
Posts: 14925
Joined: Fri May 10, 2019 4:13 pm
4
Location: Idaho US
Status:
Offline

TSS Awards Badges

Re: Focus on Simon Ploessl

#7

Post by notFritzArgelander »


Bigzmey wrote: Tue Feb 16, 2021 10:46 pm "but spelling the name Plossl or saying it that way is wrong." I am afraid this ship has sailed. If majority of speakers use misspelled word long enough it becomes norm. This is how language evolves.

https://www.highpointscientific.com/bra ... -eyepieces
https://www.telescope.com/Orion-Sirius- ... s/e/51.uts
https://agenaastro.com/eyepieces/1-25-e ... lossl.html
As the Borg would say "resistance is futile". I would say "It may be futile, but resistance is a duty". :lol:
Scopes: Refs: Orion ST80, SV 80EDA f7, TS 102ED f11 Newts: AWB 130mm, f5, Z12 f5; Cats: VMC110L, Intes MK66,VMC200L f9.75 EPs: KK Fujiyama Orthoscopics, 2x Vixen NPLs (40-6mm) and BCOs, Baader Mark IV zooms, TV Panoptics, Delos, Plossl 32-8mm. Mixed brand Masuyama/Astroplans Binoculars: Nikon Aculon 10x50, Celestron 15x70, Baader Maxbright. Mounts: Star Seeker IV, Vixen Porta II, Celestron CG5
User avatar
j.gardavsky Germany
Orion Spur Ambassador
Articles: 0
Offline
Posts: 711
Joined: Mon Sep 23, 2019 1:52 pm
4
Location: Germany
Status:
Offline

TSS Awards Badges

Re: Focus on Simon Ploessl

#8

Post by j.gardavsky »


It is like "dividing by zero"
You can't prevent people doing it, and it looks like increasingly widespread and popular. However still fatally wrong, I am afraid.

It happened to come up at right time to my breakfest coffee,
JG
6" F/5 Sky-Watcher achro, 2" BBHS Star Diagonal, 2" zenith prism, 1.25" Takahashi prism
Leica 82mm APO Televid
Eyepieces: Docter UWA; Leica B WW and WW Asph. Zoom; Leica HC Plan S and L, monocentric; Pentax SMC XW, O-, XO; Tak MC O, Carl Zeiss B WW, and Pl, E-Pl, S-Pl, W-Pl;
Swarovski SW; Baader Symmetric Diascope Edition; Nikon NAV SW, ; TMB supermonocentric; Rodenstock; Vixen HR; TV Delos
Filters: Astrodon, Astronomik, Baader, Balzers, Zeiss West and East, Lumicon
Binoculars (7x42 up to 15x85): Docter Nobilem, Leica Ultravid, Nikon Astroluxe, Swarovski EL Swarovision; BA8 (Kunming Optical)
User avatar
MistrBadgr United States of America
Orion Spur Ambassador
Articles: 0
Offline
Posts: 748
Joined: Sat May 11, 2019 9:27 pm
4
Location: Broken Arrow, Okla, USA
Status:
Offline

TSS Awards Badges

Re: Focus on Simon Ploessl

#9

Post by MistrBadgr »


OK, for someone writing in English, considering that we do not have an "o" with two dots over it, what is the closest to correct way to spell the name?
Bill Steen
Many small scopes, plus a Lightbridge 12, LX 70-8R,6R,6M
Many eyepieces, just not really expensive ones.
User avatar
notFritzArgelander
In Memory
In Memory
Articles: 0
Offline
Posts: 14925
Joined: Fri May 10, 2019 4:13 pm
4
Location: Idaho US
Status:
Offline

TSS Awards Badges

Re: Focus on Simon Ploessl

#10

Post by notFritzArgelander »


MistrBadgr wrote: Wed Feb 17, 2021 10:09 pm OK, for someone writing in English, considering that we do not have an "o" with two dots over it, what is the closest to correct way to spell the name?
Ploessl. If your font doesn't have vowels with umlaut (the two dots) adding an "e" is what the umlaut abbreviates.
Scopes: Refs: Orion ST80, SV 80EDA f7, TS 102ED f11 Newts: AWB 130mm, f5, Z12 f5; Cats: VMC110L, Intes MK66,VMC200L f9.75 EPs: KK Fujiyama Orthoscopics, 2x Vixen NPLs (40-6mm) and BCOs, Baader Mark IV zooms, TV Panoptics, Delos, Plossl 32-8mm. Mixed brand Masuyama/Astroplans Binoculars: Nikon Aculon 10x50, Celestron 15x70, Baader Maxbright. Mounts: Star Seeker IV, Vixen Porta II, Celestron CG5
User avatar
Ylem United States of America
Universal Ambassador
Articles: 0
Offline
Posts: 7477
Joined: Sun May 12, 2019 2:54 am
4
Location: Ocean County, New Jersey
Status:
Offline

TSS Photo of the Day

Re: Focus on Simon Ploessl

#11

Post by Ylem »


Thanks Mike for that great article 🙂

I love my Plossls, they
make up all but 4 of my EPs. Of course it's life in the slow lane around here other than an ST-80 :)
Clear Skies,
-Jeff :telescopewink:


Member; ASTRA-NJ



Orion 80ED
Celestron C5, 6SE, Celestar 8
Vixen Porta Mount ll
Coronado PST
A big box of Plossls
Little box of filters
:D



User avatar
Bigzmey United States of America
Moderator
Moderator
Articles: 8
Online
Posts: 7548
Joined: Sat May 11, 2019 7:55 pm
4
Location: San Diego, CA USA
Status:
Online

TSS Awards Badges

Re: Focus on Simon Ploessl

#12

Post by Bigzmey »


notFritzArgelander wrote: Wed Feb 17, 2021 10:11 pm
MistrBadgr wrote: Wed Feb 17, 2021 10:09 pm OK, for someone writing in English, considering that we do not have an "o" with two dots over it, what is the closest to correct way to spell the name?
Ploessl. If your font doesn't have vowels with umlaut (the two dots) adding an "e" is what the umlaut abbreviates.
I know it is correct, but it looks unnatural. :lol:
Scopes: Stellarvue: SV102ED; Celestron: 9.25" EdgeHD, 8" SCT, 150ST, Onyx 80ED; iOptron: Hankmeister 6" Mak; SW: 7" Mak; Meade: 80ST.
Mounts: SW: SkyTee2, AzGTi; iOptron: AZMP; ES: Twilight I; Bresser: EXOS2; UA: MicroStar.
Binos: APM: 100-90 APO; Canon: IS 15x50; Orion: Binoviewer, LG II 15x70, WV 10x50, Nikon: AE 16x50, 10x50, 8x40.
EPs: Pentax: XWs & XFs; TeleVue: Delites, Panoptic & Plossls; ES: 68, 62; Vixen: SLVs; Baader: BCOs, Aspherics, Mark IV.
Diagonals: Baader: BBHS mirror, Zeiss Spec T2 prism, Clicklock dielectric; TeleVue: Evebrite dielectric; AltairAstro: 2" prism.
Filters: Lumicon: DeepSky, UHC, OIII, H-beta; Baader: Moon & SkyGlow, Contrast Booster, UHC-S, 6-color set; Astronomik: UHC.

Observing: DSOs: 3106 (Completed: Messier, Herschel 1, 2, 3. In progress: H2,500: 2180, S110: 77). Doubles: 2382, Comets: 34, Asteroids: 255
User avatar
mikemarotta
Orion Spur Ambassador
Articles: 0
Offline
Posts: 662
Joined: Sun Nov 17, 2019 2:37 pm
4
Location: Austin, Texas, USA
Status:
Offline

TSS Awards Badges

Re: Focus on Simon Ploessl

#13

Post by mikemarotta »


MistrBadgr wrote: Wed Feb 17, 2021 10:09 pm OK, for someone writing in English, considering that we do not have an "o" with two dots over it, what is the closest to correct way to spell the name?
As Fritz said, you can use the e. It is in the original post:
If your typewriter has no umlaut vowels (ä ö ü) or a sharp-s (ß), you can use an e and a double-s. Thus, Plößl (which is how he spelled it) is accepted as Plössl or Ploessl, but spelling the name Plossl or saying it that way is wrong.
I deleted a paragraph about that. During the Middle Ages, the writing was oe and ue and ae. The llttie e went over the other vowels. Then to save time, the monks in the scriptorium used the double dot. It is similar to the Spanish "cedilla" under the C to show the s-sound. It comes from Zedilla, little Z, a mark put under the C to show that it was not hard like a K.

More than you want to know?
---------------------------------------
Michael E. Marotta
Astro-Tech 115 mm APO Refractor Explore Scientific 102 mm f/6.47 Refractor Explore Scientific 102 mm f/9.8 Refractor Bresser 8-inch Newtonian Reflector Plössls from 40 to 6 mm Nagler Series-1 7mm. nonMeade 14 mm. Mounts: Celestron AVX, Explore Twilight I Alt-Az, Explore EXOS German Equatorial
User avatar
mikemarotta
Orion Spur Ambassador
Articles: 0
Offline
Posts: 662
Joined: Sun Nov 17, 2019 2:37 pm
4
Location: Austin, Texas, USA
Status:
Offline

TSS Awards Badges

Re: Focus on Simon Ploessl

#14

Post by mikemarotta »


j.gardavsky wrote: Tue Feb 16, 2021 7:40 pm In another forum (CN), I have written a few comments on Plössl, so allow me to put some comments and links here as well.
Two Plössl's optics are in my collection
https://www.cloudynights.com/gallery/im ... refractor/
https://www.cloudynights.com/gallery/im ... 1862-1870/
Thanks for the links. Those are very nice additions to any collection.
JG: The Plössl's eyepiece has been possibly mounted first on the microscopes, then on the telescopes.
Yes, Ploessl began making microscopes and developed his oculars for them. They earned him a fine reputation in Vienna among the medical community.
His company took off (and took a new direction) when he sold a microscope to Joseph Franz von Jacquin, professor of botany and chemistry at the University of Vienna. Von Jaquin introduced Ploessl to the astronomer Joseph Johann von Littrow for whom he built a telescope in 1830.

You can read my longer artlcle in this newsletter. (Same stuff, a few more details.)
http://austinastro.wildapricot.org/reso ... 202012.pdf

Mike M.
---------------------------------------
Michael E. Marotta
Astro-Tech 115 mm APO Refractor Explore Scientific 102 mm f/6.47 Refractor Explore Scientific 102 mm f/9.8 Refractor Bresser 8-inch Newtonian Reflector Plössls from 40 to 6 mm Nagler Series-1 7mm. nonMeade 14 mm. Mounts: Celestron AVX, Explore Twilight I Alt-Az, Explore EXOS German Equatorial
User avatar
MistrBadgr United States of America
Orion Spur Ambassador
Articles: 0
Offline
Posts: 748
Joined: Sat May 11, 2019 9:27 pm
4
Location: Broken Arrow, Okla, USA
Status:
Offline

TSS Awards Badges

Re: Focus on Simon Ploessl

#15

Post by MistrBadgr »


mikemarotta wrote: Wed Feb 17, 2021 10:36 pm
MistrBadgr wrote: Wed Feb 17, 2021 10:09 pm OK, for someone writing in English, considering that we do not have an "o" with two dots over it, what is the closest to correct way to spell the name?
As Fritz said, you can use the e. It is in the original post:
If your typewriter has no umlaut vowels (ä ö ü) or a sharp-s (ß), you can use an e and a double-s. Thus, Plößl (which is how he spelled it) is accepted as Plössl or Ploessl, but spelling the name Plossl or saying it that way is wrong.
I deleted a paragraph about that. During the Middle Ages, the writing was oe and ue and ae. The llttie e went over the other vowels. Then to save time, the monks in the scriptorium used the double dot. It is similar to the Spanish "cedilla" u:)nder the C to show the s-sound. It comes from Zedilla, little Z, a mark put under the C to show that it was not hard like a K.

More than you want to know?
Thanks, that is just right! :)
Bill Steen
Many small scopes, plus a Lightbridge 12, LX 70-8R,6R,6M
Many eyepieces, just not really expensive ones.
User avatar
j.gardavsky Germany
Orion Spur Ambassador
Articles: 0
Offline
Posts: 711
Joined: Mon Sep 23, 2019 1:52 pm
4
Location: Germany
Status:
Offline

TSS Awards Badges

Re: Focus on Simon Ploessl

#16

Post by j.gardavsky »


Thank you Mike for the article!

The Plössl's optics belongs to the collectibles, and the small telescope I have has been seen over the last decades only three times, once offered by the Dorotheum Auction House in Vienna, one in a collection of another friend in Germany, and one in my collection.
I have started collecting the historical optics around 1972, just to put it into a retroperspective.

The essential volume of the items manufactured by Plössl have been the telescopes for the survey and military, followed by the Galilean binoculars and opera glasses - theater perspective in Plössl's terminology.
The smaller volumes of the microscopes, and the even smaller numbers of the astronomy telescopes, represent the expensive optical instruments, manufactured upon order.

Next to the complete optical instruments, Plössl has manufactured the terrestrial and the astronomy eyepieces, which have been mounted in the telescopes by other manufacturers, or used as replacement parts, or just as accessories, like for the widespread Fraunhofer refractors.

Back to the Plössl's eyepiece.
The optics design may have roots in the tandem doublet achromat, as used in the early days of the microscope objectives. To turn this type of design into an eyepiece, has required the heavy flint glass with a large refractive index, provided by the Harrach's Glasshütte. The mathematics behind the design might have been from Littrow, including the idea of the aplanatic form of the lenses.

Tha aplanatic design has been later used by Reichert ins his remake of the Kellner eyepiece for the microscopes, and by Steinheil in his astronomy eyepiece, both of them I have in my collection.

Back to the Plössl's dialyt telescope
The design, initiated by Littrow, has made it possible to increase the speed of a telescope and to flatten the field, by widening the distance between the crown lens and the flint lens of the classic Fraunhofer air spaced doublet. On the costs reasons, this has also made sense on the large refractors. Herewith, the dialyt is no way a sinle lens telescope.
The small Plössl's refractors have been using cemented doublets, like Dollond and Ramsden.

The last years of Plössl
Since around 1860, the sales and marketing of the Plössl's optics have been through the Rospini's photography shop in Vienna. Plössl has been in charge of manufacturing and technology. The PLÖSSL opera glasses in my collection are from this time.
Herewith the entry in the English WIKI, stating that the Plössl eyepieces has been designed around 1860, looks to be wrong.

This is an amazing historical perspective of the development of optics and of the related mathematics during the first half of the 19th century.

Best,
JG
6" F/5 Sky-Watcher achro, 2" BBHS Star Diagonal, 2" zenith prism, 1.25" Takahashi prism
Leica 82mm APO Televid
Eyepieces: Docter UWA; Leica B WW and WW Asph. Zoom; Leica HC Plan S and L, monocentric; Pentax SMC XW, O-, XO; Tak MC O, Carl Zeiss B WW, and Pl, E-Pl, S-Pl, W-Pl;
Swarovski SW; Baader Symmetric Diascope Edition; Nikon NAV SW, ; TMB supermonocentric; Rodenstock; Vixen HR; TV Delos
Filters: Astrodon, Astronomik, Baader, Balzers, Zeiss West and East, Lumicon
Binoculars (7x42 up to 15x85): Docter Nobilem, Leica Ultravid, Nikon Astroluxe, Swarovski EL Swarovision; BA8 (Kunming Optical)
User avatar
Ruud
Orion Spur Ambassador
Articles: 0
Offline
Posts: 813
Joined: Sun Feb 09, 2020 9:56 pm
4
Location: the Netherlands
Status:
Offline

Re: Focus on Simon Ploessl

#17

Post by Ruud »


For á ö û è and so on find out about the keyboard setting "United States-International" (that's on Windows).

---

I like a good Plössl. The long discontinued 7mm Televue 'smoothy' is amazing. I also have a 26mm TV smoothy and used to have their 55mm as well. The inexpensive GSO 32mm is excellent value.

Plössls' handicap is their eye relief (about 70% of their focal length): too long for a 55mm, too short under 10mm. For shorter focal lengths though a Barlow helps as it will stretch out the eye relief a bit, and my 7mm with 2.5x Barlow is a usable combination that works really well on the planets.
7x50 Helios Apollo 8x42 Bresser Everest 73mm f/5.9 WO APO 4" f/5 TeleVue Genesis 6" f/10 Celestron 6SE 0.63x reducer 1.8, 2, 2.5 and 3x Barlows eyepieces from 4.5 to 34mm
User avatar
j.gardavsky Germany
Orion Spur Ambassador
Articles: 0
Offline
Posts: 711
Joined: Mon Sep 23, 2019 1:52 pm
4
Location: Germany
Status:
Offline

TSS Awards Badges

Re: Focus on Simon Ploessl

#18

Post by j.gardavsky »


Ruud wrote: Sat Feb 20, 2021 10:52 am For á ö û è and so on find out about the keyboard setting "United States-International" (that's on Windows).

---

I like a good Plössl. The long discontinued 7mm Televue 'smoothy' is amazing. I also have a 26mm TV smoothy and used to have their 55mm as well. The inexpensive GSO 32mm is excellent value.

Plössls' handicap is their eye relief (about 70% of their focal length): too long for a 55mm, too short under 10mm. For shorter focal lengths though a Barlow helps as it will stretch out the eye relief a bit, and my 7mm with 2.5x Barlow is a usable combination that works really well on the planets.
Yes,
the short focus Plössls can be barlowed.

Instead of the long focus Plössls, I prefer the (field stop - 2 - 1) König design, like the Leica f=32mm.

https://www.cloudynights.com/gallery/im ... eyepieces/

and actually, all these three Leicas are better than the long Plössls.
Otherwise, the Plössls around f=15mm are a very good choice - even the 15mm Plössl from the kit to my refractor has shown the outer ears of the Dumbbell Nebula.

For any longer focus than f=32mm, I am considering to try the Reichert (Vienna), maybe just for the sake of my curiosity.

Best,
JG
6" F/5 Sky-Watcher achro, 2" BBHS Star Diagonal, 2" zenith prism, 1.25" Takahashi prism
Leica 82mm APO Televid
Eyepieces: Docter UWA; Leica B WW and WW Asph. Zoom; Leica HC Plan S and L, monocentric; Pentax SMC XW, O-, XO; Tak MC O, Carl Zeiss B WW, and Pl, E-Pl, S-Pl, W-Pl;
Swarovski SW; Baader Symmetric Diascope Edition; Nikon NAV SW, ; TMB supermonocentric; Rodenstock; Vixen HR; TV Delos
Filters: Astrodon, Astronomik, Baader, Balzers, Zeiss West and East, Lumicon
Binoculars (7x42 up to 15x85): Docter Nobilem, Leica Ultravid, Nikon Astroluxe, Swarovski EL Swarovision; BA8 (Kunming Optical)
User avatar
mikemarotta
Orion Spur Ambassador
Articles: 0
Offline
Posts: 662
Joined: Sun Nov 17, 2019 2:37 pm
4
Location: Austin, Texas, USA
Status:
Offline

TSS Awards Badges

Re: Focus on Simon Ploessl

#19

Post by mikemarotta »


j.gardavsky wrote: Thu Feb 18, 2021 12:26 pm Thank you Mike for the article! The Plössl's optics belongs to the collectibles, and the small telescope I have has been seen over the last decades only three times,... This is an amazing historical perspective of the development of optics and of the related mathematics during the first half of the 19th century.
Viel' Dank' auch für Ihrer Beobachtung. In 1997-1998, I worked for Carl Zeiss Oberkochen in their Detroit office. Es ist eine lange Weile gewesen seitdem ich Deutsch gesprochen habe. I was a trainer in factory automation with Zeiss equipment in General Motors factories. Aber ich habe auch ein Lehrbuch für Optik von Deutsch bis Englisch übersetztet. Jenseits, prefer I much more for daily chat English to write.

(I also can recite some Rilke.)
---------------------------------------
Michael E. Marotta
Astro-Tech 115 mm APO Refractor Explore Scientific 102 mm f/6.47 Refractor Explore Scientific 102 mm f/9.8 Refractor Bresser 8-inch Newtonian Reflector Plössls from 40 to 6 mm Nagler Series-1 7mm. nonMeade 14 mm. Mounts: Celestron AVX, Explore Twilight I Alt-Az, Explore EXOS German Equatorial
User avatar
j.gardavsky Germany
Orion Spur Ambassador
Articles: 0
Offline
Posts: 711
Joined: Mon Sep 23, 2019 1:52 pm
4
Location: Germany
Status:
Offline

TSS Awards Badges

Re: Focus on Simon Ploessl

#20

Post by j.gardavsky »


Hello Michael,

very interesting!
Your times with GM, have it been the geometry measurement systems for the body in white manufacturing?

Best regards,
JG

PS: Your German is perfect!
6" F/5 Sky-Watcher achro, 2" BBHS Star Diagonal, 2" zenith prism, 1.25" Takahashi prism
Leica 82mm APO Televid
Eyepieces: Docter UWA; Leica B WW and WW Asph. Zoom; Leica HC Plan S and L, monocentric; Pentax SMC XW, O-, XO; Tak MC O, Carl Zeiss B WW, and Pl, E-Pl, S-Pl, W-Pl;
Swarovski SW; Baader Symmetric Diascope Edition; Nikon NAV SW, ; TMB supermonocentric; Rodenstock; Vixen HR; TV Delos
Filters: Astrodon, Astronomik, Baader, Balzers, Zeiss West and East, Lumicon
Binoculars (7x42 up to 15x85): Docter Nobilem, Leica Ultravid, Nikon Astroluxe, Swarovski EL Swarovision; BA8 (Kunming Optical)
Post Reply

Create an account or sign in to join the discussion

You need to be a member in order to post a reply

Create an account

Not a member? register to join our community
Members can start their own topics & subscribe to topics
It’s free and only takes a minute

Register

Sign in

Return to “Eyepieces”